GaN基蓝光VCSEL的制备及光学特性

摘要

利用金属有机物气相沉积技术(MOCVD)在(0001)蓝宝石衬底上生长了 GaN 基垂直腔面发射激光器( VCSEL)的多量子阱腔层结构。 X射线衍射测量显示该多量子阱具有良好周期结构和平整界面。运用键合及激光剥离技术将该外延片制作成 VCSEL,顶部和底部反射镜为极高反射率的介质膜分布布拉格反射镜(DBR)。在室温、紫外脉冲激光的泵浦条件下,观察到了VCSEL明显的激射现象,峰值波长位于447.7 nm,半高宽为0.11 nm,自发辐射因子约为6.0×10-2,阈值能量密度约为8.8 mJ/cm2。在大幅度降低制作难度的情况下,得到目前国际最好结果同样数量级的激射阈值。降低器件制作难度有利于制备的重复性,有利于器件的产品化。%GaN-based multiple quantum wells (MQWs) were epitaxially grown on (0001)-oriented sapphire substrate by metal organic chemical vapor deposition ( MOCVD) technique. X-ray diffrac-tion measurements indicated that the MQWs had good periodic structure and smooth interface. By employing bonding and laser lift-off techniques, the MQW structure was sandwiched between two high reflectivity dielectric distributed Bragg reflectors ( DBRs ) , forming a vertical-cavity surface-emitting laser ( VCSEL) . Under optical pumping, the VCSEL achieved laser action at room temper-ature with a threshold pumping energy density of about 8. 8 mJ/cm2 . The laser emitted a blue light at 447. 7 nm with a narrow linewidth of 0. 11 nm, and had a high spontaneous emission factor of about 6 . 0í10 -2 .