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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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Zhao S, Connie AT, Dastjerdi MHT, Kong XH, Wang Q, Djavid M, Sadaf S, Liu XD, Shih I, Guo H, Mi Z. Aluminum nitride nanowire light emitting diodes: Breaking the fundamental bottleneck of deep ultraviolet light sources. Sci Rep 2015; 5:8332. [PMID: 25684335 PMCID: PMC4329565 DOI: 10.1038/srep08332] [Citation(s) in RCA: 158] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 01/05/2015] [Indexed: 12/24/2022] Open
Abstract
Despite broad interest in aluminum gallium nitride (AlGaN) optoelectronic devices for deep ultraviolet (DUV) applications, the performance of conventional Al(Ga)N planar devices drastically decays when approaching the AlN end, including low internal quantum efficiencies (IQEs) and high device operation voltages. Here we show that these challenges can be addressed by utilizing nitrogen (N) polar Al(Ga)N nanowires grown directly on Si substrate. By carefully tuning the synthesis conditions, a record IQE of 80% can be realized with N-polar AlN nanowires, which is nearly ten times higher compared to high quality planar AlN. The first 210 nm emitting AlN nanowire light emitting diodes (LEDs) were achieved, with a turn on voltage of about 6 V, which is significantly lower than the commonly observed 20 – 40 V. This can be ascribed to both efficient Mg doping by controlling the nanowire growth rate and N-polarity induced internal electrical field that favors hole injection. In the end, high performance N-polar AlGaN nanowire LEDs with emission wavelengths covering the UV-B/C bands were also demonstrated.
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Affiliation(s)
- S Zhao
- Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, Quebec, Canada H3A 0E9
| | - A T Connie
- Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, Quebec, Canada H3A 0E9
| | - M H T Dastjerdi
- Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, Quebec, Canada H3A 0E9
| | - X H Kong
- Department of Physics, McGill University, 3600 University Street, Montreal, Quebec, Canada H3A 2T8
| | - Q Wang
- Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, Quebec, Canada H3A 0E9
| | - M Djavid
- Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, Quebec, Canada H3A 0E9
| | - S Sadaf
- Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, Quebec, Canada H3A 0E9
| | - X D Liu
- Facility for Electron Microscopy Research, McGill University, 3640 University Street, Montreal, Quebec H3A 0C7
| | - I Shih
- Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, Quebec, Canada H3A 0E9
| | - H Guo
- Department of Physics, McGill University, 3600 University Street, Montreal, Quebec, Canada H3A 2T8
| | - Z Mi
- Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, Quebec, Canada H3A 0E9
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Kim KH, An HM, Kim HD, Kim TG. Transparent conductive oxide films mixed with gallium oxide nanoparticle/single-walled carbon nanotube layer for deep ultraviolet light-emitting diodes. NANOSCALE RESEARCH LETTERS 2013; 8:507. [PMID: 24295342 PMCID: PMC3879035 DOI: 10.1186/1556-276x-8-507] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Accepted: 11/18/2013] [Indexed: 06/02/2023]
Abstract
We propose a transparent conductive oxide electrode scheme of gallium oxide nanoparticle mixed with a single-walled carbon nanotube (Ga2O3 NP/SWNT) layer for deep ultraviolet light-emitting diodes using spin and dipping methods. We investigated the electrical, optical and morphological properties of the Ga2O3 NP/SWNT layers by increasing the thickness of SWNTs via multiple dipping processes. Compared with the undoped Ga2O3 films (current level 9.9 × 10-9 A @ 1 V, transmittance 68% @ 280 nm), the current level flowing in the Ga2O3 NP/SWNT increased by approximately 4 × 105 times and the transmittance improved by 9% after 15 times dip-coating (current level 4 × 10-4 A at 1 V; transmittance 77.0% at 280 nm). These improvements result from both native high transparency of Ga2O3 NPs and high conductivity and effective current spreading of SWNTs.
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Affiliation(s)
- Kyoeng Heon Kim
- School of Electrical Engineering, Korea University, Seoul 136-713, Korea
| | - Ho-Myoung An
- Department of Digital Electronics, Osan College, Osan-si 447-749, Korea
| | - Hee-Dong Kim
- School of Electrical Engineering, Korea University, Seoul 136-713, Korea
| | - Tae Geun Kim
- School of Electrical Engineering, Korea University, Seoul 136-713, Korea
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