Optical properties of doped InGaN/GaN multiquantum-well structures

A systematic investigation of the photoluminescence spectra from InGaN/GaN multiquantum-well structures with different levels of Si doping in the quantum well has been carried out, in order to study the screening of the strain induced piezoelectric field and potential fluctuations. It is found that the emission energy strongly depends on the carrier concentration, originating from the doping or photogeneration. The observed strong shift with Si doping can only partly be explained by the screening of the piezoelectric field. The main shift is suggested to be related to the screening of the localization potentials.