Influence of dislocations on photoluminescence of InGaN∕GaN multiple quantum wells

Abstract

The influence of dislocations on photoluminescence (PL) of InGaN∕GaN multiple quantum wells (MQWs) is investigated by triple-axis x-ray diffraction (TAXRD), transmission electron microscopy (TEM), and PL spectra. The ω scan of every satellite peak by TAXRD is adopted to evaluate the mean screw and edge dislocation densities in MQWs. The results show that dislocations can lead to a reduction of the PL-integrated intensity of InGaN∕GaN MQWs under certain conditions, with edge dislocations playing a decisive role. Additionally, the dislocations can broaden the PL peak, but the effect becomes evident only under the condition when the interface roughness is relatively low.