InGaN/GaN量子阱垒层和阱层厚度对GaN基激光器性能的影响及机理  

Barrier and well thickness designing of InGaN/GaN multiple quantum well for better performances of GaN based laser diode

作　　者：周梅[1] 赵德刚[2] 

机构地区：[1]中国农业大学理学院应用物理系,北京100083 [2]中国科学院半导体研究所,集成光电子学国家重点实验室,北京100083

出　　处：《物理学报》2016年第7期316-321,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:61474142)资助的课题~~

摘　　要：采用LASTIP软件研究了InGaN/GaN(In组分为15%)量子阱垒层和阱层厚度对GaN基蓝紫光激光器性能的影响及机理.模拟计算结果表明,当阱层太薄或太厚时,GaN基激光器的阈值电流增加、输出功率下降,最优的阱层厚度为4.0 nm左右;当阱层厚度太薄时,载流子很容易泄漏,而当阱层厚度太厚时,极化效应导致发光效率降低,研究还发现,与垒层厚度为7 nm相比,垒层厚度为15 nm时激光器的阈值电流更低、输出功率更高,因此适当地增加垒层厚度能显著抑制载流子泄漏,从而改善激光器性能.The effects of barrier and well thickness in In GaN/GaN（with in content of 15%） multiple quantum well（MQW） on the performances of Ga N based laser diode（LD） are investigated by using LASTIP software, and the relevant physical mechanisms are discussed. It is found that when the barrier-thickness in InGaN/GaN MQW is fixed to be 7 nm, for the well thickness values of 3.0, 3.5, 4.0, 4.5, and 5.0 nm, the threshold currents of LD are 76.31, 67.96, 57.60, 64.62, and 74.59 mA, and the output light powers of LD are 12.05, 15.64, 24.70, 18.21, and 11.35 mW under an injection current of 100 mA, respectively. It indicates that too thick or too thin well may lead to a higher threshold current and a lower output power of GaN based LD. A high performance device can be obtained by using an optimized well thickness of around 4.0 nm. It is found that the LD performance is degraded by using too thin well in the device structure mainly due to the high leakage current, while strong polarization will lead to the decrease of overlap integral and luminescence intensity if the well layer is too thick, and thus a poor performance is obtained. It is found that the LD performance can be improved obviously by appropriately increasing barrier thickness from 7 nm to 15 nm. When the barrier thickness in In GaN/GaN MQW is fixed at 15 nm and the well thickness values are 3.0, 3.5, 4.0, 4.5 and 5.0 nm, the threshold currents of LD are 59.54, 52.42, 52.17, 51.38, and 58.99 mA, and the output light powers of LD are 36.12, 39.69, 40.79,40.27, and 33.19 mW under an injection current of 100 mA, respectively, i.e., LD device parameters are improved. It suggests that the higher performances of GaN based laser diode can be realized by appropriately increasing the thickness of barrier when the thickness of well is optimized to be around 4 nm.

关 键 词：GAN基激光器 InGaN/GaN量子阱 垒层和阱层厚度 

分 类 号：TN248[电子电信—物理电子学] O471.1[理学—半导体物理]