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Zeng Y, Ma G, Li H, Cheng X, Miao X. Significant Power Consumption Reduction and Speed Boosting in Phase Change Memory with Nanocurrent Channels. NANO LETTERS 2024. [PMID: 39316704 DOI: 10.1021/acs.nanolett.4c03900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2024]
Abstract
The excessive power consumption is challenging for phase change memory (PCM) on its way to becoming universal memory in complex hierarchies of memory systems. Here, from the perspective of device structure, by adding a nanocurrent-channel (NCC) layer between the electrode layer and phase change layer, a RESET power consumption reduction by more than 95% and 10 times faster SET speed were realized simultaneously. Through the first principle calculations, Au and SiO2 were screened as the metal and insulating matrix material of NCC layer, respectively. Our PCM device with a Au-SiO2 NCC layer shows an ultralow RESET power consumption, down to 381 fJ, and an ultrafast SET speed (8 ns). Much higher current density near NCC in the phase change layer and thermal barrier effect of insulating matrix material were confirmed by finite element analysis (FEA), and the role of Au nanochannels was revealed by transmission electron microscopy (TEM). Our NCC layer structure provides a simple and practicable method to significantly decrease PCM power consumption.
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Affiliation(s)
- Yuntao Zeng
- School of Integrated Circuits, Hubei Key Laboratory for Advanced Memories, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Ge Ma
- School of Integrated Circuits, Hubei Key Laboratory for Advanced Memories, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Han Li
- School of Integrated Circuits, Hubei Key Laboratory for Advanced Memories, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Xiaomin Cheng
- School of Integrated Circuits, Hubei Key Laboratory for Advanced Memories, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Xiangshui Miao
- School of Integrated Circuits, Hubei Key Laboratory for Advanced Memories, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
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2
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Park SO, Hong S, Sung SJ, Kim D, Seo S, Jeong H, Park T, Cho WJ, Kim J, Choi S. Phase-change memory via a phase-changeable self-confined nano-filament. Nature 2024; 628:293-298. [PMID: 38570686 DOI: 10.1038/s41586-024-07230-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 02/23/2024] [Indexed: 04/05/2024]
Abstract
Phase-change memory (PCM) has been considered a promising candidate for solving von Neumann bottlenecks owing to its low latency, non-volatile memory property and high integration density1,2. However, PCMs usually require a large current for the reset process by melting the phase-change material into an amorphous phase, which deteriorates the energy efficiency2-5. Various studies have been conducted to reduce the operation current by minimizing the device dimensions, but this increases the fabrication cost while the reduction of the reset current is limited6,7. Here we show a device for reducing the reset current of a PCM by forming a phase-changeable SiTex nano-filament. Without sacrificing the fabrication cost, the developed nano-filament PCM achieves an ultra-low reset current (approximately 10 μA), which is about one to two orders of magnitude smaller than that of highly scaled conventional PCMs. The device maintains favourable memory characteristics such as a large on/off ratio, fast speed, small variations and multilevel memory properties. Our finding is an important step towards developing novel computing paradigms for neuromorphic computing systems, edge processors, in-memory computing systems and even for conventional memory applications.
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Affiliation(s)
- See-On Park
- The School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Seokman Hong
- The School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Su-Jin Sung
- The School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Dawon Kim
- The School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Seokho Seo
- The School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Hakcheon Jeong
- The School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Taehoon Park
- The School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Won Joon Cho
- Device Research Center, Samsung Advanced Institute of Technology (SAIT), Samsung Electronics Co., Ltd., Suwon, Republic of Korea
| | - Jeehwan Kim
- Device Research Center, Samsung Advanced Institute of Technology (SAIT), Samsung Electronics Co., Ltd., Suwon, Republic of Korea
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Shinhyun Choi
- The School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea.
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3
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Yang Z, Li B, Wang J, Wang X, Xu M, Tong H, Cheng X, Lu L, Jia C, Xu M, Miao X, Zhang W, Ma E. Designing Conductive-Bridge Phase-Change Memory to Enable Ultralow Programming Power. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2103478. [PMID: 35032111 PMCID: PMC8922100 DOI: 10.1002/advs.202103478] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 11/27/2021] [Indexed: 05/31/2023]
Abstract
Phase-change material (PCM) devices are one of the most mature nonvolatile memories. However, their high power consumption remains a bottleneck problem limiting the data storage density. One may drastically reduce the programming power by patterning the PCM volume down to nanometer scale, but that route incurs a stiff penalty from the tremendous cost associated with the complex nanofabrication protocols required. Instead, here a materials solution to resolve this dilemma is offered. The authors work with memory cells of conventional dimensions, but design/exploit a PCM alloy that decomposes into a heterogeneous network of nanoscale crystalline domains intermixed with amorphous ones. The idea is to confine the subsequent phase-change switching in the interface region of the crystalline nanodomain with its amorphous surrounding, forming/breaking "nano-bridges" that link up the crystalline domains into a conductive path. This conductive-bridge switching mechanism thus only involves nanometer-scale volume in programming, despite of the large areas in contact with the electrodes. The pore-like devices based on spontaneously phase-separated Ge13 Sb71 O16 alloy enable a record-low programming energy, down to a few tens of femtojoule. The new PCM/fabrication is fully compatible with the current 3D integration technology, adding no expenses or difficulty in processing.
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Affiliation(s)
- Zhe Yang
- Wuhan National Laboratory for OptoelectronicsSchool of Optical and Electronic InformationHuazhong University of Science and TechnologyWuhan430074China
| | - Bowen Li
- Wuhan National Laboratory for OptoelectronicsSchool of Optical and Electronic InformationHuazhong University of Science and TechnologyWuhan430074China
| | - Jiang‐Jing Wang
- Center for Alloy Innovation and Design (CAID)State Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China
| | - Xu‐Dong Wang
- Center for Alloy Innovation and Design (CAID)State Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China
| | - Meng Xu
- Wuhan National Laboratory for OptoelectronicsSchool of Optical and Electronic InformationHuazhong University of Science and TechnologyWuhan430074China
| | - Hao Tong
- Wuhan National Laboratory for OptoelectronicsSchool of Optical and Electronic InformationHuazhong University of Science and TechnologyWuhan430074China
| | - Xiaomin Cheng
- Wuhan National Laboratory for OptoelectronicsSchool of Optical and Electronic InformationHuazhong University of Science and TechnologyWuhan430074China
| | - Lu Lu
- The School of MicroelectronicsState Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China
| | - Chunlin Jia
- The School of MicroelectronicsState Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China
| | - Ming Xu
- Wuhan National Laboratory for OptoelectronicsSchool of Optical and Electronic InformationHuazhong University of Science and TechnologyWuhan430074China
| | - Xiangshui Miao
- Wuhan National Laboratory for OptoelectronicsSchool of Optical and Electronic InformationHuazhong University of Science and TechnologyWuhan430074China
| | - Wei Zhang
- Center for Alloy Innovation and Design (CAID)State Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China
| | - En Ma
- Center for Alloy Innovation and Design (CAID)State Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China
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Hu XH, Xiong S. Fabrication of Nanodevices Through Block Copolymer Self-Assembly. FRONTIERS IN NANOTECHNOLOGY 2022. [DOI: 10.3389/fnano.2022.762996] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Block copolymer (BCP) self-assembly, as a novel bottom-up patterning technique, has received increasing attention in the manufacture of nanodevices because of its significant advantages of high resolution, high throughput, low cost, and simple processing. BCP self-assembly provides a very powerful approach to constructing diverse nanoscale templates and patterns that meet large-scale manufacturing practices. For the past 20 years, the self-assembly of BCPs has been extensively employed to produce a range of nanodevices, such as nonvolatile memory, bit-patterned media (BPM), fin field-effect transistors (FinFETs), photonic nanodevices, solar cells, biological and chemical sensors, and ultrafiltration membranes, providing a variety of configurations for high-density integration and cost-efficient manufacturing. In this review, we summarize the recent progress in the fabrication of nanodevices using the templates of BCP self-assembly, and present current challenges and future opportunities.
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5
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Park TW, Park WI. Switching-Modulated Phase Change Memory Realized by Si-Containing Block Copolymers. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2105078. [PMID: 34796645 DOI: 10.1002/smll.202105078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 10/12/2021] [Indexed: 06/13/2023]
Abstract
The phase change memory (PCM) is one of the key enabling memory technologies for next-generation non-volatile memory device applications due to its high writing speed, excellent endurance, long retention time, and good scalability. However, the high power consumption of PCM devices caused by the high switching current from a high resistive state to a low resistive state is a critical obstacle to be resolved before widespread commercialization can be realized. Here, a useful approach to reduce the writing current of PCM, which depends strongly on the contact area between the heater electrode and active layer, by employing self-assembly process of Si-containing block copolymers (BCPs) is presented. Self-assembled insulative BCP pattern geometries can locally block the current path of the contact between a high resistive film (TiN) and a phase-change material (Ge2 Sb2 Te5 ), resulting in a significant reduction of the writing current. Compared to a conventional PCM cell, the BCP-modified PCM shows excellent switching power reduction up to 1/20 given its use of self-assembled hybrid SiFex Oy /SiOx dot-in-hole nanostructures. This BCP-based bottom-up process can be extended to various applications of other non-volatile memory devices, such as resistive switching memory and magnetic storage devices.
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Affiliation(s)
- Tae Wan Park
- Electronic Convergence Materials Division, Korea Institute of Ceramic Engineering and Technology (KICET), 101 Soho-ro, Jinju, 52851, Republic of Korea
- Department of Materials Science and Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Woon Ik Park
- Department of Materials Science and Engineering, Pukyoung National University (PKNU), 45 Yongso-ro, Nam-gu, Busan, 48513, Republic of Korea
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6
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Zhou J, Thapar V, Chen Y, Wu BX, Craig GSW, Nealey PF, Hur SM, Chang TH, Xiong S. Self-Aligned Assembly of a Poly(2-vinylpyridine)- b-Polystyrene- b-Poly(2-vinylpyridine) Triblock Copolymer on Graphene Nanoribbons. ACS APPLIED MATERIALS & INTERFACES 2021; 13:41190-41199. [PMID: 34470104 DOI: 10.1021/acsami.1c08940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Directed self-assembly (DSA) of block copolymers is one of the most promising patterning techniques for patterning sub-10 nm features. However, at such small feature sizes, it is becoming increasingly difficult to fabricate the guiding pattern for the DSA process, and it is necessary to explore alternative guiding methods for DSA to achieve long-range ordered alignment. Here, we report the self-aligned assembly of a triblock copolymer, poly(2-vinylpyridine)-b-polystyrene-b-poly(2-vinylpyridine) (P2VP-b-PS-b-P2VP) on neutral graphene nanoribbons with the gap consisting of a P2VP-preferential silicon oxide (SiO2) substrate via solvent vapor annealing. The assembled P2VP-b-PS-b-P2VP demonstrated long-range, one-dimensional alignment on the graphene substrate in a direction perpendicular to the boundary of the graphene and substrate with a half-pitch size of 8 nm, which greatly alleviates the lithography resolution required for traditional chemoepitaxy DSA. A wide processing window is demonstrated with the gap between graphene stripes varying from 10 to 100 nm, overcoming the restriction on widths of guiding patterns to have commensurate domain spacing. When the gap was reduced to 10 nm, P2VP-b-PS-b-P2VP formed a straight-line pattern on both the graphene and the substrate. Monte Carlo simulations showed that the self-aligned assembly of the triblock copolymer on the graphene nanoribbons is guided at the boundary of parallel and perpendicular lamellae on graphene and SiO2, respectively. Simulations also indicate that the swelling of a system allows for rapid rearrangement of chains and quickly anneal any misaligned grains and defects. The effect of the interaction strength between SiO2 and P2VP on the self-assembly is systematically investigated in simulations.
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Affiliation(s)
- Jing Zhou
- School of Information Science and Technology, Fudan University, Shanghai 200433, China
| | - Vikram Thapar
- School of Polymer Science and Engineering, Chonnam National University, Gwangju 61186, Korea
| | - Yu Chen
- School of Information Science and Technology, Fudan University, Shanghai 200433, China
| | - Bi-Xian Wu
- Graduate Institute of Electronics Engineering, National Taiwan University, Taipei 106, Taiwan
| | - Gordon S W Craig
- Pritzker School of Molecular Engineering, University of Chicago, 5640 S Ellis Avenue, Chicago, Illinois 60637, United States
| | - Paul F Nealey
- Pritzker School of Molecular Engineering, University of Chicago, 5640 S Ellis Avenue, Chicago, Illinois 60637, United States
| | - Su-Mi Hur
- School of Polymer Science and Engineering, Chonnam National University, Gwangju 61186, Korea
| | - Tzu-Hsuan Chang
- Graduate Institute of Electronics Engineering, National Taiwan University, Taipei 106, Taiwan
| | - Shisheng Xiong
- School of Information Science and Technology, Fudan University, Shanghai 200433, China
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7
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High performance floating self-excited sliding triboelectric nanogenerator for micro mechanical energy harvesting. Nat Commun 2021; 12:4689. [PMID: 34344899 PMCID: PMC8333367 DOI: 10.1038/s41467-021-25047-y] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 07/06/2021] [Indexed: 11/08/2022] Open
Abstract
Non-contact triboelectric nanogenerator (TENG) enabled for both high conversion efficiency and durability is appropriate to harvest random micro energy owing to the advantage of low driving force. However, the low output (<10 μC m-2) of non-contact TENG caused by the drastic charge decay limits its application. Here, we propose a floating self-excited sliding TENG (FSS-TENG) by a self-excited amplification between rotator and stator to achieve self-increased charge density, and the air breakdown model of non-contact TENG is given for a maximum charge density. The charge density up to 71.53 μC m-2 is achieved, 5.46 times as that of the traditional floating TENG. Besides, the high output enables it to continuously power small electronics at 3 m s-1 weak wind. This work provides an effective strategy to address the low output of floating sliding TENG, and can be easily adapted to capture the varied micro mechanical energies anywhere.
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8
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Donie YJ, Schlisske S, Siddique RH, Mertens A, Narasimhan V, Schackmar F, Pietsch M, Hossain IM, Hernandez-Sosa G, Lemmer U, Gomard G. Phase-Separated Nanophotonic Structures by Inkjet Printing. ACS NANO 2021; 15:7305-7317. [PMID: 33844505 DOI: 10.1021/acsnano.1c00552] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The spontaneous phase separation of two or more polymers is a thermodynamic process that can take place in both biological and synthetic materials and which results in the structuring of the matter from the micro- to the nanoscale. For photonic applications, it allows forming quasi-periodic or disordered assemblies of light scatterers at high throughput and low cost. The wet process methods currently used to fabricate phase-separated nanostructures (PSNs) limit the design possibilities, which in turn hinders the deployment of PSNs in commercialized products. To tackle this shortcoming, we introduce a versatile and industrially scalable deposition method based on the inkjet printing of a polymer blend, leading to PSNs with a feature size that is tuned from a few micrometers down to sub-100 nm. Consequently, PSNs can be rapidly processed into the desired macroscopic design. We demonstrate that these printed PSNs can improve light management in manifold photonic applications, exemplified here by exploiting them as a light extraction layer and a metasurface for light-emitting devices and point-of-care biosensors, respectively.
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Affiliation(s)
- Yidenekachew J Donie
- Light Technology Institute, Karlsruhe Institute of Technology, Engesserstrasse 13, 76131 Karlsruhe, Germany
| | - Stefan Schlisske
- Light Technology Institute, Karlsruhe Institute of Technology, Engesserstrasse 13, 76131 Karlsruhe, Germany
- InnovationLab, Speyerer Strasse 4, 69115 Heidelberg, Germany
| | - Radwanul H Siddique
- Image Sensor Lab, Samsung Semiconductor, Inc., 2 N Lake Avenue Suite 240, Pasadena, California 91101, United States
- Medical Engineering, California Institute of Technology (Caltech), 1200 E California Boulevard, Pasadena, California 91125, United States
| | - Adrian Mertens
- Light Technology Institute, Karlsruhe Institute of Technology, Engesserstrasse 13, 76131 Karlsruhe, Germany
- Institute of Microstructure Technology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Vinayak Narasimhan
- Medical Engineering, California Institute of Technology (Caltech), 1200 E California Boulevard, Pasadena, California 91125, United States
| | - Fabian Schackmar
- Light Technology Institute, Karlsruhe Institute of Technology, Engesserstrasse 13, 76131 Karlsruhe, Germany
- InnovationLab, Speyerer Strasse 4, 69115 Heidelberg, Germany
- Institute of Microstructure Technology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Manuel Pietsch
- Light Technology Institute, Karlsruhe Institute of Technology, Engesserstrasse 13, 76131 Karlsruhe, Germany
- InnovationLab, Speyerer Strasse 4, 69115 Heidelberg, Germany
| | - Ihteaz M Hossain
- Light Technology Institute, Karlsruhe Institute of Technology, Engesserstrasse 13, 76131 Karlsruhe, Germany
- Institute of Microstructure Technology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Gerardo Hernandez-Sosa
- Light Technology Institute, Karlsruhe Institute of Technology, Engesserstrasse 13, 76131 Karlsruhe, Germany
- InnovationLab, Speyerer Strasse 4, 69115 Heidelberg, Germany
| | - Uli Lemmer
- Light Technology Institute, Karlsruhe Institute of Technology, Engesserstrasse 13, 76131 Karlsruhe, Germany
- InnovationLab, Speyerer Strasse 4, 69115 Heidelberg, Germany
- Institute of Microstructure Technology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Guillaume Gomard
- Light Technology Institute, Karlsruhe Institute of Technology, Engesserstrasse 13, 76131 Karlsruhe, Germany
- Institute of Microstructure Technology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
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9
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Shin JH, Park JH, Seo J, Im TH, Kim JC, Lee HE, Kim DH, Woo KY, Jeong HY, Cho YH, Kim TS, Kang IS, Lee KJ. A Flash-Induced Robust Cu Electrode on Glass Substrates and Its Application for Thin-Film μLEDs. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2007186. [PMID: 33634556 DOI: 10.1002/adma.202007186] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 12/18/2020] [Indexed: 05/04/2023]
Abstract
A robust Cu conductor on a glass substrate for thin-film μLEDs using the flash-induced chemical/physical interlocking between Cu and glass is reported. During millisecond light irradiation, CuO nanoparticles (NPs) on the display substrate are transformed into a conductive Cu film by reduction and sintering. At the same time, intensive heating at the boundary of CuO NPs and glass chemically induces the formation of an ultrathin Cu2 O interlayer within the Cu/glass interface for strong adhesion. Cu nanointerlocking occurs by transient glass softening and interface fluctuation to increase the contact area. Owing to these flash-induced interfacial interactions, the flash-activated Cu electrode exhibits an adhesion energy of 10 J m-2 , which is five times higher than that of vacuum-deposited Cu. An AlGaInP thin-film vertical μLED (VLED) forms an electrical interconnection with the flash-induced Cu electrode via an ACF bonding process, resulting in a high optical power density of 41 mW mm-2 . The Cu conductor enables reliable VLED operation regardless of harsh thermal stress and moisture infiltration under a high-temperature storage test, temperature humidity test, and thermal shock test. 50 × 50 VLED arrays transferred onto the flash-induced robust Cu electrode show high illumination yield and uniform distribution of forward voltage, peak wavelength, and device temperature.
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Affiliation(s)
- Jung Ho Shin
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Jung Hwan Park
- Department of Mechanical Engineering (Department of Aeronautics, Mechanical and Electronic Convergence Engineering), Kumoh National Institute of Technology, 61 Daehak-ro, Gumi, Gyeongbuk, 39177, Republic of Korea
| | - Jeongmin Seo
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Tae Hong Im
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Jong Chan Kim
- UNIST Central Research Facilities (UCRF) and School of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Han Eol Lee
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Do Hyun Kim
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Kie Young Woo
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Hu Young Jeong
- UNIST Central Research Facilities (UCRF) and School of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Yong-Hoon Cho
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Taek-Soo Kim
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Il-Suk Kang
- National Nanofab Center, Korea Advanced Institute of Science and Technology (KAIST), 291, Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Keon Jae Lee
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
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10
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Pinto-Gómez C, Pérez-Murano F, Bausells J, Villanueva LG, Fernández-Regúlez M. Directed Self-Assembly of Block Copolymers for the Fabrication of Functional Devices. Polymers (Basel) 2020; 12:E2432. [PMID: 33096908 PMCID: PMC7589734 DOI: 10.3390/polym12102432] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 10/15/2020] [Accepted: 10/16/2020] [Indexed: 01/17/2023] Open
Abstract
Directed self-assembly of block copolymers is a bottom-up approach to nanofabrication that has attracted high interest in recent years due to its inherent simplicity, high throughput, low cost and potential for sub-10 nm resolution. In this paper, we review the main principles of directed self-assembly of block copolymers and give a brief overview of some of the most extended applications. We present a novel fabrication route based on the introduction of directed self-assembly of block copolymers as a patterning option for the fabrication of nanoelectromechanical systems. As a proof of concept, we demonstrate the fabrication of suspended silicon membranes clamped by dense arrays of single-crystal silicon nanowires of sub-10 nm diameter. Resulting devices can be further developed for building up high-sensitive mass sensors based on nanomechanical resonators.
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Affiliation(s)
- Christian Pinto-Gómez
- Instituto de Microelectrónica de Barcelona (IMB-CNM, CSIC), Campus UAB, 08193 Bellaterra, Spain; (C.P.-G.); (F.P.-M.); (J.B.)
| | - Francesc Pérez-Murano
- Instituto de Microelectrónica de Barcelona (IMB-CNM, CSIC), Campus UAB, 08193 Bellaterra, Spain; (C.P.-G.); (F.P.-M.); (J.B.)
| | - Joan Bausells
- Instituto de Microelectrónica de Barcelona (IMB-CNM, CSIC), Campus UAB, 08193 Bellaterra, Spain; (C.P.-G.); (F.P.-M.); (J.B.)
| | - Luis Guillermo Villanueva
- Advanced NEMS Laboratory, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland;
| | - Marta Fernández-Regúlez
- Instituto de Microelectrónica de Barcelona (IMB-CNM, CSIC), Campus UAB, 08193 Bellaterra, Spain; (C.P.-G.); (F.P.-M.); (J.B.)
- Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
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11
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Jung YH, Hong SK, Wang HS, Han JH, Pham TX, Park H, Kim J, Kang S, Yoo CD, Lee KJ. Flexible Piezoelectric Acoustic Sensors and Machine Learning for Speech Processing. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e1904020. [PMID: 31617274 DOI: 10.1002/adma.201904020] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 08/28/2019] [Indexed: 05/22/2023]
Abstract
Flexible piezoelectric acoustic sensors have been developed to generate multiple sound signals with high sensitivity, shifting the paradigm of future voice technologies. Speech recognition based on advanced acoustic sensors and optimized machine learning software will play an innovative interface for artificial intelligence (AI) services. Collaboration and novel approaches between both smart sensors and speech algorithms should be attempted to realize a hyperconnected society, which can offer personalized services such as biometric authentication, AI secretaries, and home appliances. Here, representative developments in speech recognition are reviewed in terms of flexible piezoelectric materials, self-powered sensors, machine learning algorithms, and speaker recognition.
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Affiliation(s)
- Young Hoon Jung
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Seong Kwang Hong
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Hee Seung Wang
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Jae Hyun Han
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Trung Xuan Pham
- Department of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Hyunsin Park
- Department of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Junyeong Kim
- Department of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Sunghun Kang
- Department of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Chang D Yoo
- Department of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Keon Jae Lee
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
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12
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Lee BY, Kim DH, Park J, Park KI, Lee KJ, Jeong CK. Modulation of surface physics and chemistry in triboelectric energy harvesting technologies. SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS 2019; 20:758-773. [PMID: 31447955 PMCID: PMC6691791 DOI: 10.1080/14686996.2019.1631716] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Revised: 06/11/2019] [Accepted: 06/11/2019] [Indexed: 05/03/2023]
Abstract
Mechanical energy harvesting technology converting mechanical energy wasted in our surroundings to electrical energy has been regarded as one of the critical technologies for self-powered sensor network and Internet of Things (IoT). Although triboelectric energy harvesters based on contact electrification have attracted considerable attention due to their various advantages compared to other technologies, a further improvement of the output performance is still required for practical applications in next-generation IoT devices. In recent years, numerous studies have been carried out to enhance the output power of triboelectric energy harvesters. The previous research approaches for enhancing the triboelectric charges can be classified into three categories: i) materials type, ii) device structure, and iii) surface modification. In this review article, we focus on various mechanisms and methods through the surface modification beyond the limitations of structural parameters and materials, such as surficial texturing/patterning, functionalization, dielectric engineering, surface charge doping and 2D material processing. This perspective study is a cornerstone for establishing next-generation energy applications consisting of triboelectric energy harvesters from portable devices to power industries.
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Affiliation(s)
- Bo-Yeon Lee
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
- Department of Nature-Inspired Nano-convergence System, Korea Institute of Machinery and Materials (KIMM), Daejeon, Republic of Korea
| | - Dong Hyun Kim
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Jiseul Park
- Division of Advanced Materials Engineering, Chonbuk National University, Jeonju, Republic of Korea
| | - Kwi-Il Park
- School of Materials Science and Engineering, Kyungpook National University, Daegu, Republic of Korea
| | - Keon Jae Lee
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Chang Kyu Jeong
- Division of Advanced Materials Engineering, Chonbuk National University, Jeonju, Republic of Korea
- Hydrogen and Fuel Cell Research Center, Chonbuk National University, Jeonju, Republic of Korea
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13
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Kim DS, Yun YD, Kim JS, Kim YB, Jung SH, Deshpande NG, Lee HS, Cho HK. Electrochemically Assembled Cu 2O Nanoparticles Using Crystallographically Anisotropic Functional Metal Ions and Highly Expeditious Resistive Switching via Nanoparticle Coarsening. ACS NANO 2019; 13:5987-5998. [PMID: 31083962 DOI: 10.1021/acsnano.9b02108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We have developed an artificially controllable strategy of an electrodeposition process adequate for resistive random-access memory (ReRAM) applications of binary Cu2O. Typically, the precise control of OH- ion concentration (the intermediate supplier of oxygen ions) at the electrode's surface decides the overall reaction rate of the Cu2O. Here, the suggested Pb and Sb metal additives preferentially contribute to the consumption of OH- ions and the supply of OH- ions, respectively, during the Cu2O electrochemical reaction so that the final products are the (200) preferential quadrangular pyramids and the (111) preferential triangular pyramids. Interestingly, the coexistence of Sb/Pb precursors in the Cu electrolytes results in extraordinarily decreased reaction rate from the opposite action of OH- ion utilization as well as intense progressive growth behavior, and the resultant Cu2O films consist of crystallized small-size nanoparticles (NPs) in an amorphous-like matrix. In the case of ReRAM applications, while the polycrystalline film induces irregular device performance and the amorphous layer shows an easily irreparable electrical breakdown, our NP-assembled Cu2O films from Pb/Sb metal ions reveal the formation of a conduction bridge via phase change to a crystalline filament with no need for forming voltage and with superior electrical stability. It is attributed to the coalescence of crystal NPs into large grains during the set/reset cycle process for the heat dissipation of Joule heating. The Cu2O sample prepared with a 3 mM Sb + 3 mM Pb mixture solution exhibits forming-free ReRAM devices with high on/off resistance ratios of 1.2 × 104 and long-term electrical/thermal stability.
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Affiliation(s)
- Dong Su Kim
- School of Advanced Materials Science and Engineering , Sungkyunkwan University , 2066, Seobu-ro , Jangan-gu, Suwon-si , Gyeonggi-do 16419 , Republic of Korea
| | - Young Dae Yun
- School of Advanced Materials Science and Engineering , Sungkyunkwan University , 2066, Seobu-ro , Jangan-gu, Suwon-si , Gyeonggi-do 16419 , Republic of Korea
| | - Joo Sung Kim
- School of Advanced Materials Science and Engineering , Sungkyunkwan University , 2066, Seobu-ro , Jangan-gu, Suwon-si , Gyeonggi-do 16419 , Republic of Korea
| | - Young Been Kim
- School of Advanced Materials Science and Engineering , Sungkyunkwan University , 2066, Seobu-ro , Jangan-gu, Suwon-si , Gyeonggi-do 16419 , Republic of Korea
| | - Sung Hyeon Jung
- School of Advanced Materials Science and Engineering , Sungkyunkwan University , 2066, Seobu-ro , Jangan-gu, Suwon-si , Gyeonggi-do 16419 , Republic of Korea
| | - Nishad G Deshpande
- School of Advanced Materials Science and Engineering , Sungkyunkwan University , 2066, Seobu-ro , Jangan-gu, Suwon-si , Gyeonggi-do 16419 , Republic of Korea
| | - Ho Seong Lee
- School of Materials Science and Engineering , Kyungpook National University 80 Daehak-ro , Buk-gu, Daegu 41566 , Republic of Korea
| | - Hyung Koun Cho
- School of Advanced Materials Science and Engineering , Sungkyunkwan University , 2066, Seobu-ro , Jangan-gu, Suwon-si , Gyeonggi-do 16419 , Republic of Korea
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14
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Park WI, Choi YJ, Yuk JM, Seo HK, Kim KH. Enhanced self-assembly of block copolymers by surface modification of a guiding template. Polym J 2017. [DOI: 10.1038/s41428-017-0007-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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15
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Avila-Salas F, Pereira A, Rojas MA, Saavedra-Torres M, Montecinos R, Bonardd S, Quezada C, Saldías S, Díaz Díaz D, Leiva A, Radic D, Saldías C. An experimental and theoretical comparative study of the entrapment and release of dexamethasone from micellar and vesicular aggregates of PAMAM-PCL dendrimers. Eur Polym J 2017. [DOI: 10.1016/j.eurpolymj.2017.06.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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16
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You BK, Kim JM, Joe DJ, Yang K, Shin Y, Jung YS, Lee KJ. Reliable Memristive Switching Memory Devices Enabled by Densely Packed Silver Nanocone Arrays as Electric-Field Concentrators. ACS NANO 2016; 10:9478-9488. [PMID: 27718554 DOI: 10.1021/acsnano.6b04578] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Memristor devices based on electrochemical metallization operate through electrochemical formation/dissolution of nanoscale metallic filaments, and they are considered a promising future nonvolatile memory because of their outstanding characteristics over conventional charge-based memories. However, nanoscale conductive paths or filaments precipitated from the redox process of metallic elements are randomly formed inside oxides, resulting in unexpected and stochastic memristive switching parameters including the operating voltage and the resistance state. Here, we present the guided formation of conductive filaments in Ag nanocone/SiO2 nanomesh/Pt memristors fabricated by high-resolution nanotransfer printing. Consequently, the uniformity of the memristive switching behavior is significantly improved by the existence of electric-field concentrator arrays consisting of Ag nanocones embedded in SiO2 nanomesh structures. This selective and controlled filament growth was experimentally supported by analyzing simultaneously the surface morphology and current-mapping results using conductive atomic force microscopy. Moreover, stable multilevel switching operations with four discrete conduction states were achieved by the nanopatterned memristor device, demonstrating its potential in high-density nanoscale memory devices.
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Affiliation(s)
- Byoung Kuk You
- Department of Materials Science and Engineering and ‡Department of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Jong Min Kim
- Department of Materials Science and Engineering and ‡Department of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Daniel J Joe
- Department of Materials Science and Engineering and ‡Department of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Kyounghoon Yang
- Department of Materials Science and Engineering and ‡Department of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Youngsoo Shin
- Department of Materials Science and Engineering and ‡Department of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Yeon Sik Jung
- Department of Materials Science and Engineering and ‡Department of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Keon Jae Lee
- Department of Materials Science and Engineering and ‡Department of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
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17
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Majewski PW, Yager KG. Rapid ordering of block copolymer thin films. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2016; 28:403002. [PMID: 27537062 DOI: 10.1088/0953-8984/28/40/403002] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Block-copolymers self-assemble into diverse morphologies, where nanoscale order can be finely tuned via block architecture and processing conditions. However, the ultimate usage of these materials in real-world applications may be hampered by the extremely long thermal annealing times-hours or days-required to achieve good order. Here, we provide an overview of the fundamentals of block-copolymer self-assembly kinetics, and review the techniques that have been demonstrated to influence, and enhance, these ordering kinetics. We discuss the inherent tradeoffs between oven annealing, solvent annealing, microwave annealing, zone annealing, and other directed self-assembly methods; including an assessment of spatial and temporal characteristics. We also review both real-space and reciprocal-space analysis techniques for quantifying order in these systems.
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Affiliation(s)
- Pawel W Majewski
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY, USA. Department of Chemistry, University of Warsaw, Warsaw, Poland
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18
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Park S, Cheng X, Böker A, Tsarkova L. Hierarchical Manipulation of Block Copolymer Patterns on 3D Topographic Substrates: Beyond Graphoepitaxy. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2016; 28:6900-5. [PMID: 27270877 DOI: 10.1002/adma.201601098] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 04/25/2016] [Indexed: 05/25/2023]
Abstract
Templates of complex nanopatterns in a form of hierarchically sequenced dots and stripes can be generated in block copolymer films on lithography-free 3D topographic substrates. The approach exploits thickness- and swelling-responsive morphological behavior of block copolymers, and demonstrates novel possibilities of topography-guided registration of nanopatterns due to periodic confinement and spontaneous orthogonal flow-fields.
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Affiliation(s)
- Sungjune Park
- DWI-Leibniz-Institute für Interaktiven Materialien and Institut für Physikalische Chemie, RWTH Aachen University, Forckenbeckstraße 50, 52056, Aachen, Germany
| | - Xiao Cheng
- DWI-Leibniz-Institute für Interaktiven Materialien and Institut für Physikalische Chemie, RWTH Aachen University, Forckenbeckstraße 50, 52056, Aachen, Germany
| | - Alexander Böker
- Fraunhofer-Institut für Angewandte Polymerforschung, Lehrstuhl für Polymermaterialien und Polymertechnologie, Universität Potsdam, Geiselbergstraße 69, 14476, Potsdam-Golm, Germany
| | - Larisa Tsarkova
- DWI-Leibniz-Institute für Interaktiven Materialien and Institut für Physikalische Chemie, RWTH Aachen University, Forckenbeckstraße 50, 52056, Aachen, Germany
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19
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Zeng M, Wang L, Liu J, Zhang T, Xue H, Xiao Y, Qin Z, Fu L. Self-Assembly of Graphene Single Crystals with Uniform Size and Orientation: The First 2D Super-Ordered Structure. J Am Chem Soc 2016; 138:7812-5. [DOI: 10.1021/jacs.6b03208] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mengqi Zeng
- College of Chemistry and Molecular Science, Wuhan University, Wuhan 430072, P. R. China
| | - Lingxiang Wang
- College of Chemistry and Molecular Science, Wuhan University, Wuhan 430072, P. R. China
| | - Jinxin Liu
- College of Chemistry and Molecular Science, Wuhan University, Wuhan 430072, P. R. China
| | - Tao Zhang
- College of Chemistry and Molecular Science, Wuhan University, Wuhan 430072, P. R. China
| | - Haifeng Xue
- College of Chemistry and Molecular Science, Wuhan University, Wuhan 430072, P. R. China
| | - Yao Xiao
- College of Chemistry and Molecular Science, Wuhan University, Wuhan 430072, P. R. China
| | - Zhihui Qin
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular
Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy Sciences, Wuhan 430071, P. R. China
| | - Lei Fu
- College of Chemistry and Molecular Science, Wuhan University, Wuhan 430072, P. R. China
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20
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Peng M, Liu Y, Yu A, Zhang Y, Liu C, Liu J, Wu W, Zhang K, Shi X, Kou J, Zhai J, Wang ZL. Flexible Self-Powered GaN Ultraviolet Photoswitch with Piezo-Phototronic Effect Enhanced On/Off Ratio. ACS NANO 2016; 10:1572-9. [PMID: 26670330 DOI: 10.1021/acsnano.5b07217] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Flexible self-powered sensing is urgently needed for wearable, portable, sustainable, maintenance-free and long-term applications. Here, we developed a flexible and self-powered GaN membrane-based ultraviolet (UV) photoswitch with high on/off ratio and excellent sensitivity. Even without any power supply, the driving force of UV photogenerated carriers can be well boosted by the combination of both built-in electric field and piezoelectric polarization field. The asymmetric metal-semiconductor-metal structure has been elaborately utilized to enhance the carrier separation and transport for highly sensitive UV photoresponse. Its UV on/off ratio and detection sensitivity reach to 4.67 × 10(5) and 1.78 × 10(12) cm·Hz(0.5) W(1-), respectively. Due to its excellent mechanical flexibility, the piezoelectric polarization field in GaN membrane can be easily tuned/controlled based on piezo-phototronic effect. Under 1% strain, a stronger and broader depletion region can be obtained to further enhance UV on/off ratio up to 154%. As a result, our research can not only provide a deep understanding of local electric field effects on self-powered optoelectronic detection, but also promote the development of self-powered flexible optoelectronic devices and integrated systems.
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Affiliation(s)
- Mingzeng Peng
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences , Beijing 100083, China
| | - Yudong Liu
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences , Beijing 100083, China
| | - Aifang Yu
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences , Beijing 100083, China
| | - Yang Zhang
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences , Beijing 100083, China
| | - Caihong Liu
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences , Beijing 100083, China
| | - Jingyu Liu
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences , Beijing 100083, China
| | - Wei Wu
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences , Beijing 100083, China
| | - Ke Zhang
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences , Beijing 100083, China
| | - Xieqing Shi
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences , Beijing 100083, China
| | - Jinzong Kou
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences , Beijing 100083, China
| | - Junyi Zhai
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences , Beijing 100083, China
| | - Zhong Lin Wang
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences , Beijing 100083, China
- School of Materials Science and Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332-0245, United States
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21
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Wu ML, Wang D. Microdomain orientation control of PS-b-PMMA films enabled by wettability relay of graphene. RSC Adv 2016. [DOI: 10.1039/c5ra24953h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
A substrate-independent method to control the orientation of PS-b-PMMA film is presented by utilizing monolayer graphene coated PS-r-PMMA copolymer layer.
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Affiliation(s)
- Mei-Ling Wu
- Key Laboratory of Molecular Nanostructure and Nanotechnology and Beijing National Laboratory for Molecular Sciences
- Institute of Chemistry
- Chinese Academy of Sciences (CAS)
- Beijing 100190
- P. R. China
| | - Dong Wang
- Key Laboratory of Molecular Nanostructure and Nanotechnology and Beijing National Laboratory for Molecular Sciences
- Institute of Chemistry
- Chinese Academy of Sciences (CAS)
- Beijing 100190
- P. R. China
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22
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Park KI, Jeong CK, Kim NK, Lee KJ. Stretchable piezoelectric nanocomposite generator. NANO CONVERGENCE 2016; 3:12. [PMID: 28191422 PMCID: PMC5271155 DOI: 10.1186/s40580-016-0072-z] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 04/12/2016] [Indexed: 05/17/2023]
Abstract
Piezoelectric energy conversion that generate electric energy from ambient mechanical and vibrational movements is promising energy harvesting technology because it can use more accessible energy resources than other renewable natural energy. In particular, flexible and stretchable piezoelectric energy harvesters which can harvest the tiny biomechanical motions inside human body into electricity properly facilitate not only the self-powered energy system for flexible and wearable electronics but also sensitive piezoelectric sensors for motion detectors and in vivo diagnosis kits. Since the piezoelectric ZnO nanowires (NWs)-based energy harvesters (nanogenerators) were proposed in 2006, many researchers have attempted the nanogenerator by using the various fabrication process such as nanowire growth, electrospinning, and transfer techniques with piezoelectric materials including polyvinylidene fluoride (PVDF) polymer and perovskite ceramics. In 2012, the composite-based nanogenerators were developed using simple, low-cost, and scalable methods to overcome the significant issues with previously-reported energy harvester, such as insufficient output performance and size limitation. This review paper provides a brief overview of flexible and stretchable piezoelectric nanocomposite generator for realizing the self-powered energy system with development history, power performance, and applications.
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Affiliation(s)
- Kwi-Il Park
- Department of Energy Engineering, Gyeongnam National University of Science and Technology (GNTECH), 33 Dongjin-ro, Jinju-si, Gyeongsangnam-do 52725 Republic of Korea
| | - Chang Kyu Jeong
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
- KAIST Institute for the NanoCentury (KINC), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Na Kyung Kim
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Keon Jae Lee
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
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23
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Park S, Park D, Jeong K, Kim T, Park S, Ahn M, Yang WJ, Han JH, Jeong HS, Jeon SG, Song JY, Cho MH. Effect of the Thermal Conductivity on Resistive Switching in GeTe and Ge2Sb2Te5 Nanowires. ACS APPLIED MATERIALS & INTERFACES 2015; 7:21819-21827. [PMID: 26369988 DOI: 10.1021/acsami.5b05703] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The thermal conduction characteristics of GeTe and Ge2Sb2Te5(GST) nanowires were investigated using an optical method to determine the local temperature by Raman spectroscopy. Since the localization of surface charge in a single-crystalline nanostructure can enhance charge-phonon scattering, the thermal conductivity value (κ) of single crystalline GeTe and GST nanowires was decreased significantly to 1.44 Wm(-1) K(-1) for GeTe and 1.13 Wm(-1) K(-1) for GST, compared to reported values for polycrystalline structures. The SET-to-RESET state in single-crystalline GeTe and GST nanowires are characteristic of a memory device. Unlike previous reports using GeTe and GST nanowires, the SET-to-RESET characteristics showed a bipolar switching shape and no unipolar switching. In addition, after multiple cycles of operation, a significant change in morphology and composition was observed without any structural phase transition, indicating that atoms migrate toward the cathode or anode, depending on their electronegativities. This change caused by a field effect indicates that the structural phase transition does not occur in the case of GeTe and GST nanowires with a significantly lowered thermal conductivity and stable crystalline structure. Finally, the formation of voids and hillocks as the result of the electromigration critically degrades device reliability.
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Affiliation(s)
- Sungjin Park
- Institute of Physics and Applied Physics, Yonsei University , Seoul, 120-749 Korea
| | - Dambi Park
- Institute of Physics and Applied Physics, Yonsei University , Seoul, 120-749 Korea
| | - Kwangsik Jeong
- Institute of Physics and Applied Physics, Yonsei University , Seoul, 120-749 Korea
| | - Taeok Kim
- Institute of Physics and Applied Physics, Yonsei University , Seoul, 120-749 Korea
| | - SeungJong Park
- Institute of Physics and Applied Physics, Yonsei University , Seoul, 120-749 Korea
| | - Min Ahn
- Institute of Physics and Applied Physics, Yonsei University , Seoul, 120-749 Korea
| | - Won Jun Yang
- Institute of Physics and Applied Physics, Yonsei University , Seoul, 120-749 Korea
| | - Jeong Hwa Han
- Institute of Physics and Applied Physics, Yonsei University , Seoul, 120-749 Korea
| | - Hong Sik Jeong
- School of Integrated Technology, Yonsei University , Incheon, 406-840 Korea
| | - Seong Gi Jeon
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology , Daejeon 305-701, Republic of Korea
| | - Jae Yong Song
- Korea Research Institute of Standards and Science , Daejeon 305-340, Republic of Korea
| | - Mann-Ho Cho
- Institute of Physics and Applied Physics, Yonsei University , Seoul, 120-749 Korea
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24
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Yoo HG, Byun M, Jeong CK, Lee KJ. Performance Enhancement of Electronic and Energy Devices via Block Copolymer Self-Assembly. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2015; 27:3982-98. [PMID: 26061137 DOI: 10.1002/adma.201501592] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Revised: 05/04/2015] [Indexed: 05/23/2023]
Abstract
The use of self-assembled block copolymers (BCPs) for the fabrication of electronic and energy devices has received a tremendous amount of attention as a non-traditional approach to patterning integrated circuit elements at nanometer dimensions and densities inaccessible to traditional lithography techniques. The exquisite control over the dimensional features of the self-assembled nanostructures (i.e., shape, size, and periodicity) is one of the most attractive properties of BCP self-assembly. Harmonic spatial arrangement of the self-assembled nanoelements at desired positions on the chip may offer a new strategy for the fabrication of electronic and energy devices. Several recent reports show the great promise in using BCP self-assembly for practical applications of electronic and energy devices, leading to substantial enhancements of the device performance. Recent progress is summarized here, with regard to the performance enhancements of non-volatile memory, electrical sensor, and energy devices enabled by directed BCP self-assembly.
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Affiliation(s)
- Hyeon Gyun Yoo
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701, Republic of Korea
| | - Myunghwan Byun
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701, Republic of Korea
| | - Chang Kyu Jeong
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701, Republic of Korea
| | - Keon Jae Lee
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701, Republic of Korea
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25
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You BK, Byun M, Kim S, Lee KJ. Self-Structured Conductive Filament Nanoheater for Chalcogenide Phase Transition. ACS NANO 2015; 9:6587-6594. [PMID: 26039415 DOI: 10.1021/acsnano.5b02579] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Ge2Sb2Te5-based phase-change memories (PCMs), which undergo fast and reversible switching between amorphous and crystalline structural transformation, are being utilized for nonvolatile data storage. However, a critical obstacle is the high programming current of the PCM cell, resulting from the limited pattern size of the optical lithography-based heater. Here, we suggest a facile and scalable strategy of utilizing self-structured conductive filament (CF) nanoheaters for Joule heating of chalcogenide materials. This CF nanoheater can replace the lithographical-patterned conventional resistor-type heater. The sub-10 nm contact area between the CF and the phase-change material achieves significant reduction of the reset current. In particular, the PCM cell with a single Ni filament nanoheater can be operated at an ultralow writing current of 20 μA. Finally, phase-transition behaviors through filament-type nanoheaters were directly observed by using transmission electron microscopy.
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Affiliation(s)
- Byoung Kuk You
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea
| | - Myunghwan Byun
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea
| | - Seungjun Kim
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea
| | - Keon Jae Lee
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea
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26
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Mun BH, You BK, Yang SR, Yoo HG, Kim JM, Park WI, Yin Y, Byun M, Jung YS, Lee KJ. Flexible one diode-one phase change memory array enabled by block copolymer self-assembly. ACS NANO 2015; 9:4120-4128. [PMID: 25826001 DOI: 10.1021/acsnano.5b00230] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Flexible memory is the fundamental component for data processing, storage, and radio frequency communication in flexible electronic systems. Among several emerging memory technologies, phase-change random-access memory (PRAM) is one of the strongest candidate for next-generation nonvolatile memories due to its remarkable merits of large cycling endurance, high speed, and excellent scalability. Although there are a few approaches for flexible phase-change memory (PCM), high reset current is the biggest obstacle for the practical operation of flexible PCM devices. In this paper, we report a flexible PCM realized by incorporating nanoinsulators derived from a Si-containing block copolymer (BCP) to significantly lower the operating current of the flexible memory formed on plastic substrate. The reduction of thermal stress by BCP nanostructures enables the reliable operation of flexible PCM devices integrated with ultrathin flexible diodes during more than 100 switching cycles and 1000 bending cycles.
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Affiliation(s)
- Beom Ho Mun
- †Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea
| | - Byoung Kuk You
- †Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea
| | - Se Ryeun Yang
- †Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea
| | - Hyeon Gyun Yoo
- †Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea
| | - Jong Min Kim
- †Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea
| | - Woon Ik Park
- †Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea
| | - You Yin
- ‡Graduate School of Engineering, Gunma University, 1-5-1 Tenjin, Kiryu, Gunma 376-8515, Japan
| | - Myunghwan Byun
- †Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea
| | - Yeon Sik Jung
- †Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea
| | - Keon Jae Lee
- †Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea
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27
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Frascaroli J, Brivio S, Ferrarese Lupi F, Seguini G, Boarino L, Perego M, Spiga S. Resistive switching in high-density nanodevices fabricated by block copolymer self-assembly. ACS NANO 2015; 9:2518-2529. [PMID: 25743480 DOI: 10.1021/nn505131b] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Bipolar resistive switching memories based on metal oxides offer a great potential in terms of simple process integration, memory performance, and scalability. In view of ultrahigh density memory applications, a reduced device size is not the only requirement, as the distance between different devices is a key parameter. By exploiting a bottom-up fabrication approach based on block copolymer self-assembling, we obtained the parallel production of bilayer Pt/Ti top electrodes arranged in periodic arrays over the HfO2/TiN surface, building memory devices with a diameter of 28 nm and a density of 5 × 10(10) devices/cm(2). For an electrical characterization, the sharp conducting tip of an atomic force microscope was adopted for a selective addressing of the nanodevices. The presence of devices showing high conductance in the initial state was directly connected with scattered leakage current paths in the bare oxide film, while with bipolar voltage operations we obtained reversible set/reset transitions irrespective of the conductance variability in the initial state. Finally, we disclosed a scalability limit for ultrahigh density memory arrays based on continuous HfO2 thin films, in which a cross-talk between distinct nanodevices can occur during both set and reset transitions.
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Affiliation(s)
- Jacopo Frascaroli
- †Laboratorio MDM, IMM-CNR, Via C. Olivetti 2, 20864 Agrate Brianza (MB), Italy
- ‡INRiM, NanoFacility, Electromagnetism Division, Strada delle Cacce 91, 10135 Torino, Italy
- §Department of Physics, University of Milan, Via Celoria 16, 20133 Milano, Italy
| | - Stefano Brivio
- †Laboratorio MDM, IMM-CNR, Via C. Olivetti 2, 20864 Agrate Brianza (MB), Italy
| | | | - Gabriele Seguini
- †Laboratorio MDM, IMM-CNR, Via C. Olivetti 2, 20864 Agrate Brianza (MB), Italy
| | - Luca Boarino
- ‡INRiM, NanoFacility, Electromagnetism Division, Strada delle Cacce 91, 10135 Torino, Italy
| | - Michele Perego
- †Laboratorio MDM, IMM-CNR, Via C. Olivetti 2, 20864 Agrate Brianza (MB), Italy
| | - Sabina Spiga
- †Laboratorio MDM, IMM-CNR, Via C. Olivetti 2, 20864 Agrate Brianza (MB), Italy
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28
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Wang Y, Mi H, Zheng Q, Ma Z, Gong S. Graphene/phase change material nanocomposites: light-driven, reversible electrical resistivity regulation via form-stable phase transitions. ACS APPLIED MATERIALS & INTERFACES 2015; 7:2641-2647. [PMID: 25588062 DOI: 10.1021/am507700r] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Innovative photoresponsive materials are needed to address the complexity of optical control systems. Here, we report a new type of photoresponsive nanomaterial composed of graphene and a form-stable phase change material (PCM) that exhibited a 3 orders of magnitude change in electrical resistivity upon light illumination while retaining its overall original solid form at the macroscopic level. This dramatic change in electrical resistivity also occurred reversibly through the on/off control of light illumination. This was attributed to the reversible phase transition (i.e., melting/recrystallization) behavior of the microscopic crystalline domains present in the form-stable PCM. The reversible phase transition observed in the graphene/PCM nanocomposite was induced by a reversible temperature change through the on/off control of light illumination because graphene can effectively absorb light energy and convert it to thermal energy. In addition, this graphene/PCM nanocomposite also possessed excellent mechanical properties. Such photoresponsive materials have many potential applications, including flexible electronics.
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Affiliation(s)
- Yunming Wang
- Department of Biomedical Engineering, Wisconsin Institute for Discovery, and Materials Science Program, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
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29
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Jeong CK, Baek KM, Niu S, Nam TW, Hur YH, Park DY, Hwang GT, Byun M, Wang ZL, Jung YS, Lee KJ. Topographically-designed triboelectric nanogenerator via block copolymer self-assembly. NANO LETTERS 2014; 14:7031-8. [PMID: 25393064 DOI: 10.1021/nl503402c] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Herein, we report a facile and robust route to nanoscale tunable triboelectric energy harvesters realized by the formation of highly functional and controllable nanostructures via block copolymer (BCP) self-assembly. Our strategy is based on the incorporation of various silica nanostructures derived from the self-assembly of BCPs to enhance the characteristics of triboelectric nanogenerators (TENGs) by modulating the contact-surface area and the frictional force. Our simulation data also confirm that the nanoarchitectured morphologies are effective for triboelectric generation.
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Affiliation(s)
- Chang Kyu Jeong
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701, Republic of Korea
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30
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You BK, Park WI, Kim JM, Park KI, Seo HK, Lee JY, Jung YS, Lee KJ. Reliable control of filament formation in resistive memories by self-assembled nanoinsulators derived from a block copolymer. ACS NANO 2014; 8:9492-9502. [PMID: 25192434 DOI: 10.1021/nn503713f] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Resistive random access memory (ReRAM) is a promising candidate for future nonvolatile memories. Resistive switching in a metal-insulator-metal structure is generally assumed to be caused by the formation/rupture of nanoscale conductive filaments (CFs) under an applied electric field. The critical issue of ReRAM for practical memory applications, however, is insufficient repeatability of the operating voltage and resistance ratio. Here, we present an innovative approach to reliably and reproducibly control the CF growth in unipolar NiO resistive memory by exploiting uniform formation of insulating SiOx nanostructures from the self-assembly of a Si-containing block copolymer. In this way, the standard deviation (SD) of set and reset voltages was markedly reduced by 76.9% and 59.4%, respectively. The SD of high resistance state also decreased significantly, from 6.3 × 10(7) Ω to 5.4 × 10(4) Ω. Moreover, we report direct observations of localized metallic Ni CF formation and their controllable growth using electron microscopy and discuss electrothermal simulation results based on the finite element method supporting our analysis results.
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Affiliation(s)
- Byoung Kuk You
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea
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31
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Huang YT, Huang CW, Chen JY, Ting YH, Lu KC, Chueh YL, Wu WW. Dynamic observation of phase transformation behaviors in indium(III) selenide nanowire based phase change memory. ACS NANO 2014; 8:9457-9462. [PMID: 25133955 DOI: 10.1021/nn503576x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Phase change random access memory (PCRAM) has been extensively investigated for its potential applications in next-generation nonvolatile memory. In this study, indium(III) selenide (In2Se3) was selected due to its high resistivity ratio and lower programming current. Au/In2Se3-nanowire/Au phase change memory devices were fabricated and measured systematically in an in situ transmission electron microscope to perform a RESET/SET process under pulsed and dc voltage swept mode, respectively. During the switching, we observed the dynamic evolution of the phase transformation process. The switching behavior resulted from crystalline/amorphous change and revealed that a long pulse width would induce the amorphous or polycrystalline state by different pulse amplitudes, supporting the improvement of the writing speed, retention, and endurance of PCRAM.
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Affiliation(s)
- Yu-Ting Huang
- Department of Materials Science and Engineering, National Chiao Tung University , No. 1001, University Road, Hsinchu 300, Taiwan
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32
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Hosaka S, Akahane T, Huda M, Zhang H, Yin Y. Controlling of 6 nm sized and 10 nm pitched dot arrays ordered along narrow guide lines using PS-PDMS self-assembly. ACS APPLIED MATERIALS & INTERFACES 2014; 6:6208-6211. [PMID: 24761797 DOI: 10.1021/am501230d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We have studied graphoepitaxy to make nanodots or nanolines ordered along electron beam (EB)-drawn resist guide using block copolymers (BCPs) of polystyrene-polydimethylsiloxane (PS-PDMS). We found out that the number n of ordered molecular dot arrays in the line gap increases stepwise with the gap between guide lines. The n self-assembled dot arrays were ordered in a gap between n and n+1 times the mean PDMS pitch and self-assembled with no guide pattern. According to the ordering characteristics, 6 nm sized and 10 nm pitched PDMS dot arrays were formed using the BCP self-assembly with the guide lines.
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Affiliation(s)
- Sumio Hosaka
- Graduate School of Engineering, Gunma University 1-5-1 Tenjin-cho, Kiryu 376-8515, Japan
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33
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Jin C, Murphy JN, Harris KD, Buriak JM. Deconvoluting the mechanism of microwave annealing of block copolymer thin films. ACS NANO 2014; 8:3979-3991. [PMID: 24655292 DOI: 10.1021/nn5009098] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The self-assembly of block copolymer (BCP) thin films is a versatile method for producing periodic nanoscale patterns with a variety of shapes. The key to attaining a desired pattern or structure is the annealing step undertaken to facilitate the reorganization of nanoscale phase-segregated domains of the BCP on a surface. Annealing BCPs on silicon substrates using a microwave oven has been shown to be very fast (seconds to minutes), both with and without contributions from solvent vapor. The mechanism of the microwave annealing process remains, however, unclear. This work endeavors to uncover the key steps that take place during microwave annealing, which enable the self-assembly process to proceed. Through the use of in situ temperature monitoring with a fiber optic temperature probe in direct contact with the sample, we have demonstrated that the silicon substrate on which the BCP film is cast is the dominant source of heating if the doping of the silicon wafer is sufficiently low. Surface temperatures as high as 240 °C are reached in under 1 min for lightly doped, high resistivity silicon wafers (n- or p-type). The influence of doping, sample size, and BCP composition was analyzed to rule out other possible mechanisms. In situ temperature monitoring of various polymer samples (PS, P2VP, PMMA, and the BCPs used here) showed that the polymers do not heat to any significant extent on their own with microwave irradiation of this frequency (2.45 GHz) and power (∼600 W). It was demonstrated that BCP annealing can be effectively carried out in 60 s on non-microwave-responsive substrates, such as highly doped silicon, indium tin oxide (ITO)-coated glass, glass, and Kapton, by placing a piece of high resistivity silicon wafer in contact with the sample-in this configuration, the silicon wafer is termed the heating element. Annealing and self-assembly of polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP) and polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) BCPs into horizontal cylinder structures were shown to take place in under 1 min, using a silicon wafer heating element, in a household microwave oven. Defect densities were calculated and were shown to decrease with higher maximum obtained temperatures. Conflicting results in the literature regarding BCP annealing with microwave are explained in light of the results obtained in this study.
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Affiliation(s)
- Cong Jin
- National Institute for Nanotechnology , 11421 Saskatchewan Drive, Edmonton, Alberta T6G 2M9, Canada
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34
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Yoo HG, Kim S, Lee KJ. Flexible one diode–one resistor resistive switching memory arrays on plastic substrates. RSC Adv 2014. [DOI: 10.1039/c4ra02536a] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Flexible one diode–one resistor resistive random access memory (RRAM) with 8 × 8 arrays composed of high-performance silicon diodes and a resistive change material for fully functional flexible memory operation.
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Affiliation(s)
- Hyeon Gyun Yoo
- Department of Materials Science and Engineering
- Korea Advanced Institute of Science and Technology (KAIST)
- Daejeon 305-701, Republic of Korea
| | - Seungjun Kim
- Department of Materials Science and Engineering
- Korea Advanced Institute of Science and Technology (KAIST)
- Daejeon 305-701, Republic of Korea
| | - Keon Jae Lee
- Department of Materials Science and Engineering
- Korea Advanced Institute of Science and Technology (KAIST)
- Daejeon 305-701, Republic of Korea
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35
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Wu NLY, Harris KD, Buriak JM. Conversion of bilayers of PS-b-PDMS block copolymer into closely packed, aligned silica nanopatterns. ACS NANO 2013; 7:5595-5606. [PMID: 23675942 DOI: 10.1021/nn401968t] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Block copolymer (BCP) self-assembly is an effective and versatile approach for the production of complex nanopatterned interfaces. Monolayers of BCP films can be harnessed to produce a variety of different patterns, including lines, with specific spacings and order. In this work, bilayers of cylinder-forming polystyrene-block-polydimethylsiloxane block copolymer (PS-b-PDMS) were transformed into arrays of silica lines with half the pitch normally attained for conventional monolayers, with the PDMS acting as the source for the SiOx. The primary hurdle was ensuring the bilayer silica lines were distinctly separate; to attain the control necessary to prevent overlap, a number of variables related to the materials and self-assembly process were investigated in detail. Developing a detailed understanding of BCP film swelling during solvent annealing, blending of the PS-b-PDMS with PS homopolymer, utilization of a surface brush layer, and adjustment of the plasma exposure conditions, distinct and separate silica lines were prepared. On the microscale, the sample coverage of PS-b-PDMS bilayers was investigated and maximized to attain >95% bilayers under defined conditions. The bilayer BCP structures were also amenable to graphoepitaxy, and thus, dense and highly ordered arrays of silica line patterns with tightly controlled width and pitch were fabricated and distributed uniformly across a Si surface.
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Affiliation(s)
- Nathanael L Y Wu
- National Institute for Nanotechnology (NINT), National Research Council, 11421 Saskatchewan Drive, Edmonton, Alberta T6G 2M9, Canada
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