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Vermeersch R, Jacopin G, Castioni F, Rouvière JL, García-Cristóbal A, Cros A, Pernot J, Daudin B. Ultrathin GaN quantum wells in AlN nanowires for UV-C emission. NANOTECHNOLOGY 2023; 34:275603. [PMID: 37023726 DOI: 10.1088/1361-6528/accaeb] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 04/06/2023] [Indexed: 06/19/2023]
Abstract
Molecular beam epitaxy growth and optical properties of GaN quantum disks in AlN nanowires were investigated, with the purpose of controlling the emission wavelength of AlN nanowire-based light emitting diodes. Besides GaN quantum disks with a thickness ranging from 1 to 4 monolayers, a special attention was paid to incomplete GaN disks exhibiting lateral confinement. Their emission consists of sharp lines which extend down to 215 nm, in the vicinity of AlN band edge. The room temperature cathodoluminescence intensity of an ensemble of GaN quantum disks embedded in AlN nanowires is about 20% of the low temperature value, emphasizing the potential of ultrathin/incomplete GaN quantum disks for deep UV emission.
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Affiliation(s)
- Rémy Vermeersch
- Univ. Grenoble Alpes, Grenoble INP, CNRS, Institut Néel , F-38000 Grenoble, France
- Univ. Grenoble Alpes, Grenoble INP, CEA, IRIG-PHELIQS, NPSC, 17 rue des martyrs, F-38000 Grenoble, France
| | - Gwénolé Jacopin
- Univ. Grenoble Alpes, Grenoble INP, CNRS, Institut Néel , F-38000 Grenoble, France
| | - Florian Castioni
- Univ. Grenoble Alpes, CEA, LETI, 17 rue des martyrs, F-38000 Grenoble, France
| | - Jean-Luc Rouvière
- Univ. Grenoble Alpes, Grenoble INP, CEA, IRIG-MEM, LEMMA, 17 rue des martyrs, F-38000 Grenoble, France
| | | | - Ana Cros
- Materials Science Institute (ICMUV), University of Valencia, ES-46071 Valencia, Spain
| | - Julien Pernot
- Univ. Grenoble Alpes, Grenoble INP, CNRS, Institut Néel , F-38000 Grenoble, France
| | - Bruno Daudin
- Univ. Grenoble Alpes, Grenoble INP, CEA, IRIG-PHELIQS, NPSC, 17 rue des martyrs, F-38000 Grenoble, France
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AlGaN Quantum Disk Nanorods with Efficient UV-B Emission Grown on Si(111) Using Molecular Beam Epitaxy. NANOMATERIALS 2022; 12:nano12142508. [PMID: 35889730 PMCID: PMC9319290 DOI: 10.3390/nano12142508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 07/20/2022] [Accepted: 07/20/2022] [Indexed: 11/17/2022]
Abstract
AlGaN nanorods have attracted increasing amounts of attention for use in ultraviolet (UV) optoelectronic devices. Here, self-assembled AlGaN nanorods with embedding quantum disks (Qdisks) were grown on Si(111) using plasma-assisted molecular beam epitaxy (PA-MBE). The morphology and quantum construction of the nanorods were investigated and well-oriented and nearly defect-free nanorods were shown to have a high density of about 2 × 1010 cm−2. By controlling the substrate temperature and Al/Ga ratio, the emission wavelengths of the nanorods could be adjusted from 276 nm to 330 nm. By optimizing the structures and growth parameters of the Qdisks, a high internal quantum efficiency (IQE) of the AlGaN Qdisk nanorods of up to 77% was obtained at 305 nm, which also exhibited a shift in the small emission wavelength peak with respect to the increasing temperatures during the PL measurements.
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Radiometric characterisation of light sources used in analytical chemistry - A review. Anal Chim Acta 2020; 1123:113-127. [PMID: 32507235 DOI: 10.1016/j.aca.2020.04.048] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 03/30/2020] [Accepted: 04/20/2020] [Indexed: 11/22/2022]
Abstract
Light sources are an indispensable component of an overwhelmingly large number of analytical methods. Radiometric characterisation of light sources in analytical chemistry is therefore of fundamental importance. This review presents up to date knowledge on methods to characterise radiometric properties of light sources in terms of radiometric power, irradiance, brightness, luminous efficacy, luminous efficiency and emission spectra, all of which are crucial parameters for their use in analytical chemistry. Special attention is paid to radiometric characterisation of new generations of light sources with focus on miniaturised and low-cost light sources suitable for portable analytical instrumentation. Miniaturised light sources, especially new generations of solid-state light sources including solution processable quantum dot light emitting diodes (QLEDs), organic LEDs (OLEDs) as well as conventional LEDs and lasers, are radiometrically characterised through various spectrophotometric, actinometric as well as new facile radiometric methods. Although the areas of analytical use of new light sources including QLEDs, OLEDs as well as other important light sources such as deep ultraviolet (DUV) and infrared LEDs in analytical chemistry are yet to reach their potential, their radiometric characterisation opens future options for their wider deployment in analytical chemistry.
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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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Ra YH, Lee CR. Core-Shell Tunnel Junction Nanowire White-Light-Emitting Diode. NANO LETTERS 2020; 20:4162-4168. [PMID: 32105489 DOI: 10.1021/acs.nanolett.0c00420] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
We have demonstrated a new class of phosphor-free white LEDs with the use of tunnel junction structure in nonpolar core-shell InGaN nanowires. It is confirmed that the tunnel junction based nanowire LEDs can eliminate the use of the resistive p-GaN:Mg contact layer, leading to significantly enhanced hole injection and dramatically reduced voltage loss. The nonpolar core-shell nanowire heterostructure showed the enhanced carrier injection efficiency through the widened shell n-GaN contact area. The TEM analysis verified that the core-shell Al tunnel junction layers were uniformly grown on nonpolar surfaces of the GaN wurtzite crystal nanowire structure. We have also showed the monolithic integration of multiple-color emission on a single chip by using the multiple-stacked tunnel junction core-shell nanowire heterostructure. Compared to the conventional film based quantum well LEDs, the demonstrated nonpolar core-shell tunnel junction nanowire LEDs will be a very promising candidate for future solid-state lighting applications as well as phosphor-free white LEDs.
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Affiliation(s)
- Yong-Ho Ra
- Optic & Electronic Component Material Center, Korea Institute of Ceramic Engineering & Technology, Jinju 52851, Republic of Korea
| | - Cheul-Ro Lee
- School of Advanced Materials Engineering, Engineering College, Chonbuk National University, Deokjin-dong 664-14, Jeonju 54896, Republic of Korea
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Velpula RT, Jain B, Philip MR, Nguyen HD, Wang R, Nguyen HPT. Epitaxial Growth and Characterization of AlInN-Based Core-Shell Nanowire Light Emitting Diodes Operating in the Ultraviolet Spectrum. Sci Rep 2020; 10:2547. [PMID: 32054926 PMCID: PMC7018839 DOI: 10.1038/s41598-020-59442-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 01/17/2020] [Indexed: 11/09/2022] Open
Abstract
We report the demonstration of the first axial AlInN ultraviolet core-shell nanowire light-emitting diodes with highly stable emission in the ultraviolet wavelength range. During epitaxial growth of the AlInN layer, an AlInN shell is spontaneously formed, resulting in reduced nonradiative recombination on the nanowire surface. The AlInN nanowires exhibit a high internal quantum efficiency of ~52% at room temperature for emission at 295 nm. The peak emission wavelength can be varied from 290 nm to 355 nm by changing the growth conditions. Moreover, significantly strong transverse magnetic (TM) polarized emission is recorded, which is ~4 times stronger than the transverse electric (TE) polarized light at 295 nm. This study provides an alternative approach for the fabrication of new types of high-performance ultraviolet light emitters.
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Affiliation(s)
- Ravi Teja Velpula
- Department of Electrical and Computer Engineering, New Jersey Institute of Technology, 323 Dr Martin Luther King Jr Boulevard, Newark, New Jersey, 07102, United States
| | - Barsha Jain
- Department of Electrical and Computer Engineering, New Jersey Institute of Technology, 323 Dr Martin Luther King Jr Boulevard, Newark, New Jersey, 07102, United States
| | - Moab Rajan Philip
- Department of Electrical and Computer Engineering, New Jersey Institute of Technology, 323 Dr Martin Luther King Jr Boulevard, Newark, New Jersey, 07102, United States
| | - Hoang Duy Nguyen
- Institute of Chemical Technology, Vietnam Academy of Science and Technology, 1 Mac Dinh Chi Street, District 1, Ho Chi Minh City, 700000, Vietnam.
| | - Renjie Wang
- Department of Engineering Physics, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4L7, Canada
| | - Hieu Pham Trung Nguyen
- Department of Electrical and Computer Engineering, New Jersey Institute of Technology, 323 Dr Martin Luther King Jr Boulevard, Newark, New Jersey, 07102, United States.
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AlGaN Nanowires for Ultraviolet Light-Emitting: Recent Progress, Challenges, and Prospects. MICROMACHINES 2020; 11:mi11020125. [PMID: 31979274 PMCID: PMC7074201 DOI: 10.3390/mi11020125] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 01/19/2020] [Accepted: 01/22/2020] [Indexed: 12/12/2022]
Abstract
In this paper, we discuss the recent progress made in aluminum gallium nitride (AlGaN) nanowire ultraviolet (UV) light-emitting diodes (LEDs). The AlGaN nanowires used for such LED devices are mainly grown by molecular beam epitaxy (MBE) and metalorganic chemical vapor deposition (MOCVD); and various foreign substrates/templates have been investigated. Devices on Si so far exhibit the best performance, whereas devices on metal and graphene have also been investigated to mitigate various limitations of Si substrate, e.g., the UV light absorption. Moreover, patterned growth techniques have also been developed to grow AlGaN nanowire UV LED structures, in order to address issues with the spontaneously formed nanowires. Furthermore, to reduce the quantum confined Stark effect (QCSE), nonpolar AlGaN nanowire UV LEDs exploiting the nonpolar nanowire sidewalls have been demonstrated. With these recent developments, the prospects, together with the general challenges of AlGaN nanowire UV LEDs, are discussed in the end.
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Wu Y, Xu J, Jiang M, Zhou X, Wan P, Kan C. Tailoring the electroluminescence of a single microwire based heterojunction diode using Ag nanowires deposition. CrystEngComm 2020. [DOI: 10.1039/d0ce00049c] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A single Ga-doped ZnO microwire covered by Ag nanowires (AgNWs@ZnO:Ga MW) was utilized to construct a promising ultraviolet light source, with p-GaN serving as a hole injection layer.
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Affiliation(s)
- Yuting Wu
- College of Science
- Nanjing University of Aeronautics and Astronautics
- Nanjing
- China
| | - Juan Xu
- College of Science
- Nanjing University of Aeronautics and Astronautics
- Nanjing
- China
| | - Mingming Jiang
- College of Science
- Nanjing University of Aeronautics and Astronautics
- Nanjing
- China
- Key Laboratory for Intelligent Nano Materials and Devices (MOE)
| | - Xiangbo Zhou
- College of Science
- Nanjing University of Aeronautics and Astronautics
- Nanjing
- China
| | - Peng Wan
- College of Science
- Nanjing University of Aeronautics and Astronautics
- Nanjing
- China
| | - Caixia Kan
- College of Science
- Nanjing University of Aeronautics and Astronautics
- Nanjing
- China
- Key Laboratory for Intelligent Nano Materials and Devices (MOE)
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Siladie AM, Jacopin G, Cros A, Garro N, Robin E, Caliste D, Pochet P, Donatini F, Pernot J, Daudin B. Mg and In Codoped p-type AlN Nanowires for pn Junction Realization. NANO LETTERS 2019; 19:8357-8364. [PMID: 31724873 DOI: 10.1021/acs.nanolett.9b01394] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Efficient, mercury-free deep ultraviolet (DUV) light-emitting diodes (LEDs) are becoming a crucial challenge for many applications such as water purification. For decades, the poor p-type doping and difficult current injection of Al-rich AlGaN-based DUV LEDs have limited their efficiency and therefore their use. We present here the significant increase in AlN p-doping thanks to Mg/In codoping, which leads to an order of magnitude higher Mg solubility limit in AlN nanowires (NWs). Optimal electrical activation of acceptor impurities has been further achieved by electron irradiation, resulting in tunnel conduction through the AlN NW p-n junction. The proposed theoretical scenario to account for enhanced Mg incorporation involves an easy ionization of In-vacancy complex associated with a negative charging of Mg in In vicinity. This leads to favored incorporation of negatively charged Mg into the AlN matrix, opening the path to the realization of highly efficient NW-based LEDs in the DUV range.
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Affiliation(s)
| | - Gwénolé Jacopin
- Grenoble INP, Institut Néel , University Grenoble Alpes, CNRS , 38000 Grenoble , France
| | - Ana Cros
- Institute of Materials Science , Universidad de Valencia , Valencia , Spain
| | - Nuria Garro
- Institute of Materials Science , Universidad de Valencia , Valencia , Spain
| | - Eric Robin
- IRIG-MEM, LEMMA , University Grenoble Alpes, CEA , F-38000 Grenoble , France
| | - Damien Caliste
- IRIG-MEM, L-SIM , University Grenoble Alpes, CEA , F-38000 Grenoble , France
| | - Pascal Pochet
- IRIG-MEM, L-SIM , University Grenoble Alpes, CEA , F-38000 Grenoble , France
| | - Fabrice Donatini
- Grenoble INP, Institut Néel , University Grenoble Alpes, CNRS , 38000 Grenoble , France
| | - Julien Pernot
- Grenoble INP, Institut Néel , University Grenoble Alpes, CNRS , 38000 Grenoble , France
| | - Bruno Daudin
- IRIG-PHELIQS, NPSC , University Grenoble Alpes, CEA , 38000 Grenoble , France
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Barrigón E, Heurlin M, Bi Z, Monemar B, Samuelson L. Synthesis and Applications of III-V Nanowires. Chem Rev 2019; 119:9170-9220. [PMID: 31385696 DOI: 10.1021/acs.chemrev.9b00075] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Low-dimensional semiconductor materials structures, where nanowires are needle-like one-dimensional examples, have developed into one of the most intensely studied fields of science and technology. The subarea described in this review is compound semiconductor nanowires, with the materials covered limited to III-V materials (like GaAs, InAs, GaP, InP,...) and III-nitride materials (GaN, InGaN, AlGaN,...). We review the way in which several innovative synthesis methods constitute the basis for the realization of highly controlled nanowires, and we combine this perspective with one of how the different families of nanowires can contribute to applications. One reason for the very intense research in this field is motivated by what they can offer to main-stream semiconductors, by which ultrahigh performing electronic (e.g., transistors) and photonic (e.g., photovoltaics, photodetectors or LEDs) technologies can be merged with silicon and CMOS. Other important aspects, also covered in the review, deals with synthesis methods that can lead to dramatic reduction of cost of fabrication and opportunities for up-scaling to mass production methods.
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Affiliation(s)
- Enrique Barrigón
- Division of Solid State Physics and NanoLund , Lund University , Box 118, 22100 Lund , Sweden
| | - Magnus Heurlin
- Division of Solid State Physics and NanoLund , Lund University , Box 118, 22100 Lund , Sweden.,Sol Voltaics AB , Scheelevägen 63 , 223 63 Lund , Sweden
| | - Zhaoxia Bi
- Division of Solid State Physics and NanoLund , Lund University , Box 118, 22100 Lund , Sweden
| | - Bo Monemar
- Division of Solid State Physics and NanoLund , Lund University , Box 118, 22100 Lund , Sweden
| | - Lars Samuelson
- Division of Solid State Physics and NanoLund , Lund University , Box 118, 22100 Lund , Sweden
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11
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Zhao S, Wang R, Chu S, Mi Z. Molecular Beam Epitaxy of III-Nitride Nanowires: Emerging Applications From Deep-Ultraviolet Light Emitters and Micro-LEDs to Artificial Photosynthesis. IEEE NANOTECHNOLOGY MAGAZINE 2019. [DOI: 10.1109/mnano.2019.2891370] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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12
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Zhang L, Guo YN, Yan JC, Wu QQ, Wei XC, Wang JX, Li JM. Deep ultraviolet light-emitting diodes with improved performance via nanoporous AlGaN template. OPTICS EXPRESS 2019; 27:4917-4926. [PMID: 30876101 DOI: 10.1364/oe.27.004917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 01/19/2019] [Indexed: 06/09/2023]
Abstract
We report the performance enhancement of AlGaN-based deep ultraviolet light-emitting diodes (DUV LEDs) using AlGaN nanoporous template (NPT). The NPT was fabricated by the electrochemical etching method and served as the dislocation filtering layer and strain relieving layer. The n-AlGaN laterally regrown on NPT showed reduced dislocation density and mitigated compressive strain comparing with that on the as-grown template (AGT). A 23% improvement of internal quantum efficiency was achieved for the multiple quantum wells thereon. Moreover, the nanopores in the NPT transformed into elongated air voids during high temperature growth process, which could facilitate the escaping of photons by scattering and thus improve the light extraction efficiency. As a consequence, the DUV LED based on NPT demonstrated an increase of the light outpower by 50% at 20 mA than that on AGT.
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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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14
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Deitz JI, Sarwar ATMG, Carnevale SD, Grassman TJ, Myers RC, McComb DW. Nano-Cathodoluminescence Measurement of Asymmetric Carrier Trapping and Radiative Recombination in GaN and InGaN Quantum Disks. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2018; 24:93-98. [PMID: 29699596 DOI: 10.1017/s143192761800017x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The ability to characterize recombination and carrier trapping processes in group-III nitride-based nanowires is vital to further improvements in their overall efficiencies. While advances in scanning transmission electron microscope (STEM)-based cathodoluminescence (CL) have offered some insight into nanowire behavior, inconsistencies in nanowire emission along with CL detector limitations have resulted in the incomplete understanding in nanowire emission processes. Here, two nanowire heterostructures were explored with STEM-CL: a polarization-graded AlGaN nanowire light-emitting diode (LED) with a GaN quantum disk and a polarization-graded AlGaN nanowire with three different InGaN quantum disks. Most nanowires explored in this study did not emit. For the wires that did emit in both structures, they exhibited asymmetrical emission consistent with the polarization-induced electric fields in the barrier regions of the nano-LEDs. In the AlGaN/InGaN sample, two of the quantum disks exhibited no emission potentially due to the three-dimensional landscape of the sample or due to limitations in the CL detection.
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Affiliation(s)
- Julia I Deitz
- 1Department of Materials Science and Engineering,The Ohio State University,Columbus,OH 43210,USA
| | - A T M Golam Sarwar
- 2Department of Electrical and Computer Engineering,The Ohio State University,Columbus,OH 43210,USA
| | - Santino D Carnevale
- 2Department of Electrical and Computer Engineering,The Ohio State University,Columbus,OH 43210,USA
| | - Tyler J Grassman
- 1Department of Materials Science and Engineering,The Ohio State University,Columbus,OH 43210,USA
| | - Roberto C Myers
- 1Department of Materials Science and Engineering,The Ohio State University,Columbus,OH 43210,USA
| | - David W McComb
- 1Department of Materials Science and Engineering,The Ohio State University,Columbus,OH 43210,USA
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15
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Deep-Ultraviolet AlGaN/AlN Core-Shell Multiple Quantum Wells on AlN Nanorods via Lithography-Free Method. Sci Rep 2018; 8:935. [PMID: 29343856 PMCID: PMC5772499 DOI: 10.1038/s41598-017-19047-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 12/18/2017] [Indexed: 11/17/2022] Open
Abstract
We report deep ultraviolet (UVC) emitting core-shell-type AlGaN/AlN multiple quantum wells (MQWs) on the AlN nanorods which are prepared by catalyst/lithography free process. The MQWs are grown on AlN nanorods on a sapphire substrate by polarity-selective epitaxy and etching (PSEE) using high-temperature metal organic chemical vapor deposition. The AlN nanorods prepared through PSEE have a low dislocation density because edge dislocations are bent toward neighboring N-polar AlN domains. The core–shell-type MQWs grown on AlN nanorods have three crystallographic orientations, and the final shape of the grown structure is explained by a ball-and-stick model. The photoluminescence (PL) intensity of MQWs grown on AlN nanorods is approximately 40 times higher than that of MQWs simultaneously grown on a planar structure. This result can be explained by increased internal quantum efficiency, large active volume, and increase in light extraction efficiency based on the examination in this study. Among those effects, the increase of active volume on AlN nanorods is considered to be the main reason for the enhancement of the PL intensity.
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16
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Bengoechea-Encabo A, Albert S, Müller M, Xie MY, Veit P, Bertram F, Sanchez-Garcia MA, Zúñiga-Pérez J, de Mierry P, Christen J, Calleja E. Selective area growth of AlN/GaN nanocolumns on (0001) and (11-22) GaN/sapphire for semi-polar and non-polar AlN pseudo-templates. NANOTECHNOLOGY 2017; 28:365704. [PMID: 28604369 DOI: 10.1088/1361-6528/aa78e6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Despite the strong interest in optoelectronic devices working in the deep ultraviolet range, no suitable low cost, large-area, high-quality AlN substrates have been available up to now. The aim of this work is the selective area growth of AlN nanocolumns by plasma assisted molecular beam epitaxy on polar (0001) and semi-polar (11-22) GaN/sapphire templates. The resulting AlN nanocolumns are vertically oriented with semi-polar {1-103} top facets when grown on (0001) GaN/sapphire, or oriented at 58° from the template normal and exposing {1-100} non-polar top facets when growing on (11-22) GaN/sapphire, in both cases reaching filling factors ≥80%. In these kinds of arrays each nanostructure could function as a building block for an individual nano-device or, due to the large filling factor values, the overall array top surfaces could be seen as a quasi (semi-polar or non-polar) AlN pseudo-template.
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Affiliation(s)
- A Bengoechea-Encabo
- ISOM and Dept. Ingeniería Electrónica, ETSI Telecomunicación, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, E-28040 Madrid, Spain
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18
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Laleyan DA, Zhao S, Woo SY, Tran HN, Le HB, Szkopek T, Guo H, Botton GA, Mi Z. AlN/h-BN Heterostructures for Mg Dopant-Free Deep Ultraviolet Photonics. NANO LETTERS 2017; 17:3738-3743. [PMID: 28471682 DOI: 10.1021/acs.nanolett.7b01068] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Aluminum-rich AlGaN is the ideal material system for emerging solid-state deep-ultraviolet (DUV) light sources. Devices operating in the near-UV spectral range have been realized; to date, however, the achievement of high-efficiency light-emitting diodes (LEDs) operating in the UV-C band (200-280 nm specifically) has been hindered by the extremely inefficient p-type conduction in AlGaN and the lack of DUV-transparent conductive electrodes. Here, we show that these critical challenges can be addressed by Mg dopant-free Al(Ga)N/h-BN nanowire heterostructures. By exploiting the acceptor-like boron vacancy formation, we have demonstrated that h-BN can function as a highly conductive, DUV-transparent electrode; the hole concentration is ∼1020 cm-3 at room temperature, which is 10 orders of magnitude higher than that previously measured for Mg-doped AlN epilayers. We have further demonstrated the first Al(Ga)N/h-BN LED, which exhibits strong emission at ∼210 nm. This work also reports the first achievement of Mg-free III-nitride LEDs that can exhibit high electrical efficiency (80% at 20 A/cm2).
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Affiliation(s)
- David Arto Laleyan
- Department of Electrical and Computer Engineering, McGill University , 3480 University Street, Montreal, Quebec H3A 0E9, Canada
- Department of Electrical Engineering and Computer Science, Center for Photonics and Multiscale Nanomaterials, University of Michigan , 1301 Beal Avenue, Ann Arbor, Michigan 48109, United States
| | - Songrui Zhao
- 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, McMaster University , 1280 Main Street W, Hamilton, Ontario L8S 4M1, Canada
| | - Hong Nhung Tran
- Department of Electrical and Computer Engineering, McGill University , 3480 University Street, Montreal, Quebec H3A 0E9, Canada
| | - Huy Binh Le
- Department of Electrical and Computer Engineering, McGill University , 3480 University Street, Montreal, Quebec H3A 0E9, Canada
| | - Thomas Szkopek
- Department of Electrical and Computer Engineering, McGill University , 3480 University Street, Montreal, Quebec H3A 0E9, Canada
| | - Hong Guo
- Department of Physics, McGill University , 3600 University Street, Montreal, Quebec H3A 2T8, Canada
| | - Gianluigi A Botton
- Department of Materials Science and Engineering, Canadian Centre for Electron Microscopy, McMaster University , 1280 Main Street W, Hamilton, Ontario L8S 4M1, Canada
| | - Zetian Mi
- Department of Electrical and Computer Engineering, McGill University , 3480 University Street, Montreal, Quebec H3A 0E9, Canada
- Department of Electrical Engineering and Computer Science, Center for Photonics and Multiscale Nanomaterials, University of Michigan , 1301 Beal Avenue, Ann Arbor, Michigan 48109, United States
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19
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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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20
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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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21
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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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22
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Ra YH, Wang R, Woo SY, Djavid M, Sadaf SM, Lee J, Botton GA, Mi Z. Full-Color Single Nanowire Pixels for Projection Displays. NANO LETTERS 2016; 16:4608-15. [PMID: 27332859 DOI: 10.1021/acs.nanolett.6b01929] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Multicolor single InGaN/GaN dot-in-nanowire light emitting diodes (LEDs) were fabricated on the same substrate using selective area epitaxy. It is observed that the structural and optical properties of InGaN/GaN quantum dots depend critically on nanowire diameters. Photoluminescence emission of single InGaN/GaN dot-in-nanowire structures exhibits a consistent blueshift with increasing nanowire diameter. This is explained by the significantly enhanced indium (In) incorporation for nanowires with small diameters, due to the more dominant contribution for In incorporation from the lateral diffusion of In adatoms. Single InGaN/GaN nanowire LEDs with emission wavelengths across nearly the entire visible spectral were demonstrated on a single chip by varying the nanowire diameters. Such nanowire LEDs also exhibit superior electrical performance, with a turn-on voltage ∼2 V and negligible leakage current under reverse bias. The monolithic integration of full-color LEDs on a single chip, coupled with the capacity to tune light emission characteristics at the single nanowire level, provides an unprecedented approach to realize ultrasmall and efficient projection display, smart lighting, and on-chip spectrometer.
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Affiliation(s)
- Yong-Ho Ra
- Department of Electrical and Computer Engineering, McGill University , 3480 University Street, Montreal, Quebec H3A 0E9, Canada
| | - Renjie Wang
- 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, McMaster University , 1280 Main Street West, Hamilton, Ontario L8S 4M1, Canada
| | - Mehrdad Djavid
- Department of Electrical and Computer Engineering, McGill University , 3480 University Street, Montreal, Quebec H3A 0E9, Canada
| | - Sharif Md Sadaf
- Department of Electrical and Computer Engineering, McGill University , 3480 University Street, Montreal, Quebec H3A 0E9, Canada
| | - Jaesoong Lee
- Nano Electronics Lab, Samsung Advanced Institute of Technology , Suwon-si, Gyeonggi-do 443-803, Korea
| | - Gianluigi A Botton
- Department of Materials Science and Engineering, Canadian Centre for Electron Microscopy, McMaster University , 1280 Main Street West, Hamilton, Ontario L8S 4M1, Canada
| | - Zetian Mi
- Department of Electrical and Computer Engineering, McGill University , 3480 University Street, Montreal, Quebec H3A 0E9, Canada
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23
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Mahbub P, Nesterenko PN. Application of photo degradation for remediation of cyclic nitramine and nitroaromatic explosives. RSC Adv 2016. [DOI: 10.1039/c6ra12565d] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Photo degradation is a rapid and safe remediation process and advances in continuous-flow photochemistry can scale-up yields of photo degradation.
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Affiliation(s)
- P. Mahbub
- Australian Centre for Research on Separation Science
- School of Physical Sciences
- University of Tasmania
- Hobart 7001
- Australia
| | - P. N. Nesterenko
- Australian Centre for Research on Separation Science
- School of Physical Sciences
- University of Tasmania
- Hobart 7001
- Australia
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