Investigation of the optical properties in InGaN/GaN quantum well structure

The paper investigates the optical properties of InGaN/GaN single quantum well and multiple quantum well structures. For the multiple quantum well structure, we investigated the thickness dependence of the optical properties. Based on these studies, this paper presents 1. for the single quantum well structure with 2.5 nm well thickness, there exists a strong piezoelectric field, which induces the quantum confined Stark effect; 2. for the ten period multiple quantum well structure, if the well thickness is 2.5 nm, there is no apparent piezoelectric field to be observed. If the well thickness is above 2.5 nm, the optical behavior can be explained by a model based on the formation of self-organized small In-rich regions, rather than by the piezoelectric field-induced quantum confined Stark effect.