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Xia S, Diao Y, Jiang M, Kan C. Photocurrent enhancement of Al xGa 1-xN nanowire arrays photodetector based on coupling effects of pn junction and gradient component. NANOTECHNOLOGY 2021; 32:385708. [PMID: 34102620 DOI: 10.1088/1361-6528/ac0933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Accepted: 06/08/2021] [Indexed: 06/12/2023]
Abstract
Ultraviolet photodetector has a variety of applications in medical diagnosis, civilian testing and military security. The enhancement of photo response has far been a hot topic regrading to the performance improvement of the devices. In this study, we proposed a self-powered photodetector based on AlxGa1-xN nanowire arrays (NWAs) utilizing axial pn junction integrating with gradient Al component. The merit of the coupling structure is demonstrated by theoretical model and simulations. The photoelectric conversion model is built based on a continuity equation derived by its corresponding boundary conditions. The photocurrent for a single nanowire and NWAs are respectively obtained. According to the simulation results of a single nanowire, the optimal nanowire height is obtained with a photocurrent enhancement up to 330%. For NWAs, the aspect ratio of NWAs and incident angle of light synergistically determine the output photocurrent. The optimal aspect ratio for NWAs is 1:1 with an optimal incident angle of 57°. This study provides a reliable method for the design of photodetectors with micro-nano structures.
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Affiliation(s)
- Sihao Xia
- College of Science, Nanjing University of Aeronautics & Astronautics, No. 29 Jiangjun Rd, Nanjing 211106, People's Republic of China
- Key Lab Intelligent Nano Materials & Devices, Nanjing University of Aeronautics & Astronautic, Nanjing 211106, People's Republic of China
- School of Electronic and Optical Engineering, Nanjing University of Science and Technology, Nanjing 210094, People's Republic of China
| | - Yu Diao
- School of Electronic and Optical Engineering, Nanjing University of Science and Technology, Nanjing 210094, People's Republic of China
| | - Mingming Jiang
- College of Science, Nanjing University of Aeronautics & Astronautics, No. 29 Jiangjun Rd, Nanjing 211106, People's Republic of China
- Key Lab Intelligent Nano Materials & Devices, Nanjing University of Aeronautics & Astronautic, Nanjing 211106, People's Republic of China
| | - Caixia Kan
- College of Science, Nanjing University of Aeronautics & Astronautics, No. 29 Jiangjun Rd, Nanjing 211106, People's Republic of China
- Key Lab Intelligent Nano Materials & Devices, Nanjing University of Aeronautics & Astronautic, Nanjing 211106, People's Republic of China
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2
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Bui HQT, Velpula RT, Jian B, Philip MR, Tong HD, Lenka TR, Nguyen HPT. High-performance nanowire ultraviolet light-emitting diodes with potassium hydroxide and ammonium sulfide surface passivation. APPLIED OPTICS 2020; 59:7352-7356. [PMID: 32902502 DOI: 10.1364/ao.400877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 07/26/2020] [Indexed: 06/11/2023]
Abstract
Potassium hydroxide (KOH) and ammonium sulfide (NH4)2Sx have been used as a surface passivation treatment to improve the electrical and optical performance of AlGaN nanowire ultraviolet (UV) light-emitting diodes (LEDs). Enhancements in photoluminescence at 335 nm (49%), optical output power (65%), and electroluminescence (83%), with respect to the as-grown nanowire LED are recorded for the AlGaN nanowire UV LEDs with surface passivation. These enhancements are attributed to the reduced nonradiative recombination on the nanowire surfaces. This study provides a potential surface passivation approach to produce high-power AlGaN nanowire LEDs operating in the UV spectrum.
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3
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Jain B, Velpula RT, Tumuna M, Bui HQT, Jude J, Pham TT, le TV, Hoang AV, Wang R, Nguyen HPT. Enhancing the light extraction efficiency of AlInN nanowire ultraviolet light-emitting diodes with photonic crystal structures. OPTICS EXPRESS 2020; 28:22908-22918. [PMID: 32752544 DOI: 10.1364/oe.396788] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 06/23/2020] [Indexed: 06/11/2023]
Abstract
In this paper, AlInN nanowire ultraviolet light-emitting diodes (LEDs) with emission at ∼299 nm have been successfully demonstrated. We have further studied the light extraction properties of these nanowire LEDs using photonic crystal structures with square and hexagonal lattices of nanowires. The light extraction efficiency (LEE) of the periodic nanowire LED arrays was found to be significantly increased as compared to random nanowire LEDs. The LEEs reach ∼ 56%, and ∼ 63% for the square and hexagonal photonic crystal-based nanowire structures, respectively. Moreover, highly transverse-magnetic polarized emission was observed with dominant vertical light emission for the AlInN nanowire ultraviolet LEDs.
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Høiaas IM, Liudi Mulyo A, Vullum PE, Kim DC, Ahtapodov L, Fimland BO, Kishino K, Weman H. GaN/AlGaN Nanocolumn Ultraviolet Light-Emitting Diode Using Double-Layer Graphene as Substrate and Transparent Electrode. NANO LETTERS 2019; 19:1649-1658. [PMID: 30702300 DOI: 10.1021/acs.nanolett.8b04607] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The many outstanding properties of graphene have impressed and intrigued scientists for the last few decades. Its transparency to light of all wavelengths combined with a low sheet resistance makes it a promising electrode material for novel optoelectronics. So far, no one has utilized graphene as both the substrate and transparent electrode of a functional optoelectronic device. Here, we demonstrate the use of double-layer graphene as a growth substrate and transparent conductive electrode for an ultraviolet light-emitting diode in a flip-chip configuration, where GaN/AlGaN nanocolumns are grown as the light-emitting structure using plasma-assisted molecular beam epitaxy. Although the sheet resistance is increased after nanocolumn growth compared with pristine double-layer graphene, our experiments show that the double-layer graphene functions adequately as an electrode. The GaN/AlGaN nanocolumns are found to exhibit a high crystal quality with no observable defects or stacking faults. Room-temperature electroluminescence measurements show a GaN related near bandgap emission peak at 365 nm and no defect-related yellow emission.
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Affiliation(s)
- Ida Marie Høiaas
- Department of Electronic Systems , Norwegian University of Science and Technology (NTNU) , NO-7491 Trondheim , Norway
| | - Andreas Liudi Mulyo
- Department of Electronic Systems , Norwegian University of Science and Technology (NTNU) , NO-7491 Trondheim , Norway
- Department of Engineering and Applied Sciences , Sophia University , 102-8554 Tokyo , Japan
| | | | - Dong-Chul Kim
- Department of Electronic Systems , Norwegian University of Science and Technology (NTNU) , NO-7491 Trondheim , Norway
| | - Lyubomir Ahtapodov
- Department of Electronic Systems , Norwegian University of Science and Technology (NTNU) , NO-7491 Trondheim , Norway
| | - Bjørn-Ove Fimland
- Department of Electronic Systems , Norwegian University of Science and Technology (NTNU) , NO-7491 Trondheim , Norway
| | - Katsumi Kishino
- Department of Engineering and Applied Sciences , Sophia University , 102-8554 Tokyo , Japan
- Sophia Nanotechnology Research Center , Sophia University , 102-8554 , Tokyo , Japan
| | - Helge Weman
- Department of Electronic Systems , Norwegian University of Science and Technology (NTNU) , NO-7491 Trondheim , Norway
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5
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Peng M, Zheng X, Liu S, Wei H, He Y, Li M, An Y, Song Y, Qiu P. A large-scale, ultrahigh-resolution nanoemitter ordered array with PL brightness enhanced by PEALD-grown AlN coating. NANOSCALE 2019; 11:3710-3717. [PMID: 30742183 DOI: 10.1039/c8nr07946c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
III-nitride solid-state microdisplays have significant advantages, including high brightness and high resolution, for the development of advanced displays, high-definition projectors, head-mounted displays, large-capacity optical communication systems, and so forth. Herein, a high-brightness InGaN/GaN multiple-quantum-well (MQW) nanoemitter array with an ultrahigh resolution of 31 750 dpi was achieved by combining a top-down fabrication with surface passivation of plasma-enhanced atomic layer deposition (PEALD)-grown AlN coating. With regard to the nanometer-level top-down etching, the surface damage or defects on the newly-formed sidewall play a significant role in the photoluminescence (PL) quality. Note that these arrays can be effectively passivated by the PEALD-grown AlN coating with an over 345% PL enhancement. In addition, a sharp band bending at the interface of the luminescent InGaN QW and the AlN coating layer can electrically drift away the photogenerated electrons from the surface traps; this leads to enhancement of the bulk PL radiative recombination with a fast PL decay rate. Therefore, we have demonstrated a feasible way for realizing an advanced nanoemitter array with both high brightness and ultrahigh resolution for future smart displays, high-resolution imaging, big-data optical information systems and so on.
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Affiliation(s)
- Mingzeng Peng
- Beijing Key Laboratory for Magneto-Photoelectrical Composite and Interface Science, School of Mathematics and Physics, University of Science and Technology Beijing, No. 30, Xueyuan Road, Beijing 100083, China.
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Le BH, Liu X, Tran NH, Zhao S, Mi Z. An electrically injected AlGaN nanowire defect-free photonic crystal ultraviolet laser. OPTICS EXPRESS 2019; 27:5843-5850. [PMID: 30876179 DOI: 10.1364/oe.27.005843] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 11/09/2018] [Indexed: 06/09/2023]
Abstract
We report on the demonstration of an electrically injected AlGaN nanowire photonic crystal laser that can operate in the ultraviolet spectral range. The nanowire heterostructures were grown on sapphire substrate using a site-controlled selective area growth process. By exploiting the topological high-Q resonance of a defect-free nanowire photonic crystal, we have demonstrated electrically pumped lasers that can operate at 369.5 nm with a relatively low threshold current density of ~2.1 kA/cm2 under continuous wave operation at room-temperature. This work provides a promising approach for achieving low threshold semiconductor laser diodes operating in the UV spectral range that were previously difficult.
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Zhao C, Ebaid M, Zhang H, Priante D, Janjua B, Zhang D, Wei N, Alhamoud AA, Shakfa MK, Ng TK, Ooi BS. Quantified hole concentration in AlGaN nanowires for high-performance ultraviolet emitters. NANOSCALE 2018; 10:15980-15988. [PMID: 29897082 DOI: 10.1039/c8nr02615g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
p-Type doping in wide bandgap and new classes of ultra-wide bandgap materials has long been a scientific and engineering problem. The challenges arise from the large activation energy of dopants and high densities of dislocations in materials. We report here, a significantly enhanced p-type conduction using high-quality AlGaN nanowires. For the first time, the hole concentration in Mg-doped AlGaN nanowires is quantified. The incorporation of Mg into AlGaN was verified by correlation with photoluminescence and Raman measurements. The open-circuit potential measurements further confirmed the p-type conductivity, while Mott-Schottky experiments measured a hole concentration of 1.3 × 1019 cm-3. These results from photoelectrochemical measurements allow us to design prototype ultraviolet (UV) light-emitting diodes (LEDs) incorporating the AlGaN quantum-disks-in-nanowire and an optimized p-type AlGaN contact layer for UV-transparency. The ∼335 nm LEDs exhibited a low turn-on voltage of 5 V with a series resistance of 32 Ω, due to the efficient p-type doping of the AlGaN nanowires. The bias-dependent Raman measurements further revealed the negligible self-heating of devices. This study provides an attractive solution to evaluate the electrical properties of AlGaN, which is applicable to other wide bandgap nanostructures. Our results are expected to open doors to new applications for wide and ultra-wide bandgap materials.
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Affiliation(s)
- Chao Zhao
- King Abdullah University of Science and Technology (KAUST), Photonics Laboratory, Thuwal 23955-6900, Saudi Arabia.
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8
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Ultraviolet Detectors Based on Wide Bandgap Semiconductor Nanowire: A Review. SENSORS 2018; 18:s18072072. [PMID: 29958452 PMCID: PMC6068994 DOI: 10.3390/s18072072] [Citation(s) in RCA: 146] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 06/05/2018] [Accepted: 06/27/2018] [Indexed: 12/25/2022]
Abstract
Ultraviolet (UV) detectors have attracted considerable attention in the past decade due to their extensive applications in the civil and military fields. Wide bandgap semiconductor-based UV detectors can detect UV light effectively, and nanowire structures can greatly improve the sensitivity of sensors with many quantum effects. This review summarizes recent developments in the classification and principles of UV detectors, i.e., photoconductive type, Schottky barrier type, metal-semiconductor-metal (MSM) type, p-n junction type and p-i-n junction type. The current state of the art in wide bandgap semiconductor materials suitable for producing nanowires for use in UV detectors, i.e., metallic oxide, III-nitride and SiC, during the last five years is also summarized. Finally, novel types of UV detectors such as hybrid nanostructure detectors, self-powered detectors and flexible detectors are introduced.
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Liu X, Le BH, Woo SY, Zhao S, Pofelski A, Botton GA, Mi Z. Selective area epitaxy of AlGaN nanowire arrays across nearly the entire compositional range for deep ultraviolet photonics. OPTICS EXPRESS 2017; 25:30494-30502. [PMID: 29221077 DOI: 10.1364/oe.25.030494] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 11/12/2017] [Indexed: 06/07/2023]
Abstract
Semiconductor light sources operating in the ultraviolet (UV)-C band (100-280 nm) are in demand for a broad range of applications but suffer from extremely low efficiency. AlGaN nanowire photonic crystals promise to break the efficiency bottleneck of deep UV photonics. We report, for the first time, site-controlled epitaxy of AlGaN nanowire arrays with Al incorporation controllably varied across nearly the entire compositional range. It is also observed that an Al-rich AlGaN shell structure is spontaneously formed, significantly suppressing nonradiative surface recombination. An internal quantum efficiency up to 45% was measured at room-temperature. We have further demonstrated large area AlGaN nanowire LEDs operating in the UV-C band on sapphire substrate, which exhibit excellent optical and electrical performance, including a small turn-on voltage of ~4.4 V and an output power of ~0.93 W/cm2 at a current density of 252 A/cm2. The controlled synthesis of AlGaN subwavelength nanostructures with well-defined size, spacing, and spatial arrangement and tunable emission opens up new opportunities for developing high efficiency LEDs and lasers and promises to break the efficiency bottleneck of deep UV photonics.
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Janjua B, Sun H, Zhao C, Anjum DH, Wu F, Alhamoud AA, Li X, Albadri AM, Alyamani AY, El-Desouki MM, Ng TK, Ooi BS. Self-planarized quantum-disks-in-nanowires ultraviolet-B emitters utilizing pendeo-epitaxy. NANOSCALE 2017; 9:7805-7813. [PMID: 28290591 DOI: 10.1039/c7nr00006e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The growth of self-assembled, vertically oriented and uniform nanowires (NWs) has remained a challenge for efficient light-emitting devices. Here, we demonstrate dislocation-free AlGaN NWs with spontaneous coalescence, which are grown by plasma-assisted molecular beam epitaxy on an n-type doped silicon (100) substrate. A high density of NWs (filling factor >95%) was achieved under optimized growth conditions, enabling device fabrication without planarization using ultraviolet (UV)-absorbing polymer materials. UV-B (280-320 nm) light-emitting diodes (LEDs), which emit at ∼303 nm with a narrow full width at half maximum (FWHM) (∼20 nm) of the emission spectrum, are demonstrated using a large active region ("active region/NW length-ratio" ∼50%) embedded with 15 stacks of AlxGa1-xN/AlyGa1-yN quantum-disks (Qdisks). To improve the carrier injection, a graded layer is introduced at the AlGaN/GaN interfaces on both p- and n-type regions. This work demonstrates a viable approach to easily fabricate ultra-thin, efficient UV optoelectronic devices on low-cost and scalable silicon substrates.
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Affiliation(s)
- B Janjua
- King Abdullah University of Science and Technology (KAUST), Photonics Laboratory, Thuwal 23955-6900, Saudi Arabia.
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11
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Sadaf SM, Zhao S, Wu Y, Ra YH, Liu X, Vanka S, Mi Z. An AlGaN Core-Shell Tunnel Junction Nanowire Light-Emitting Diode Operating in the Ultraviolet-C Band. NANO LETTERS 2017; 17:1212-1218. [PMID: 28081598 DOI: 10.1021/acs.nanolett.6b05002] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
To date, semiconductor light emitting diodes (LEDs) operating in the deep ultraviolet (UV) spectral range exhibit very low efficiency due to the presence of large densities of defects and extremely inefficient p-type conduction of conventional AlGaN quantum well heterostructures. We have demonstrated that such critical issues can be potentially addressed by using nearly defect-free AlGaN tunnel junction core-shell nanowire heterostructures. The core-shell nanowire arrays exhibit high photoluminescence efficiency (∼80%) in the UV-C band at room temperature. With the incorporation of an epitaxial Al tunnel junction, the p-(Al)GaN contact-free nanowire deep UV LEDs showed nearly one order of magnitude reduction in the device resistance, compared to the conventional nanowire p-i-n device. The unpackaged Al tunnel junction deep UV LEDs exhibit an output power >8 mW and a peak external quantum efficiency ∼0.4%, which are nearly one to two orders of magnitude higher than previously reported AlGaN nanowire devices. Detailed studies further suggest that the maximum achievable efficiency is limited by electron overflow and poor light extraction efficiency due to the TM polarized emission.
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Affiliation(s)
- S M Sadaf
- Department of Electrical and Computer Engineering, McGill University , 3480 University Street, Montreal, Quebec H3A 0E9, Canada
| | - S Zhao
- Department of Electrical and Computer Engineering, McGill University , 3480 University Street, Montreal, Quebec H3A 0E9, Canada
| | - Y Wu
- Department of Electrical and Computer Engineering, McGill University , 3480 University Street, Montreal, Quebec H3A 0E9, Canada
| | - Y-H Ra
- Department of Electrical and Computer Engineering, McGill University , 3480 University Street, Montreal, Quebec H3A 0E9, Canada
| | - X Liu
- Department of Electrical and Computer Engineering, McGill University , 3480 University Street, Montreal, Quebec H3A 0E9, Canada
| | - S Vanka
- Department of Electrical and Computer Engineering, McGill University , 3480 University Street, Montreal, Quebec H3A 0E9, Canada
| | - Z Mi
- Department of Electrical Engineering and Computer Science, Center for Photonics and Multiscale Nanomaterials, University of Michigan , Ann Arbor, Michigan 48109, United States
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12
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Janjua B, Sun H, Zhao C, Anjum DH, Priante D, Alhamoud AA, Wu F, Li X, Albadri AM, Alyamani AY, El-Desouki MM, Ng TK, Ooi BS. Droop-free Al xGa 1-xN/Al yGa 1-yN quantum-disks-in-nanowires ultraviolet LED emitting at 337 nm on metal/silicon substrates. OPTICS EXPRESS 2017; 25:1381-1390. [PMID: 28158020 DOI: 10.1364/oe.25.001381] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 01/12/2017] [Indexed: 06/06/2023]
Abstract
Currently the AlGaN-based ultraviolet (UV) solid-state lighting research suffers from numerous challenges. In particular, low internal quantum efficiency, low extraction efficiency, inefficient doping, large polarization fields, and high dislocation density epitaxy constitute bottlenecks in realizing high power devices. Despite the clear advantage of quantum-confinement nanostructure, it has not been widely utilized in AlGaN-based nanowires. Here we utilize the self-assembled nanowires (NWs) with embedding quantum-disks (Qdisks) to mitigate these issues, and achieve UV emission of 337 nm at 32 A/cm2 (80 mA in 0.5 × 0.5 mm2 device), a turn-on voltage of ~5.5 V and droop-free behavior up to 120 A/cm2 of injection current. The device was grown on a titanium-coated n-type silicon substrate, to improve current injection and heat dissipation. A narrow linewidth of 11.7 nm in the electroluminescence spectrum and a strong wavefunctions overlap factor of 42% confirm strong quantum confinement within uniformly formed AlGaN/AlGaN Qdisks, verified using transmission electron microscopy (TEM). The nitride-based UV nanowires light-emitting diodes (NWs-LEDs) grown on low cost and scalable metal/silicon template substrate, offers a scalable, environment friendly and low cost solution for numerous applications, such as solid-state lighting, spectroscopy, medical science and security.
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Wang C, Peng D, Zhao J, Bao R, Li T, Tian L, Dong L, Shen C, Pan C. CdS@SiO 2 Core-Shell Electroluminescent Nanorod Arrays Based on a Metal-Insulator-Semiconductor Structure. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2016; 12:5734-5740. [PMID: 27572124 DOI: 10.1002/smll.201601548] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2016] [Revised: 07/27/2016] [Indexed: 06/06/2023]
Abstract
Enormous advancement has been achieved in the field of one-dimensional (1D) semiconductor light-emitting devices (LEDs), however, LEDs based on 1D CdS nanostructures have been rarely reported. The fabrication of CdS@SiO2 core-shell nanorod array LEDs based on a Au-SiO2 -CdS metal-insulator-semiconductor (MIS) structure is presented. The MIS LEDs exhibit strong yellow emission with a low threshold voltage of 2.7 V. Electroluminescence with a broad emission ranging from 450 nm to 800 nm and a shoulder peak at 700 nm is observed, which is related to the defects and surface states of the CdS nanorods. The influence of the SiO2 shell thickness on the electroluminescence intensity is systematically investigated. The devices have a high light-emitting spatial resolution of 1.5 μm and maintain an excellent emission property even after shelving at room temperature for at least three months. Moreover, the fabrication process is simple and cost effective and the MIS device could be fabricated on a flexible substrate, which holds great potential for application as a flexible light source. This prototype is expected to open up a new route towards the development of large-scale light-emitting devices with excellent attributes, such as high resolution, low cost, and good stability.
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Affiliation(s)
- Chunfeng Wang
- Engineering Research Center for Advanced Polymer Processing Technology, School of Materials Science and Engineering, Zhengzhou University, 100 Science Avenue, Zhengzhou, 450001, P. R. China
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Science, National Center for Nanoscience and Technology (NCNST), Beijing, 100083, P. R. China
| | - Dengfeng Peng
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Science, National Center for Nanoscience and Technology (NCNST), Beijing, 100083, P. R. China
| | - Jing Zhao
- Engineering Research Center for Advanced Polymer Processing Technology, School of Materials Science and Engineering, Zhengzhou University, 100 Science Avenue, Zhengzhou, 450001, P. R. China
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Science, National Center for Nanoscience and Technology (NCNST), Beijing, 100083, P. R. China
| | - Rongrong Bao
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Science, National Center for Nanoscience and Technology (NCNST), Beijing, 100083, P. R. China
| | - Tianfeng Li
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Science, National Center for Nanoscience and Technology (NCNST), Beijing, 100083, P. R. China
| | - Li Tian
- Engineering Research Center for Advanced Polymer Processing Technology, School of Materials Science and Engineering, Zhengzhou University, 100 Science Avenue, Zhengzhou, 450001, P. R. China
| | - Lin Dong
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Science, National Center for Nanoscience and Technology (NCNST), Beijing, 100083, P. R. China.
- School of Physical Engineering, Zhengzhou University, 100 Science Avenue, Zhengzhou, 450001, P. R. China.
| | - Changyu Shen
- Engineering Research Center for Advanced Polymer Processing Technology, School of Materials Science and Engineering, Zhengzhou University, 100 Science Avenue, Zhengzhou, 450001, P. R. China.
| | - Caofeng Pan
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Science, National Center for Nanoscience and Technology (NCNST), Beijing, 100083, P. R. China.
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Le BH, Zhao S, Liu X, Woo SY, Botton GA, Mi Z. Controlled Coalescence of AlGaN Nanowire Arrays: An Architecture for Nearly Dislocation-Free Planar Ultraviolet Photonic Device Applications. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2016; 28:8446-8454. [PMID: 27489074 DOI: 10.1002/adma.201602645] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 07/05/2016] [Indexed: 06/06/2023]
Abstract
Nearly dislocation-free semipolar AlGaN templates are achieved on c-plane sapphire substrate through controlled nanowire coalescence by selective-area epitaxy. The coalesced Mg-doped AlGaN layers exhibit superior charge-carrier-transport properties. Semipolar-AlGaN ultraviolet light-emitting diodes demonstrate excellent performance. This work establishes the use of engineered nanowire structures as a viable architecture to achieve large-area, dislocation-free planar photonic and electronic devices.
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Affiliation(s)
- Binh H Le
- Department of Electrical and Computer Engineering, McGill University, Montreal, QC, H3A 0E9, Canada
| | - Songrui Zhao
- Department of Electrical and Computer Engineering, McGill University, Montreal, QC, H3A 0E9, Canada
| | - Xianhe Liu
- Department of Electrical and Computer Engineering, McGill University, Montreal, QC, H3A 0E9, Canada
| | - Steffi Y Woo
- Department of Materials Science and Engineering, Canadian Centre for Electron Microscopy, McMaster University, 1280 Main Street West, Hamilton, ON, L8S 4M1, Canada
| | - Gianluigi A Botton
- Department of Materials Science and Engineering, Canadian Centre for Electron Microscopy, McMaster University, 1280 Main Street West, Hamilton, ON, L8S 4M1, Canada
| | - Zetian Mi
- Department of Electrical and Computer Engineering, McGill University, Montreal, QC, H3A 0E9, Canada.
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15
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Sivadasan AK, Madapu KK, Dhara S. The light-matter interaction of a single semiconducting AlGaN nanowire and noble metal Au nanoparticles in the sub-diffraction limit. Phys Chem Chem Phys 2016; 18:23680-5. [PMID: 27511614 DOI: 10.1039/c6cp04681a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Near field scanning optical microscopy (NSOM) is not only a tool for imaging of sub-diffraction limited objects but also a prominent characteristic tool for understanding the intrinsic properties of nanostructures. In order to understand light-matter interactions in the near field regime using a NSOM technique with an excitation of 532 nm (2.33 eV), we selected an isolated single semiconducting AlGaN nanowire (NW) of diameter ∼120 nm grown via a vapor liquid solid (VLS) mechanism along with a metallic Au nanoparticle (NP) catalyst. The role of electronic transitions from different native defect related energy states of AlGaN is discussed in understanding the NSOM images for the semiconducting NW. The effect of strong surface plasmon resonance absorption of an excitation laser on the NSOM images for Au NPs, involved in the VLS growth mechanism of NWs, is also observed.
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Affiliation(s)
- A K Sivadasan
- Nanomaterials and Sensor Section, Surface and Nanoscience Division, Indira Gandhi Centre for Atomic Research, Homi Bhabha National Institute, Kalpakkam, 603102, Tamil Nadu, India.
| | - Kishore K Madapu
- Nanomaterials and Sensor Section, Surface and Nanoscience Division, Indira Gandhi Centre for Atomic Research, Homi Bhabha National Institute, Kalpakkam, 603102, Tamil Nadu, India.
| | - Sandip Dhara
- Nanomaterials and Sensor Section, Surface and Nanoscience Division, Indira Gandhi Centre for Atomic Research, Homi Bhabha National Institute, Kalpakkam, 603102, Tamil Nadu, India.
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Sarwar ATMG, May BJ, Chisholm MF, Duscher GJ, Myers RC. Ultrathin GaN quantum disk nanowire LEDs with sub-250 nm electroluminescence. NANOSCALE 2016; 8:8024-8032. [PMID: 27019949 DOI: 10.1039/c6nr00132g] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
By quantum confining GaN at monolayer thickness with AlN barriers inside of a nanowire, deep ultraviolet LEDs are demonstrated. Full three-dimensional strain dependent energy band simulations are carried out within multiple quantum disk (MQD) GaN/AlN nanowire superlattice heterostructures. It is found that, even within the same nanowire MQD, the emission energy of the ultrathin GaN QDs varies from disk to disk due to the changing strain distribution and polarization charge induced energy band bending along the axial nanowire direction. MQD heterostructures are grown by plasma-assisted molecular beam epitaxy to form self-assembled catalyst-free nanowires with 1 to 2 monolayer thick GaN insertions within an AlN matrix. Photoluminescence peaks are observed at 295 nm and 283 nm from the 2 ML and 1 ML thick MQD samples, respectively. Polarization-doped nanowire LEDs are grown incorporating 1 ML thick GaN MQD active regions from which we observe deep ultraviolet electroluminescence. The shortest LED wavelength peak observed is 240 nm and attributed to electron hole recombination within 1 ML thick GaN QDs.
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Affiliation(s)
- A T M Golam Sarwar
- Department of Electrical and Computer Engineering, The Ohio State University, Columbus, OH 43210, USA.
| | - Brelon J May
- Department of Materials Science and Engineering, The Ohio State University, Columbus, OH 43210, USA
| | - Matthew F Chisholm
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Gerd J Duscher
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA and Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996, USA
| | - Roberto C Myers
- Department of Electrical and Computer Engineering, The Ohio State University, Columbus, OH 43210, USA. and Department of Materials Science and Engineering, The Ohio State University, Columbus, OH 43210, USA
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17
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Belloeil M, Gayral B, Daudin B. Quantum Dot-Like Behavior of Compositional Fluctuations in AlGaN Nanowires. NANO LETTERS 2016; 16:960-966. [PMID: 26785291 DOI: 10.1021/acs.nanolett.5b03904] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We report on the structural and optical properties of AlxGa(1-x)N nanowire sections grown by plasma-assisted molecular beam epitaxy on GaN nanowire bases used as a template. Based on a combination of scanning electron microscopy, microphotoluminescence, time-resolved microphotoluminescence, and photon correlation experiments, it is shown that compositional fluctuations in AlxGa(1-x)N sections associated with carrier localization optically behave as quantum dots. Moreover, most of the micro-optical properties of such fluctuations are demonstrated to be very little dependent on kinetic growth parameters such as AlxGa(1-x)N growth temperature and AlN molar fraction in the alloy, which govern the macrostructural properties of AlxGa(1-x)N sections.
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Affiliation(s)
- M Belloeil
- Univ. Grenoble Alpes , F-38000 Grenoble, France
- CEA, INAC-PHELIQS, "Nanophysics and Semiconductors" Group, F-38000 Grenoble, France
| | - B Gayral
- Univ. Grenoble Alpes , F-38000 Grenoble, France
- CEA, INAC-PHELIQS, "Nanophysics and Semiconductors" Group, F-38000 Grenoble, France
| | - B Daudin
- Univ. Grenoble Alpes , F-38000 Grenoble, France
- CEA, INAC-PHELIQS, "Nanophysics and Semiconductors" Group, F-38000 Grenoble, France
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18
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Zhao S, Woo SY, Bugnet M, Liu X, Kang J, Botton GA, Mi Z. Three-Dimensional Quantum Confinement of Charge Carriers in Self-Organized AlGaN Nanowires: A Viable Route to Electrically Injected Deep Ultraviolet Lasers. NANO LETTERS 2015; 15:7801-7. [PMID: 26539880 DOI: 10.1021/acs.nanolett.5b02133] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
We report on the molecular beam epitaxial growth and structural characterization of self-organized AlGaN nanowire arrays on Si substrate with high luminescence efficiency emission in the deep ultraviolet (UV) wavelength range. It is found that, with increasing Al concentration, atomic-scale compositional modulations can be realized, leading to three-dimensional quantum confinement of charge carriers. By further exploiting the Anderson localization of light, we have demonstrated, for the first time, electrically injected AlGaN lasers in the deep UV band operating at room temperature. The laser operates at ∼289 nm and exhibits a threshold of 300 A/cm(2), which is significantly smaller compared to the previously reported electrically injected AlGaN multiple quantum well lasers.
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Affiliation(s)
- S Zhao
- Department of Electrical and Computer Engineering, McGill University , 3480 University Street, Montreal, Quebec H3A 0E9, Canada
| | - S Y Woo
- Department of Materials Science and Engineering, Canadian Centre for Electron Microscopy, McMaster University , 1280 Main Street West, Hamilton, Ontario L8S 4M1, Canada
| | - M Bugnet
- Department of Materials Science and Engineering, Canadian Centre for Electron Microscopy, McMaster University , 1280 Main Street West, Hamilton, Ontario L8S 4M1, Canada
| | - X Liu
- Department of Electrical and Computer Engineering, McGill University , 3480 University Street, Montreal, Quebec H3A 0E9, Canada
| | - J Kang
- Department of Electrical and Computer Engineering, McGill University , 3480 University Street, Montreal, Quebec H3A 0E9, Canada
| | - G A Botton
- Department of Materials Science and Engineering, Canadian Centre for Electron Microscopy, McMaster University , 1280 Main Street West, Hamilton, Ontario L8S 4M1, Canada
| | - Z Mi
- Department of Electrical and Computer Engineering, McGill University , 3480 University Street, Montreal, Quebec H3A 0E9, Canada
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19
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E Y, Hao Z, Yu J, Wu C, Liu R, Wang L, Xiong B, Wang J, Han Y, Sun C, Luo Y. MBE Growth of AlN Nanowires on Si Substrates by Aluminizing Nucleation. NANOSCALE RESEARCH LETTERS 2015; 10:383. [PMID: 26437653 PMCID: PMC4593981 DOI: 10.1186/s11671-015-1083-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 09/21/2015] [Indexed: 06/05/2023]
Abstract
By introducing an aluminization process to achieve nucleation of nanowires (NWs), spontaneous growth of AlN NWs on Si substrates has been realized by plasma-assisted molecular beam epitaxy. The AlN NWs are grown from the nuclei formed by the aluminization process, and the NW density and diameter can be controlled by the aluminization parameters. The influence of growth conditions on the morphologies of AlN NWs is carefully investigated. Island-like films are found to grow between the NWs due to poor migration ability of Al adatoms. The films are proved to be Al-polar different from the N-polar AlN NWs, which can explain the absence of newly formed NWs. Increasing the V/III ratio can efficiently suppress the growth of Al-polar AlN films.
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Affiliation(s)
- Yanxiong E
- Tsinghua National Laboratory for Information Science and Technology, Department of Electronic Engineering, Tsinghua University, Beijing, 100084, People's Republic of China.
| | - Zhibiao Hao
- Tsinghua National Laboratory for Information Science and Technology, Department of Electronic Engineering, Tsinghua University, Beijing, 100084, People's Republic of China.
| | - Jiadong Yu
- Tsinghua National Laboratory for Information Science and Technology, Department of Electronic Engineering, Tsinghua University, Beijing, 100084, People's Republic of China.
| | - Chao Wu
- Tsinghua National Laboratory for Information Science and Technology, Department of Electronic Engineering, Tsinghua University, Beijing, 100084, People's Republic of China.
| | - Runze Liu
- Tsinghua National Laboratory for Information Science and Technology, Department of Electronic Engineering, Tsinghua University, Beijing, 100084, People's Republic of China.
| | - Lai Wang
- Tsinghua National Laboratory for Information Science and Technology, Department of Electronic Engineering, Tsinghua University, Beijing, 100084, People's Republic of China.
| | - Bing Xiong
- Tsinghua National Laboratory for Information Science and Technology, Department of Electronic Engineering, Tsinghua University, Beijing, 100084, People's Republic of China.
| | - Jian Wang
- Tsinghua National Laboratory for Information Science and Technology, Department of Electronic Engineering, Tsinghua University, Beijing, 100084, People's Republic of China.
| | - Yanjun Han
- Tsinghua National Laboratory for Information Science and Technology, Department of Electronic Engineering, Tsinghua University, Beijing, 100084, People's Republic of China.
| | - Changzheng Sun
- Tsinghua National Laboratory for Information Science and Technology, Department of Electronic Engineering, Tsinghua University, Beijing, 100084, People's Republic of China.
| | - Yi Luo
- Tsinghua National Laboratory for Information Science and Technology, Department of Electronic Engineering, Tsinghua University, Beijing, 100084, People's Republic of China.
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20
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Zhao S, Djavid M, Mi Z. Surface Emitting, High Efficiency Near-Vacuum Ultraviolet Light Source with Aluminum Nitride Nanowires Monolithically Grown on Silicon. NANO LETTERS 2015; 15:7006-7009. [PMID: 26375576 DOI: 10.1021/acs.nanolett.5b03040] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
To date, it has remained challenging to realize electrically injected light sources in the vacuum ultraviolet wavelength range (∼200 nm or shorter), which are important for a broad range of applications, including sensing, surface treatment, and photochemical analysis. In this Letter, we have demonstrated such a light source with molecular beam epitaxially grown aluminum nitride (AlN) nanowires on low cost, large area Si substrate. Detailed angle dependent electroluminescence studies suggest that, albeit the light is TM polarized, the dominant light emission direction is from the nanowire top surface, that is, along the c axis, due to the strong light scattering effect. Such an efficient surface emitting device was not previously possible using conventional c-plane AlN planar structures. The AlN nanowire LEDs exhibit an extremely large electrical efficiency (>85%), which is nearly ten times higher than the previously reported AlN planar devices. Our detailed studies further suggest that the performance of AlN nanowire LEDs is predominantly limited by electron overflow. This study provides important insight on the fundamental emission characteristics of AlN nanowire LEDs and also offers a viable path to realize an efficient surface emitting near-vacuum ultraviolet light source through direct electrical injection.
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Affiliation(s)
- S Zhao
- Department of Electrical and Computer Engineering, McGill University , 3480 University Street, Montreal H3A 0E9, Canada
| | - M Djavid
- Department of Electrical and Computer Engineering, McGill University , 3480 University Street, Montreal H3A 0E9, Canada
| | - Z Mi
- Department of Electrical and Computer Engineering, McGill University , 3480 University Street, Montreal H3A 0E9, Canada
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21
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Nguyen HPT, Djavid M, Woo SY, Liu X, Connie AT, Sadaf S, Wang Q, Botton GA, Shih I, Mi Z. Engineering the carrier dynamics of InGaN nanowire white light-emitting diodes by distributed p-AlGaN electron blocking layers. Sci Rep 2015; 5:7744. [PMID: 25592057 PMCID: PMC4296300 DOI: 10.1038/srep07744] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 11/28/2014] [Indexed: 11/30/2022] Open
Abstract
We report on the demonstration of a new type of axial nanowire LED heterostructures, with the use of self-organized InGaN/AlGaN dot-in-a-wire core-shell nanowire arrays. The large bandgap AlGaN shell is spontaneously formed on the sidewall of the nanowire during the growth of AlGaN barrier of the quantum dot active region. As such, nonradiative surface recombination, that dominates the carrier dynamics of conventional axial nanowire LED structures, can be largely eliminated, leading to significantly increased carrier lifetime from ~0.3 ns to 4.5 ns. The luminescence emission is also enhanced by orders of magnitude. Moreover, the p-doped AlGaN barrier layers can function as distributed electron blocking layers (EBLs), which is found to be more effective in reducing electron overflow, compared to the conventional AlGaN EBL. The device displays strong white-light emission, with a color rendering index of ~95. An output power of >5 mW is measured for a 1 mm × 1 mm device, which is more than 500 times stronger than the conventional InGaN axial nanowire LEDs without AlGaN distributed EBLs.
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Affiliation(s)
- Hieu Pham Trung Nguyen
- 1] Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, Quebec H3A 0E9, Canada [2] Department of Electrical and Computer Engineering, New Jersey Institute of Technology, University Heights, Newark, New Jersey 07102
| | - Mehrdad Djavid
- Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, Quebec H3A 0E9, Canada
| | - Steffi Y Woo
- Department of Materials Science and Engineering, Canadian Centre for Electron Microscopy and Brockhouse Institute for Materials Research, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4L7 Canada
| | - Xianhe Liu
- Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, Quebec H3A 0E9, Canada
| | - Ashfiqua T Connie
- Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, Quebec H3A 0E9, Canada
| | - Sharif Sadaf
- Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, Quebec H3A 0E9, Canada
| | - Qi Wang
- Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, Quebec H3A 0E9, Canada
| | - Gianluigi A Botton
- Department of Materials Science and Engineering, Canadian Centre for Electron Microscopy and Brockhouse Institute for Materials Research, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4L7 Canada
| | - Ishiang Shih
- Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, Quebec H3A 0E9, Canada
| | - Zetian Mi
- Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, Quebec H3A 0E9, Canada
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