Structural and optical impacts of AlGaN undershells on coaxial GaInN/GaN multiple-quantum-shells nanowires

Lu Weifang; Terazawa Mizuki; Han Dong-Pyo; Sone Naoki; Goto Nanami; Iida Kazuyoshi; Murakami Hedeki; Iwaya Motoaki; Tekeuchi Tetsuya; Kamiyama Satoshi; Akasaki Isamu

doi:10.1515/nanoph-2019-0328

Nanophotonics (Nov 2019)

Structural and optical impacts of AlGaN undershells on coaxial GaInN/GaN multiple-quantum-shells nanowires

Lu Weifang,
Terazawa Mizuki,
Han Dong-Pyo,
Sone Naoki,
Goto Nanami,
Iida Kazuyoshi,
Murakami Hedeki,
Iwaya Motoaki,
Tekeuchi Tetsuya,
Kamiyama Satoshi,
Akasaki Isamu

Affiliations

Lu Weifang: Department of Materials Science and Engineering, Meijo University, 1-501 Shiogamaguchi, Tenpaku-ku, Nagoya, 468-8502, Japan, e-mail: [email protected]
Terazawa Mizuki: Department of Materials Science and Engineering, Meijo University, 1-501 Shiogamaguchi, Tenpaku-ku, Nagoya, 468-8502, Japan
Han Dong-Pyo: Department of Materials Science and Engineering, Meijo University, 1-501 Shiogamaguchi, Tenpaku-ku, Nagoya, 468-8502, Japan
Sone Naoki: Department of Materials Science and Engineering, Meijo University, 1-501 Shiogamaguchi, Tenpaku-ku, Nagoya, 468-8502, Japan
Goto Nanami: Department of Materials Science and Engineering, Meijo University, 1-501 Shiogamaguchi, Tenpaku-ku, Nagoya, 468-8502, Japan
Iida Kazuyoshi: Department of Materials Science and Engineering, Meijo University, 1-501 Shiogamaguchi, Tenpaku-ku, Nagoya, 468-8502, Japan
Murakami Hedeki: Department of Materials Science and Engineering, Meijo University, 1-501 Shiogamaguchi, Tenpaku-ku, Nagoya, 468-8502, Japan
Iwaya Motoaki: Department of Materials Science and Engineering, Meijo University, 1-501 Shiogamaguchi, Tenpaku-ku, Nagoya, 468-8502, Japan
Tekeuchi Tetsuya: Department of Materials Science and Engineering, Meijo University, 1-501 Shiogamaguchi, Tenpaku-ku, Nagoya, 468-8502, Japan
Kamiyama Satoshi: Department of Materials Science and Engineering, Meijo University, 1-501 Shiogamaguchi, Tenpaku-ku, Nagoya, 468-8502, Japan
Akasaki Isamu: Department of Materials Science and Engineering, Meijo University, 1-501 Shiogamaguchi, Tenpaku-ku, Nagoya, 468-8502, Japan

DOI: https://doi.org/10.1515/nanoph-2019-0328
Journal volume & issue: Vol. 9, no. 1
pp. 101 – 111

Abstract

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The superior crystalline quality of coaxial GaInN/GaN multiple-quantum shell (MQS) nanowires (NWs) was demonstrated by employing an AlGaN undershell during metal-organic chemical vapor deposition. Scanning transmission electron microscopy (STEM) results reveal that the NW structure consists of distinct GaInN/GaN regions on different positions of the NWs and the cores were dislocation-free. High-resolution atomic contrast STEM images verified the importance of AlGaN undershells in trapping the point defects diffused from n-core to MQSs (m-planes), as well as the improvement of the grown crystal quality on the apex region (c-planes). Time-integrated and time-resolved photoluminescence (PL) measurements were performed to clarify the mechanism of the emission within the coaxial GaInN/GaN MQS NWs. The improved internal quantum efficiency in the NW sample was attributed to the unique AlGaN undershell, which was able to suppress the point defects diffusion and reduce the dislocation densities on c-planes. Carrier lifetimes of 2.19 ns and 8.44 ns were derived from time-resolved PL decay curves for NW samples without and with the AlGaN undershell, respectively. Hence, the use of an AlGaN undershell exhibits promising improvement of optical properties for NW-based white and micro light-emitting diodes.

Published in Nanophotonics

ISSN: 2192-8606 (Print); 2192-8614 (Online)
Publisher: De Gruyter
Country of publisher: Germany
LCC subjects: Science: Physics
Website: https://www.degruyter.com/journal/key/nanoph/html#submit

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