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Gibasiewicz K, Bojarska-Cieślińska A, Muzioł G, Skierbiszewski C, Grzanka S, Kafar A, Perlin P, Najda S, Suski T. InGaN blue light emitting micro-diodes with current path defined by tunnel junction. OPTICS LETTERS 2020; 45:4332-4335. [PMID: 32735291 DOI: 10.1364/ol.394629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 06/10/2020] [Indexed: 06/11/2023]
Abstract
We have fabricated tunnel-junction InGaN micro-LEDs using plasma-assisted molecular beam epitaxy technology, with top-down processing on GaN substrates. Devices have diameters between 5 µm and 100 µm. All of the devices emit light at 450 nm at a driving current density of about 10Acm-2. We demonstrate that within micro-LEDs ranging in size from 100 µm down to 5 µm, the properties of these devices, both electrical and optical, are fully scalable. That means we can reproduce all electro-optical characteristics using a single set of parameters. Most notably, we do not observe any enhancement of non-radiative recombination for the smallest devices. We assign this result to a modification of the fabrication process, i.e., replacement of deep dry etching by a tunnel junction for the current confinement. These devices show excellent thermal stability of their light emission characteristics, enabling operation at current densities up to 1kAcm-2.
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Saha PK, Pendem V, Chouksey S, Udai A, Aggarwal T, Ganguly S, Saha D. Enhanced luminescence from InGaN/GaN nano-disk in a wire array caused by surface potential modulation during wet treatment. NANOTECHNOLOGY 2019; 30:104001. [PMID: 30557860 DOI: 10.1088/1361-6528/aaf8de] [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
Here we have demonstrated the profound impact of surface potential on the luminescence of an array of InGaN/GaN nano-disk in a wire heterostructure. The change in surface potential is brought about by a combination of dry and successive wet-processing treatments. The photoluminescence (PL) properties are determined as a function of size and height of this array of nano-disks. The observed characteristics are coherently explained by considering a change in quantum confinement induced by the change in surface potential, quantum-confined Stark effect, exciton binding energy and strain relaxation for varying surface potential. The change in hole bound state energy due to parabolic potential well near the side-wall is found to be the dominating factor. The PL peak position, full width at half-maximum, strain relaxation and integrated PL intensity are studied as a function of incident power and temperature. The devices demonstrate higher integrated PL intensity and slope efficiency.
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Affiliation(s)
- Pratim Kumar Saha
- Applied Quantum Mechanics Laboratory, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
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Jiang T, Xu SR, Zhang JC, Xie Y, Hao Y. Spatially resolved and orientation dependent Raman mapping of epitaxial lateral overgrowth nonpolar a-plane GaN on r-plane sapphire. Sci Rep 2016; 6:19955. [PMID: 26821824 PMCID: PMC4731808 DOI: 10.1038/srep19955] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 12/21/2015] [Indexed: 11/22/2022] Open
Abstract
Uncoalesced a-plane GaN epitaxial lateral overgrowth (ELO) structures have been synthesized along two mask stripe orientations on a-plane GaN template by MOCVD. The morphology of two ELO GaN structures is performed by Scanning electronic microscopy. The anisotropy of crystalline quality and stress are investigated by micro-Raman spectroscopy. According to the Raman mapping spectra, the variations on the intensity, peak shift and the full width at half maximum (FWHM) of GaN E2 (high) peak indicate that the crystalline quality improvement occurs in the window region of the GaN stripes along [0001], which is caused by the dislocations bending towards the sidewalls. Conversely, the wing regions have better quality with less stress as the dislocations propagated upwards when the GaN stripes are along []. Spatial cathodoluminescence mapping results further support the explanation for the different dislocation growth mechanisms in the ELO processes with two different mask stripe orientations.
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Affiliation(s)
- Teng Jiang
- Wide Bandap Semiconductor Technology Disciplines State Key Laboratory, School of Microelectronics, Xidian University, Xi’an 710071, China
| | - Sheng-rui Xu
- Wide Bandap Semiconductor Technology Disciplines State Key Laboratory, School of Microelectronics, Xidian University, Xi’an 710071, China
| | - Jin-cheng Zhang
- Wide Bandap Semiconductor Technology Disciplines State Key Laboratory, School of Microelectronics, Xidian University, Xi’an 710071, China
| | - Yong Xie
- School of Advanced Materials and Nanotechnology, Xidian University, Xi’an 710071, China
| | - Yue Hao
- Wide Bandap Semiconductor Technology Disciplines State Key Laboratory, School of Microelectronics, Xidian University, Xi’an 710071, China
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Peng M, Li Z, Liu C, Zheng Q, Shi X, Song M, Zhang Y, Du S, Zhai J, Wang ZL. High-resolution dynamic pressure sensor array based on piezo-phototronic effect tuned photoluminescence imaging. ACS NANO 2015; 9:3143-50. [PMID: 25712580 DOI: 10.1021/acsnano.5b00072] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A high-resolution dynamic tactile/pressure display is indispensable to the comprehensive perception of force/mechanical stimulations such as electronic skin, biomechanical imaging/analysis, or personalized signatures. Here, we present a dynamic pressure sensor array based on pressure/strain tuned photoluminescence imaging without the need for electricity. Each sensor is a nanopillar that consists of InGaN/GaN multiple quantum wells. Its photoluminescence intensity can be modulated dramatically and linearly by small strain (0-0.15%) owing to the piezo-phototronic effect. The sensor array has a high pixel density of 6350 dpi and exceptional small standard deviation of photoluminescence. High-quality tactile/pressure sensing distribution can be real-time recorded by parallel photoluminescence imaging without any cross-talk. The sensor array can be inexpensively fabricated over large areas by semiconductor product lines. The proposed dynamic all-optical pressure imaging with excellent resolution, high sensitivity, good uniformity, and ultrafast response time offers a suitable way for smart sensing, micro/nano-opto-electromechanical systems.
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Affiliation(s)
- Mingzeng Peng
- †Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing 100083, China
| | - Zhou Li
- †Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing 100083, China
- ∥Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China
| | - Caihong Liu
- †Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing 100083, China
| | - Qiang Zheng
- †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
| | - Ming Song
- †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
| | - Shiyu Du
- §Division of Functional Materials and Nanodevices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang 315201, 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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Wang Q, Tian Z, Li Y, Tian S, Li Y, Ren S, Gu C, Li J. General fabrication of ordered nanocone arrays by one-step selective plasma etching. NANOTECHNOLOGY 2014; 25:115301. [PMID: 24556649 DOI: 10.1088/0957-4484/25/11/115301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
One-step selective direct current (DC) plasma etching technology is employed to fabricate large-area well-aligned nanocone arrays on various functional materials including semiconductor, insulator and metal. The cones have nanoscale apexes (∼2 nm) with high aspect ratios, which were achieved by a selective plasma etching process using only CH4 and H2 in a bias-assisted hot filament chemical vapor deposition (HFCVD) system without any masked process. The CH(3)(+) ions play a major role to etch the roughened surface into a conical structure under the auxiliary of H(+) ions. Randomly formed nano-carbon may act as an original mask on the smooth surface to initiate the following selective ions sputtering. Physical impinging of energetic ions onto the concave regions is predominant in comparison with the etching of convex parts on the surface, which is identified as the key mechanism for the formation of conical nanostructures. This one-step maskless plasma etching technology enables the universal formation of uniform nanocone structures on versatile substrates for many promising applications.
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Affiliation(s)
- Qiang Wang
- Department of Optics and Electronics Science, College of Science, Harbin Institute of Technology at Wei Hai, Wei Hai 264209, People's Republic of China
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Kim JH, Ko YH, Gong SH, Ko SM, Cho YH. Ultrafast single photon emitting quantum photonic structures based on a nano-obelisk. Sci Rep 2013; 3:2150. [PMID: 23828558 PMCID: PMC3701894 DOI: 10.1038/srep02150] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Accepted: 06/19/2013] [Indexed: 11/30/2022] Open
Abstract
A key issue in a single photon source is fast and efficient generation of a single photon flux with high light extraction efficiency. Significant progress toward high-efficiency single photon sources has been demonstrated by semiconductor quantum dots, especially using narrow bandgap materials. Meanwhile, there are many obstacles, which restrict the use of wide bandgap semiconductor quantum dots as practical single photon sources in ultraviolet-visible region, despite offering free space communication and miniaturized quantum information circuits. Here we demonstrate a single InGaN quantum dot embedded in an obelisk-shaped GaN nanostructure. The nano-obelisk plays an important role in eliminating dislocations, increasing light extraction, and minimizing a built-in electric field. Based on the nano-obelisks, we observed nonconventional narrow quantum dot emission and positive biexciton binding energy, which are signatures of negligible built-in field in single InGaN quantum dots. This results in efficient and ultrafast single photon generation in the violet color region.
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Affiliation(s)
- Je-Hyung Kim
- Department of Physics, Graduate School of Nanoscience & Technology (WCU), and KAIST Institute for NanoCentury, KAIST, Daejeon, 305-701, Republic of Korea
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Chen JY, Liou YT, Wei CM, Chen SH, Lin MT, Chen YF. Optically tunable and detectable magnetoelectric effects in the composite consisting of magnetic thin films and InGaN/GaN multiple quantum wells. OPTICS EXPRESS 2013; 21:19934-19942. [PMID: 24105539 DOI: 10.1364/oe.21.019934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
An optically tunable and detectable magnetoeletric (ME) effect has been discovered in the composite consisting of InGaN/GaN multiple quantum wells and magnetostrictive ferromagnetic Ni or FeCo thin films at room temperature. Due to the interactively optical and piezoelectric properties of nitride semiconductors, this composite provides an intriguing optically accessible system, in which the magnetoelectric effect can be both easily tuned and detected. The underlying mechanism can be well accounted for by the interplay among magnetostrictive, piezoelectric and optical transition. It thus offers a new paradigm to generate artificial material systems with magnetic/electric/optical inter-related/controllable properties.
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Zhang C, Wang K, Bai J, Wang S, Zhao W, Yang F, Gu C, Wang G. Nanopillar array with a λ/11 diameter fabricated by a kind of visible CW laser direct lithography system. NANOSCALE RESEARCH LETTERS 2013; 8:280. [PMID: 23759031 PMCID: PMC3693884 DOI: 10.1186/1556-276x-8-280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Accepted: 06/01/2013] [Indexed: 06/02/2023]
Abstract
Nanoscale functional structures are indispensable elements in many fields of modern science. In this paper, nanopillar array with a pillar diameter far smaller than Abbe's diffraction limit is realized by a new kind of continuous wave (CW) laser direct lithography technology. With atomic force microscopy technology, the average diameter of nanopillars on thin OIR906 photoresist film is about 65 nm and the smallest diameter is 48 nm, which is about 1/11 of the incident laser wavelength. Also, the influences of coma and astigmatism effects to the shape and size of nanopillar are numerically simulated by utilizing vector integral. As far as we know, it is the first time that nanopillar array is implemented by a donut-shaped 532-nm visible CW laser. The study presents a new, simple, inexpensive, and effective approach for nanopillar/pore array fabrication.
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Affiliation(s)
- Chen Zhang
- Institute of Photonics and Photo-technology, International Scientific and Technological Cooperation Base of Photoelectric Technology and Functional Materials and Application, Northwest University, 229 North Taibai Rd, Xi'an, 710069, People's Republic of China
- Department of Mechanical Engineering, University of South Carolina, 300 Main St., Columbia, SC, 29208, USA
| | - Kaige Wang
- Institute of Photonics and Photo-technology, International Scientific and Technological Cooperation Base of Photoelectric Technology and Functional Materials and Application, Northwest University, 229 North Taibai Rd, Xi'an, 710069, People's Republic of China
| | - Jintao Bai
- Institute of Photonics and Photo-technology, International Scientific and Technological Cooperation Base of Photoelectric Technology and Functional Materials and Application, Northwest University, 229 North Taibai Rd, Xi'an, 710069, People's Republic of China
| | - Shuang Wang
- Institute of Photonics and Photo-technology, International Scientific and Technological Cooperation Base of Photoelectric Technology and Functional Materials and Application, Northwest University, 229 North Taibai Rd, Xi'an, 710069, People's Republic of China
| | - Wei Zhao
- Department of Mechanical Engineering, University of South Carolina, 300 Main St., Columbia, SC, 29208, USA
| | - Fang Yang
- Department of Mechanical Engineering, University of South Carolina, 300 Main St., Columbia, SC, 29208, USA
| | - Changzhi Gu
- Institute of Physics, Chinese Academy of Sciences, 8 Zhongguancun 3rd South St, Beijing, 100190, People's Republic of China
| | - Guiren Wang
- Department of Mechanical Engineering, University of South Carolina, 300 Main St., Columbia, SC, 29208, USA
- Department of Physics, Northwest University, 229 North Taibai Rd, Xi'an, 710069, People's Republic of China
- Department of Biomedical Engineering Program, University of South Carolina, 300 Main St., Columbia, SC, 29208, USA
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Jiang B, Zhang C, Wang X, Xue F, Park MJ, Kwak JS, Xiao M. Effects of reduced exciton diffusion in InGaN/GaN multiple quantum well nanorods. OPTICS EXPRESS 2012; 20:13478-13487. [PMID: 22714375 DOI: 10.1364/oe.20.013478] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We investigate the effects of reduced exciton diffusion on the emission properties in InGaN/GaN multiple-quantum-well nanorods. Time-resolved photoluminescence spectra are recorded and compared in dry-etched InGaN/GaN nanorods and parent multiple quantum wells at various temperatures with carrier density in different regimes. Faster carrier recombination and absence of delayed rise in the emission dynamics are found in nanorods. Many effects, including surface damages and partial relaxation of the strain, may cause the faster recombination in nanorods. Together with these enhanced carrier recombination processes, the reduced exciton diffusion may induce the different temperature-dependent emission dynamics characterized by the delayed rise in time-resolved photoluminescence spectra.
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Affiliation(s)
- Bin Jiang
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, China
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Chen LY, Huang HH, Chang CH, Huang YY, Wu YR, Huang J. Investigation of the strain induced optical transition energy shift of the GaN nanorod light emitting diode arrays. OPTICS EXPRESS 2011; 19 Suppl 4:A900-A907. [PMID: 21747560 DOI: 10.1364/oe.19.00a900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Strain in the semiconductor light emitting layers has profound effect on the energy band structure and the optical properties of the light emitting diodes (LEDs). Here, we report the fabrication and characterization of GaN nanorod LED arrays. We found that the choice of nanorod passivation materials results in the variation of strain in the InGaN/GaN quantum wells, and thus the corresponding change of light emission properties. The results were further investigated by performing Raman measurement to understand the strain of nanorods with different passivation materials and by calculating the optical transition energy of the devices under the influence of strain-induced deformation potential and the piezoelectric polarization field.
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Affiliation(s)
- Liang-Yi Chen
- Graduate Institute of Photonics and Optoelectronics, National Taiwan University, 1, Roosevelt Road, Section 4, Taipei, 106, Taiwan
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Chen LY, Huang YY, Chang CH, Sun YH, Cheng YW, Ke MY, Chen CP, Huang J. High performance InGaN/GaN nanorod light emitting diode arrays fabricated by nanosphere lithography and chemical mechanical polishing processes. OPTICS EXPRESS 2010; 18:7664-7669. [PMID: 20588606 DOI: 10.1364/oe.18.007664] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We fabricated InGaN/GaN nanorod light emitting diode (LED) arrays using nanosphere lithography for nanorod formation, PECVD (plasma enhanced chemical vapor deposition) grown SiO(2) layer for sidewall passivation, and chemical mechanical polishing for uniform nanorod contact. The nano-device demonstrates a reverse current 4.77nA at -5V, an ideality factor 7.35, and an optical output intensity 6807mW/cm(2) at the injection current density 32A/cm(2) (20mA). Moreover, the investigation of the droop effect for such a nanorod LED array reveals that junction heating is responsible for the sharp decrease at the low current.
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Affiliation(s)
- Liang-Yi Chen
- Graduate Institute of Photonics and Optoelectronics, National Taiwan University, 1, Roosevelt Road, Section 4, Taipei, 106, Taiwan.
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