用Ξ形四能级模型研究非对称耦合量子阱非定域激子复合发光

基于Ξ形四能级模型运用密度矩阵方程研究了非对称量子阱中非定域激子复合发光特性.理论结果表明：非定域激子复合发光具有双峰特征，两峰相对于中心跃迁频率的红移和蓝移量与电子和空穴的振荡频率密切相关.与单量子阱相比，这种频率移动对外加电场相当敏感，即当外加反向电场作小的变化时，两峰有较大的移动，表现强量子限域斯塔克效应.这意味着利用非对称量子阱在新一代高速调制器和光开关中具有潜在的应用价值. 关键词： 非对称耦合量子阱 共振隧穿 非定域激子 量子限域斯塔克效应

Study of luminescence due to delocalized exciton recombination in asymmetric-coupled quantum well structure based on Ξ-type configuration

The luminescence properties due to the delocalized exciton recombination in the asymmetric-coupled quantum well (ACQW) structure have been studied based on Ξ-type configuration.We show that the luminescence has mainly two emission peaks:one peak corresponds to the red shift relative to the central transition frequency and the other to the blue shift.Compared with the single quantum well,this quantum-confined Stark shift is very sensitive to electric field.This means that the coupling between two wells for an ACQW structure leads to the enhancement of the quantum-confined Stark effect.From this optical property of ACQW,novel ultrafast optical modulation devices and optical switch fabricated with ACQW structure can be expected in the future optical communication system.