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Structures, Electronic Properties and Carrier Transport Mechanisms of Si Nano-Crystalline Embedded in the Amorphous SiC Films with Various Si/C Ratios. NANOMATERIALS 2021; 11:nano11102678. [PMID: 34685119 PMCID: PMC8538480 DOI: 10.3390/nano11102678] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Revised: 10/08/2021] [Accepted: 10/09/2021] [Indexed: 11/17/2022]
Abstract
Recent investigations of fundamental electronic properties (especially the carrier transport mechanisms) of Si nanocrystal embedded in the amorphous SiC films are highly desired in order to further develop their applications in nano-electronic and optoelectronic devices. Here, Boron-doped Si nanocrystals embedded in the amorphous SiC films were prepared by thermal annealing of Boron-doped amorphous Si-rich SiC films with various Si/C ratios. Carrier transport properties in combination with microstructural characteristics were investigated via temperature dependence Hall effect measurements. It should be pointed out that Hall mobilities, carrier concentrations as well as conductivities in films were increased with Si/C ratio, which could be reached to the maximum of 7.2 cm2/V∙s, 4.6 × 1019 cm−3 and 87.5 S∙cm−1, respectively. Notably, different kinds of carrier transport behaviors, such as Mott variable-range hopping, multiple phonon hopping, percolation hopping and thermally activation conduction that play an important role in the transport process, were identified within different temperature ranges (10 K~400 K) in the films of different Si/C ratio. The changes from Mott variable-range hopping process to thermally activation conduction process with temperature were observed and discussed in detail.
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Zeng T, Zou X, Wang Z, Yu G, Yang Z, Rong H, Zhang C, Xu H, Lin Y, Zhao X, Ma J, Zhu G, Liu Y. Zeolite-Based Memristive Synapse with Ultralow Sub-10-fJ Energy Consumption for Neuromorphic Computation. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2006662. [PMID: 33738968 DOI: 10.1002/smll.202006662] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Revised: 01/08/2021] [Indexed: 06/12/2023]
Abstract
The development of neuromorphic computation faces the appreciable challenge of implementing hardware with energy consumption on the level of a femtojoule per synaptic event to be comparable with the energy consumption of human brain. Controllable ultrathin conductive filaments are needed to achieve such extremely low energy consumption in memristive synapses but their formation is difficult to control owing to their stochastic morphology and unexpected overgrowth. Herein, a zeolite-based memristive synapse is demonstrated for the first time, in which Ag exchange in the sub-nanometer pore closely resembles synaptic Ca2+ dynamics across biomembrane channel. Particularly, the confined ultrasmall pore and low Ag ion migration barrier give the zeolite-based memristive synapse ultralow energy consumption below 10 fJ per synaptic spike, on par with the biological counterpart. Experimental results reveal that the gradual memristive effect is attributed to the dimension modulation of Ag clusters. In addition to emulating inherent cognitive functions through electrical stimulations, the experience-dependent transition of short-term plasticity to long-term plasticity using a chemical modulation method is achieved by treating the initial Ag quantity as a learning experience. The proposed memristors can be used to develop highly efficient memristive neural networks and are considered as a candidate for application in neuromorphic computation.
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Affiliation(s)
- Tao Zeng
- Key Laboratory for UV Light-Emitting Materials and Technology (Northeast Normal University), Ministry of Education, 5268 Renmin Street, Changchun, 130024, P. R. China
| | - Xiaoqin Zou
- Faculty of Chemistry, Northeast Normal University, 5268 Renmin Street, Changchun, 130024, P. R. China
| | - Zhongqiang Wang
- Key Laboratory for UV Light-Emitting Materials and Technology (Northeast Normal University), Ministry of Education, 5268 Renmin Street, Changchun, 130024, P. R. China
| | - Guangli Yu
- Faculty of Chemistry, Northeast Normal University, 5268 Renmin Street, Changchun, 130024, P. R. China
| | - Zhi Yang
- Key Laboratory for UV Light-Emitting Materials and Technology (Northeast Normal University), Ministry of Education, 5268 Renmin Street, Changchun, 130024, P. R. China
| | - Huazhen Rong
- Faculty of Chemistry, Northeast Normal University, 5268 Renmin Street, Changchun, 130024, P. R. China
| | - Chi Zhang
- Faculty of Chemistry, Northeast Normal University, 5268 Renmin Street, Changchun, 130024, P. R. China
| | - Haiyang Xu
- Key Laboratory for UV Light-Emitting Materials and Technology (Northeast Normal University), Ministry of Education, 5268 Renmin Street, Changchun, 130024, P. R. China
| | - Ya Lin
- Key Laboratory for UV Light-Emitting Materials and Technology (Northeast Normal University), Ministry of Education, 5268 Renmin Street, Changchun, 130024, P. R. China
| | - Xiaoning Zhao
- Key Laboratory for UV Light-Emitting Materials and Technology (Northeast Normal University), Ministry of Education, 5268 Renmin Street, Changchun, 130024, P. R. China
| | - Jiangang Ma
- Key Laboratory for UV Light-Emitting Materials and Technology (Northeast Normal University), Ministry of Education, 5268 Renmin Street, Changchun, 130024, P. R. China
| | - Guangshan Zhu
- Faculty of Chemistry, Northeast Normal University, 5268 Renmin Street, Changchun, 130024, P. R. China
| | - Yichun Liu
- Key Laboratory for UV Light-Emitting Materials and Technology (Northeast Normal University), Ministry of Education, 5268 Renmin Street, Changchun, 130024, P. R. China
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Kesavan AV, Lee BR, Son KR, Khot AC, Dongale TD, Murugadoss V, Ramamurthy PC, Kim TG. Work Function-Tunable Amorphous Carbon-Silver Nanocomposite Hybrid Electrode for Optoelectronic Applications. ACS APPLIED MATERIALS & INTERFACES 2021; 13:4284-4293. [PMID: 33433998 DOI: 10.1021/acsami.0c13937] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Parameters such as electrode work function (WF), optical reflectance, electrode morphology, and interface roughness play a crucial role in optoelectronic device design; therefore, fine-tuning these parameters is essential for efficient end-user applications. In this study, amorphous carbon-silver (C-Ag) nanocomposite hybrid electrodes are proposed and fully characterized for solar photovoltaic applications. Basically, the WF, sheet resistance, and optical reflectance of the C-Ag nanocomposite electrode are fine-tuned by varying the composition in a wide range. Experimental results suggest that irrespective of the variation in the graphite-silver composition, smaller and consistent grain size distributions offer uniform WF across the electrode surface. In addition, the strong C-Ag interaction in the nanocomposite enhances the nanomechanical properties of the hybrid electrode, such as hardness, reduced modulus, and elastic recovery parameters. Furthermore, the C-Ag nanocomposite hybrid electrode exhibits relatively lower surface roughness than the commercially available carbon paste electrode. These results suggest that the C-Ag nanocomposite electrode can be used for highly efficient photovoltaics in place of the conventional carbon-based electrodes.
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Affiliation(s)
- Arul Varman Kesavan
- School of Electrical Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Byeong Ryong Lee
- School of Electrical Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Kyung Rock Son
- School of Electrical Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Atul C Khot
- School of Electrical Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Tukaram D Dongale
- School of Electrical Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
- School of Nanoscience and Biotechnology, Shivaji University, Kolhapur 416 004, India
| | - Vignesh Murugadoss
- School of Electrical Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Praveen C Ramamurthy
- Department of Materials Engineering, Indian Institute of Science, Bangalore 560012, India
| | - Tae Geun Kim
- School of Electrical Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
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Qian M, Shan D, Ji Y, Li D, Xu J, Li W, Chen K. Transition of Carrier Transport Behaviors with Temperature in Phosphorus-Doped Si Nanocrystals/SiO2 Multilayers. NANOSCALE RESEARCH LETTERS 2016; 11:346. [PMID: 27460594 PMCID: PMC4961652 DOI: 10.1186/s11671-016-1561-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 07/21/2016] [Indexed: 05/17/2023]
Abstract
High-conductive phosphorus-doped Si nanocrystals/SiO2(nc-Si/SiO2) multilayers are obtained, and the formation of Si nanocrystals with the average crystal size of 6 nm is confirmed by high-resolution transmission electron microscopy and Raman spectra. The temperature-dependent carrier transport behaviors of the nc-Si/SiO2 films are systematically studied by which we find the shift of Fermi level on account of the changing P doping concentration. By controlling the P doping concentration in the films, the room temperature conductivity can be enhanced by seven orders of magnitude than the un-doped sample, reaching values up to 110 S/cm for heavily doped sample. The changes from Mott variable-range hopping process to thermally activation conduction process with the temperature are identified and discussed.
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Affiliation(s)
- Mingqing Qian
- National Laboratory of Solid State Microstructures, School of Electronic Science and Engineering and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Hankou Road 22, Nanjing City, Jiangsu Province 210093 China
| | - Dan Shan
- National Laboratory of Solid State Microstructures, School of Electronic Science and Engineering and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Hankou Road 22, Nanjing City, Jiangsu Province 210093 China
| | - Yang Ji
- National Laboratory of Solid State Microstructures, School of Electronic Science and Engineering and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Hankou Road 22, Nanjing City, Jiangsu Province 210093 China
| | - Dongke Li
- National Laboratory of Solid State Microstructures, School of Electronic Science and Engineering and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Hankou Road 22, Nanjing City, Jiangsu Province 210093 China
| | - Jun Xu
- National Laboratory of Solid State Microstructures, School of Electronic Science and Engineering and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Hankou Road 22, Nanjing City, Jiangsu Province 210093 China
| | - Wei Li
- National Laboratory of Solid State Microstructures, School of Electronic Science and Engineering and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Hankou Road 22, Nanjing City, Jiangsu Province 210093 China
| | - Kunji Chen
- National Laboratory of Solid State Microstructures, School of Electronic Science and Engineering and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Hankou Road 22, Nanjing City, Jiangsu Province 210093 China
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Keller BD, Ferralis N, Grossman JC. Rethinking Coal: Thin Films of Solution Processed Natural Carbon Nanoparticles for Electronic Devices. NANO LETTERS 2016; 16:2951-2957. [PMID: 27031328 DOI: 10.1021/acs.nanolett.5b04735] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Disordered carbon materials, both amorphous and with long-range order, have been used in a variety of applications, from conductive additives and contact materials to transistors and photovoltaics. Here we show a flexible solution-based method of preparing thin films with tunable electrical properties from suspensions of ball-milled coals following centrifugation. The as-prepared films retain the rich carbon chemistry of the starting coals with conductivities ranging over orders of magnitude, and thermal treatment of the resulting films further tunes the electrical conductivity in excess of 7 orders of magnitude. Optical absorption measurements demonstrate tunable optical gaps from 0 to 1.8 eV. Through low-temperature conductivity measurements and Raman spectroscopy, we demonstrate that variable range hopping controls the electrical properties in as-prepared and thermally treated films and that annealing increases the sp(2) content, localization length, and disorder. The measured hopping energies demonstrate electronic properties similar to amorphous carbon materials and reduced graphene oxide. Finally, Joule heating devices were fabricated from coal-based films, and temperatures as high as 285 °C with excellent stability were achieved.
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Affiliation(s)
- Brent D Keller
- Department of Materials Science and Engineering, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Nicola Ferralis
- Department of Materials Science and Engineering, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Jeffrey C Grossman
- Department of Materials Science and Engineering, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
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Raj KG, Joy PA. Cross over from 3D variable range hopping to the 2D weak localization conduction mechanism in disordered carbon with the extent of graphitization. Phys Chem Chem Phys 2015; 17:16178-85. [DOI: 10.1039/c5cp00329f] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The changes in the conduction mechanism in disordered carbon upon graphitization with increasing heat treatment temperature (HTT) are reported.
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Affiliation(s)
- Kovummal Govind Raj
- Physical and Materials Chemistry Division
- CSIR-National Chemical Laboratory
- Pune 411008
- India
- Academy of Scientific and Innovative Research
| | - Pattayil Alias Joy
- Physical and Materials Chemistry Division
- CSIR-National Chemical Laboratory
- Pune 411008
- India
- Academy of Scientific and Innovative Research
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Affiliation(s)
- C. Godet
- a Laboratoire de Physique des Interfaces et des Couches Minces, Unité Mixte de Recherche 7647 CNRS-Ecole Polytechnique , 91128 , Palaiseau Cedex , France
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Han ZJ, Tay BK. Electrical conductivity of poly(ethylene terephthalate) modified by titanium plasma. J Appl Polym Sci 2007. [DOI: 10.1002/app.27414] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Ito K, Tanabe Y, Akagi K, Shirakawa H. Complex conductivity of polyacetylene films prepared by different methods. PHYSICAL REVIEW. B, CONDENSED MATTER 1992; 45:1246-1254. [PMID: 10001601 DOI: 10.1103/physrevb.45.1246] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Varga I, Pipek J. Localization properties of the nonbonding pi states at the Fermi level in amorphous carbon. PHYSICAL REVIEW. B, CONDENSED MATTER 1990; 42:5335-5338. [PMID: 9996102 DOI: 10.1103/physrevb.42.5335] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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