Lingrong Jiang 1,2,3Jianping Liu 1,2,3,*Lei Hu 1,2,3Liqun Zhang 1,3[ ... ]Hui Yang 1,2,3
Author Affiliations
Abstract
1 Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou 215123, China
2 School of Nano-tech and Nano-bionics, University of Science and Technology of China, Hefei 230026, China
3 Key Laboratory of Nanodevices and Applications, Chinese Academy of Sciences, Suzhou 215123, China
4 Nano Science and Technology Institute, University of Science and Technology of China, Hefei 230026, China
Absorption induced by activated magnesium (Mg) in a p-type layer contributes considerable optical internal loss in GaN-based laser diodes (LDs). An LD structure with a distributed polarization doping (DPD) p-cladding layer (CL) without intentional Mg doping was designed and fabricated. The influence of the anti-waveguide structure on optical confinement was studied by optical simulation. The threshold current density, slope efficiency of LDs with DPD p-CL, and Mg-doped CL, respectively, were compared. It was found that LDs with DPD p-CL showed lower threshold current density but reduced slope efficiency, which were caused by decreasing internal loss and hole injection, respectively.
polarization doping internal loss GaN laser diode Chinese Optics Letters
2021, 19(12): 121404
1 中国科学技术大学纳米技术与纳米仿生学院,合肥 230026
2 中国科学院苏州纳米技术与纳米仿生研究所,纳米器件与应用重点实验室,苏州 215123
氮化镓(GaN)基蓝光和绿光激光器在投影显示、激光加工、激光照明、存储等领域具有重要的应用前景与广泛的市场需求。本文着重介绍了GaN基蓝光和绿光边发射激光器的技术难点和相应的解决方案。在GaN基蓝光与绿光激光器中,就制备高质量InGaN/GaN多量子阱、减少内部光学损耗、增加空穴注入效率等方面分别介绍了一些结构与工艺方面的优化方法。简要介绍了垂直腔面发射激光器(VCSEL)、分布式反馈激光器(DFB)的研究现状。
半导体激光器 氮化镓 热退化 In偏析 内部光学损耗 载流子注入效率 semiconductor laser diode GaN thermal degradation In segregation internal optical loss carrier injection
Author Affiliations
Abstract
1 Key Laboratory of Nanodevices and Applications, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (CAS), Suzhou 215123, China
2 School of Nano-Tech and Nano-Bionics, University of Science and Technology of China, Hefei 230026, China
Green laser diodes (LDs) still perform worst among the visible and near-infrared spectrum range, which is called the “green gap.” Poor performance of green LDs is mainly related to the p-type AlGaN cladding layer, which on one hand imposes large thermal budget on InGaN quantum wells (QWs) during epitaxial growth, and on the other hand has poor electrical property especially when low growth temperature has to be used. We demonstrate in this work that a hybrid LD structure with an indium tin oxide (ITO) p-cladding layer can achieve threshold current density as low as , which is only one third of that of the conventional LD structure. The improvement is attributed to two benefits that are enabled by the ITO cladding layer. One is the reduced thermal budget imposed on QWs by reducing p-AlGaN layer thickness, and the other is the increasing hole concentration since a low Al content p-AlGaN cladding layer can be used in hybrid LD structures. Moreover, the slope efficiency is increased by 25% and the operation voltage is reduced by 0.6 V for hybrid green LDs. As a result, a 400 mW high-power green LD has been obtained. These results indicate that a hybrid LD structure can pave the way toward high-performance green LDs.
Photonics Research
2020, 8(3): 03000279