Green Vertical-Cavity Surface-Emitting Lasers Based on InGaN Quantum Dots and Short Cavity

Tao Yang; Yan-Hui Chen; Ya-Chao Wang; Wei Ou; Lei-Ying Ying; Yang Mei; Ai-Qin Tian; Jian-Ping Liu; Hao-Chung Guo; Bao-Ping Zhang

doi:10.1007/s40820-023-01189-0

Green Vertical-Cavity Surface-Emitting Lasers Based on InGaN Quantum Dots and Short Cavity

Nanomicro Lett. 2023 Oct 9;15(1):223. doi: 10.1007/s40820-023-01189-0.

Authors

Tao Yang¹, Yan-Hui Chen¹, Ya-Chao Wang¹, Wei Ou¹, Lei-Ying Ying¹, Yang Mei², Ai-Qin Tian³, Jian-Ping Liu⁴, Hao-Chung Guo^{5

6}, Bao-Ping Zhang⁷

Affiliations

¹ Laboratory of Micro/Nano-Optoelectronics, School of Electronic Science and Engineering, Xiamen University, Xiamen, 361005, Fujian, People's Republic of China.
² Laboratory of Micro/Nano-Optoelectronics, School of Electronic Science and Engineering, Xiamen University, Xiamen, 361005, Fujian, People's Republic of China. meiyang@xmu.edu.cn.
³ Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, 215123, Jiangsu, People's Republic of China.
⁴ Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, 215123, Jiangsu, People's Republic of China. jpliu2010@sinano.ac.cn.
⁵ Department of Photonics, National Yang Ming Chiao Tung University, Hsinchu, 30010, Taiwan, People's Republic of China.
⁶ Semiconductor Research Center, Honhai Research Institute, New Taipei, 220236, Taiwan, People's Republic of China.
⁷ Laboratory of Micro/Nano-Optoelectronics, School of Electronic Science and Engineering, Xiamen University, Xiamen, 361005, Fujian, People's Republic of China. bzhang@xmu.edu.cn.

Abstract

Room temperature low threshold lasing of green GaN-based vertical cavity surface emitting laser (VCSEL) was demonstrated under continuous wave (CW) operation. By using self-formed InGaN quantum dots (QDs) as the active region, the VCSEL emitting at 524.0 nm has a threshold current density of 51.97 A cm^-2, the lowest ever reported. The QD epitaxial wafer featured with a high IQE of 69.94% and the δ-function-like density of states plays an important role in achieving low threshold current. Besides, a short cavity of the device (~ 4.0 λ) is vital to enhance the spontaneous emission coupling factor to 0.094, increase the gain coefficient factor, and decrease the optical loss. To improve heat dissipation, AlN layer was used as the current confinement layer and electroplated copper plate was used to replace metal bonding. The results provide important guidance to achieving high performance GaN-based VCSELs.

Keywords: GaN; Green vertical cavity surface emitting laser; InGaN quantum dots; Low threshold.