Investigation of Photoluminescence and Photoreflectance in MBE-Grown GaInNAs/GaAs QWs
GaInNAs/GaAs量子阱的光致发光谱和光调制反射谱

Photoluminescence (PL) and photoreflectance (PR) spectra of GaInNAs/GaAs multiple quantum wells (MQWs) grown on GaAs substrate by MBE are measured over a range of temperature and excitation power density.The energy position of dominant PL peak shows an anomalous S shape temperature dependence instead of Varshni relation.By the careful inspection,especially for the PL under lower excitation power density,two near band edge peaks are well identified.They are assigned to carriers localized by nitrogen induced bound states and interband excitonic recombinations respectively.It is suggested that the temperature-induced switch of such two luminescence peaks in relative intensity causes a significant mechanism responsible for the observed S shape shift in GaInNAs.A quantitative model based on the thermal excitation and depopulation of carriers is used to explain the temperature dependence of the PL peak related to N induced bound states.