Abstract
Green-light-emitting InGaN/GaN multiple quantum wells (MQWs) with high luminescent efficiency were grown by metalorganic chemical vapour deposition (MOCVD). The microstructure of the sample was studied by high-resolution transmission electron microscopy (HRTEM) and high-resolution x-ray diffraction, while its optical behaviour was analysed in great detail by a variety of photoluminescence methods. Two InGaN-related peaks that were clearly found in the photoluminescence (PL) spectrum are assigned to quasi-quantum dots (516nm) and the InGaN matrix (450nm), respectively, due to a strong phase separation observed by HRTEM. Except for the strong indium aggregation regions (511meV of Stokes shift), slight composition fluctuations were also observed in the InGaN matrix, which were speculated from an 'S-shaped' transition and a Stokes shift of 341meV. Stronger carrier localization and an internal quantum efficiency of the dot-related emission (21.5%), higher than the InGaN-matrix related emission (7.5%), was demonstrated. Additionally, a shorter lifetime and 'two-component' PL decay were found for the low-indium-content regions (matrix). Thus, the carrier transport process within quantum wells is suggested to drift from the low-In-content matrix to the high-In-content dots, resulting in the enhanced luminescence efficiency of the green light emission.
| Original language | English |
|---|---|
| Article number | 020 |
| Pages (from-to) | 3734-3739 |
| Number of pages | 6 |
| Journal | Nanotechnology |
| Volume | 17 |
| Issue number | 15 |
| DOIs | |
| Publication status | Published - 2006 Aug 14 |
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All Science Journal Classification (ASJC) codes
- Bioengineering
- Chemistry(all)
- Materials Science(all)
- Mechanics of Materials
- Mechanical Engineering
- Electrical and Electronic Engineering
Cite this
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Origins of efficient green light emission in phase-separated InGaN quantum wells. / Lai, Yen Lin; Liu, Chuan-Pu; Lin, Yung Hsiang; Hsueh, Tao Hung; Lin, Ray Ming; Lyu, Dong Yuan; Peng, Zhao Xiang; Lin, Tai Yuan.
In: Nanotechnology, Vol. 17, No. 15, 020, 14.08.2006, p. 3734-3739.Research output: Contribution to journal › Article
TY - JOUR
T1 - Origins of efficient green light emission in phase-separated InGaN quantum wells
AU - Lai, Yen Lin
AU - Liu, Chuan-Pu
AU - Lin, Yung Hsiang
AU - Hsueh, Tao Hung
AU - Lin, Ray Ming
AU - Lyu, Dong Yuan
AU - Peng, Zhao Xiang
AU - Lin, Tai Yuan
PY - 2006/8/14
Y1 - 2006/8/14
N2 - Green-light-emitting InGaN/GaN multiple quantum wells (MQWs) with high luminescent efficiency were grown by metalorganic chemical vapour deposition (MOCVD). The microstructure of the sample was studied by high-resolution transmission electron microscopy (HRTEM) and high-resolution x-ray diffraction, while its optical behaviour was analysed in great detail by a variety of photoluminescence methods. Two InGaN-related peaks that were clearly found in the photoluminescence (PL) spectrum are assigned to quasi-quantum dots (516nm) and the InGaN matrix (450nm), respectively, due to a strong phase separation observed by HRTEM. Except for the strong indium aggregation regions (511meV of Stokes shift), slight composition fluctuations were also observed in the InGaN matrix, which were speculated from an 'S-shaped' transition and a Stokes shift of 341meV. Stronger carrier localization and an internal quantum efficiency of the dot-related emission (21.5%), higher than the InGaN-matrix related emission (7.5%), was demonstrated. Additionally, a shorter lifetime and 'two-component' PL decay were found for the low-indium-content regions (matrix). Thus, the carrier transport process within quantum wells is suggested to drift from the low-In-content matrix to the high-In-content dots, resulting in the enhanced luminescence efficiency of the green light emission.
AB - Green-light-emitting InGaN/GaN multiple quantum wells (MQWs) with high luminescent efficiency were grown by metalorganic chemical vapour deposition (MOCVD). The microstructure of the sample was studied by high-resolution transmission electron microscopy (HRTEM) and high-resolution x-ray diffraction, while its optical behaviour was analysed in great detail by a variety of photoluminescence methods. Two InGaN-related peaks that were clearly found in the photoluminescence (PL) spectrum are assigned to quasi-quantum dots (516nm) and the InGaN matrix (450nm), respectively, due to a strong phase separation observed by HRTEM. Except for the strong indium aggregation regions (511meV of Stokes shift), slight composition fluctuations were also observed in the InGaN matrix, which were speculated from an 'S-shaped' transition and a Stokes shift of 341meV. Stronger carrier localization and an internal quantum efficiency of the dot-related emission (21.5%), higher than the InGaN-matrix related emission (7.5%), was demonstrated. Additionally, a shorter lifetime and 'two-component' PL decay were found for the low-indium-content regions (matrix). Thus, the carrier transport process within quantum wells is suggested to drift from the low-In-content matrix to the high-In-content dots, resulting in the enhanced luminescence efficiency of the green light emission.
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U2 - 10.1088/0957-4484/17/15/020
DO - 10.1088/0957-4484/17/15/020
M3 - Article
VL - 17
SP - 3734
EP - 3739
JO - Nanotechnology
JF - Nanotechnology
SN - 0957-4484
IS - 15
M1 - 020
ER -