带间级联激光器电子注入区优化研究(特邀)  

Optimization of Electron Injectors for Interband Cascade Lasers(Invited)

作　　者：宁超 孙瑞轩 于天[1,2] 刘舒曼 张锦川[1,2] 卓宁 王利军[1,2] 刘俊岐 翟慎强[1,2] 李远 刘峰奇[1,2,3] NING Chao;SUN Ruixuan;YU Tian;LIU Shuman;ZHANG Jinchuan;ZHUO Ning;WANG Lijun;LIU Junqi;ZHAI Shenqiang;LI Yuan;LIU Fengqi(Key Laboratory of Semiconductor Materials Science,Institute of Semiconductors,Chinese Academy of Sciences,Beijing 100083,China;Center of Materials Science and Opto-electronic Engineering,University of Chinese Academy of Sciences,Beijing 100049,China;Beijing Academy of Quantum Information Sciences,Beijing 100193,China)

机构地区：[1]中国科学院半导体研究所半导体材料科学重点实验室,北京100083 [2]中国科学院大学材料与光电研究中心,北京100049 [3]北京量子信息科学研究院,北京100193

出　　处：《光子学报》2022年第2期90-96,共7页Acta Photonica Sinica

基　　金：国家重点研究发展计划(No.2018YFB2200500);国家自然科学基金(Nos.61790583,61774150,61774151);中科院先导专项(No.XDB43000000)。

摘　　要：带间级联激光器有源区内部的物理机制复杂,尚未得到充分研究。优化了电子注入区结构,通过减小InAs/AlSb啁啾超晶格中InAs量子阱的厚度促进电子向光增益区的注入,在较低的电子注入区掺杂浓度下满足了光增益区电子数和空穴数基本相等的注入平衡条件,降低了有源区中自由载流子吸收和杂质散射造成的光损耗。采用该有源区结构的带间级联激光器实现了较好的室温激射性能,腔长4 mm、脊宽20μm且腔面未镀膜器件的阈值电流为200 mA,单腔面出光功率为55 mW。通过分析2~5 mm不同腔长器件的电压-电流-光功率性能,得到器件的波导损耗仅为3 cm^(-1),有源区载流子寿命为0.7 ns。The Interband Cascade Laser(ICL)is a mid-infrared laser source with a low threshold current density,which has been used widely in hydrocarbon detection and other gases.One active region stage of an ICL consists of an In As/Ga In Sb/In As W Quantum Well(QW)emitter,Ga Sb/Al Sb QW hole injector and In As/Al Sb chirped superlattice electron injector.In contrast to the intersubband electron transition and transportation in quantum cascade lasers,interband transitions and carrier transportation from valance band to conduction band through a semimetallic interface are involved in an ICL.As the electron injector is longer than the hole injector,most ionized electrons are located in the lower subbands away from the emitter,and the efficiency of electron injection into the emitter is lower than that of holes,resulting in a large number of excess holes in the emitter.The existence of these holes causes the non-radiative Auger recombination and deteriorates the laser performance.Heavy doping,on the other size,may cause large free-carrier absorption loss and impurity scattering loss in the active region.In this work,the thickness of the electron injector was thinned to improve the electron injection efficiency by increasing the subband energy level of the electron injector.The doping concentration required for the carriers’rebalance was reduced,which led to a low internal loss.Two ICL wafers were grown in a molecular beam epitaxy system on Te-doped Ga Sb substrates.achieved excellent room temperature lasing performance.One stage of the active region of sample S1 is as follows:2.5 nm Al Sb/1.8 nm In As/3.0 nm Ga0.7In0.3Sb/1.5 nm In As/1.0 nm Al Sb/3.0 nm Ga Sb/1.0 nm Al Sb/4.5 nm Ga Sb/2.0 nm Al Sb/3.4 nm In As/1.2 nm Al Sb/3.0 nm In As/1.2 nm Al Sb/2.6 nm In As/1.2 nm Al Sb/2.1 nm In As/1.2 nm Al Sb/1.8 nm In As/1.2 nm Al Sb/1.8 nm In As,where the underlined In As QWs were doped with Si to 2×1018cm3.For comparison,sample S2 with a thick electron injector of 4.2 nm In As/1.2 nm Al Sb/3.2 nm In As/1.2 nm Al Sb/2.5 nm In As/1

关 键 词：半导体激光器 中红外 分子束外延 带间级联激光器 量子阱 锑化物 

分 类 号：TN248.4[电子电信—物理电子学]