Yang Tao, Chen Yan-Hui, Wang Ya-Chao, Ou Wei, Ying Lei-Ying, Mei Yang, Tian Ai-Qin, Liu Jian-Ping, Guo Hao-Chung, Zhang Bao-Ping
Laboratory of Micro/Nano-Optoelectronics, School of Electronic Science and Engineering, Xiamen University, Xiamen, 361005, Fujian, People's Republic of China.
Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, 215123, Jiangsu, People's Republic of China.
Nanomicro Lett. 2023 Oct 9;15(1):223. doi: 10.1007/s40820-023-01189-0.
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, 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.
在连续波（CW）工作条件下，实现了基于绿色GaN的垂直腔面发射激光器（VCSEL）的室温低阈值激射。通过使用自形成的InGaN量子点（QD）作为有源区，发射波长为524.0 nm的VCSEL的阈值电流密度为51.97 A/cm²，这是迄今为止报道的最低值。具有69.94%的高内部量子效率（IQE）和类δ函数态密度的量子点外延片在实现低阈值电流方面起着重要作用。此外，该器件的短腔（约4.0λ）对于将自发发射耦合因子提高到0.094、增加增益系数因子和降低光损耗至关重要。为了改善散热，采用AlN层作为电流限制层，并使用电镀铜板代替金属键合。这些结果为实现高性能基于GaN的VCSEL提供了重要指导。
