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Hou Y, Zhao D, Chen P, Liang F, Liu Z, Yang J. Stepped upper waveguide layer for higher hole injection efficiency in GaN-based laser diodes. OPTICS EXPRESS 2021; 29:33992-34001. [PMID: 34809198 DOI: 10.1364/oe.435062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 09/25/2021] [Indexed: 06/13/2023]
Abstract
We propose a stepped upper waveguide layer (UWG) to improve the hole injection efficiency of GaN-based laser diodes (LDs), and investigate its effect on the performance of LDs from experiments and theoretical calculations. The experimental characterization of the LD with stepped UWG presents a decrease of 16.6% for the threshold current as well as an increase of 41.2% for the slope efficiency compared to the LD with conventional GaN UWG. Meanwhile, strong localized effects are found in the quantum wells of LD with stepped UWG and a large blue-shift in the electroluminescence (EL) spectra below the threshold by analyzing the differential efficiency and the EL spectra. The large blue shift implies a stronger polarization field in the LDs, which may affect the injection of holes. Additionally, the simulation results demonstrate that the LD with stepped UWG achieves higher hole injection efficiency by modulating the valence band, and the hole current density injected into the quantum wells reaches 6067 A/cm2.
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Liang F, Zhao D, Jiang D, Liu Z, Zhu J, Chen P, Yang J, Liu S, Xing Y, Zhang L. Role of Si and C Impurities in Yellow and Blue Luminescence of Unintentionally and Si-Doped GaN. NANOMATERIALS 2018; 8:nano8121026. [PMID: 30544659 PMCID: PMC6316107 DOI: 10.3390/nano8121026] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 12/01/2018] [Accepted: 12/07/2018] [Indexed: 12/05/2022]
Abstract
Both yellow luminescence (YL) and blue luminescence (BL) bands of GaN films have been investigated for decades, but few works report the relationship between them. In this study, two sets of GaN samples grown via metalorganic chemical vapor deposition (MOCVD) were investigated. A close relationship was found between the YL and BL bands for unintentionally doped GaN and Si-doped GaN samples, both of which were grown without intentional acceptor doping. It was found that the intensity ratio of blue luminescence to yellow luminescence (IBL/IYL) decreases sharply with the increase in carbon impurity concentration, even though both IBL and IYL increase obviously. It was also found that IBL/IYL decreases sharply with the increase in Si doping concentration. It is suggested that the C and Si impurities play important role in linkage and competition of the blue and yellow luminescence.
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Affiliation(s)
- Feng Liang
- State Key Laboratory of Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.
| | - Degang Zhao
- State Key Laboratory of Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Desheng Jiang
- State Key Laboratory of Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.
| | - Zongshun Liu
- State Key Laboratory of Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Jianjun Zhu
- State Key Laboratory of Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.
| | - Ping Chen
- State Key Laboratory of Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.
| | - Jing Yang
- State Key Laboratory of Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.
| | - Shuangtao Liu
- State Key Laboratory of Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.
| | - Yao Xing
- State Key Laboratory of Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.
| | - Liqun Zhang
- Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou 215123, China.
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Zhu Y, Lu T, Zhou X, Zhao G, Dong H, Jia Z, Liu X, Xu B. Effect of hydrogen treatment temperature on the properties of InGaN/GaN multiple quantum wells. NANOSCALE RESEARCH LETTERS 2017; 12:321. [PMID: 28472870 PMCID: PMC5413467 DOI: 10.1186/s11671-017-2109-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 04/24/2017] [Indexed: 06/07/2023]
Abstract
InGaN/GaN multiple quantum wells (MQWs) were grown with hydrogen treatment at well/barrier upper interface under different temperatures. Hydrogen treatment temperature greatly affects the characteristics of MQWs. Hydrogen treatment conducted at 850 °C improves surface and interface qualities of MQWs, as well as significantly enhances room temperature photoluminescence (PL) intensity. In contrast, the sample with hydrogen treatment at 730 °C shows no improvement, as compared with the reference sample without hydrogen treatment. On the basis of temperature-dependent PL characteristics analysis, it is concluded that hydrogen treatment at 850 °C is more effective in reducing defect-related non-radiative recombination centers in MQWs region, yet has little impact on carrier localization. Hence, hydrogen treatment temperature is crucial to improving the quality of InGaN/GaN MQWs.
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Affiliation(s)
- Yadan Zhu
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, 030024, Taiyuan, China
- Research Center of Advanced Materials Science and Technology, Taiyuan University of Technology, 030024, Taiyuan, China
| | - Taiping Lu
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, 030024, Taiyuan, China.
- Research Center of Advanced Materials Science and Technology, Taiyuan University of Technology, 030024, Taiyuan, China.
| | - Xiaorun Zhou
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, 030024, Taiyuan, China
- Research Center of Advanced Materials Science and Technology, Taiyuan University of Technology, 030024, Taiyuan, China
| | - Guangzhou Zhao
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, 030024, Taiyuan, China
- Research Center of Advanced Materials Science and Technology, Taiyuan University of Technology, 030024, Taiyuan, China
| | - Hailiang Dong
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, 030024, Taiyuan, China
- Research Center of Advanced Materials Science and Technology, Taiyuan University of Technology, 030024, Taiyuan, China
| | - Zhigang Jia
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, 030024, Taiyuan, China
- Research Center of Advanced Materials Science and Technology, Taiyuan University of Technology, 030024, Taiyuan, China
| | - Xuguang Liu
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, 030024, Taiyuan, China
- College of Chemistry and Chemical Engineering, Taiyuan University of Technology, 030024, Taiyuan, China
| | - Bingshe Xu
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, 030024, Taiyuan, China.
- Research Center of Advanced Materials Science and Technology, Taiyuan University of Technology, 030024, Taiyuan, China.
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