Photoluminescence and photoluminescence excitation spectra of In0.2Ga0.8N-GaN quantum wells: Comparison between experimental and theoretical studies

InGaN-GaN represents an important heterostructure with applications in elec tronics and optoelectronics. It also offers a system where we can study the effects of interface roughness, alloy clustering, and the piezoelectric ef fect. In this paper, we examine how these factors influence the photolumine scence and excitation photoluminescence in InGaN-GaN quantum wells. We exam ine the Stokes shift as a function of the excitation level and doping and r elate the values to the piezoelectric effect and disorder in the system. De tailed comparisons are made with experimental results.