Theoretical Study of Optical Transition Matrix Elements in InGaN/GaN SQW Subject to Indium Surface Segregation

We investigate the dependence of dipole matrix elements for InGaN/GaN single quantum well structures on the indium surface segregation (ISS). Obtained results show that the influence of the surface segregation on the dipole matrix element is not equal for all optical transition. This effect results from the joint action of the piezoelectric polarization and ISS that change selection rules. In addition, surface segregation at each interface of the quantum well has different impact on optical characteristics depending on the direction of the piezoelectric polarization. The effect of the surface segregation has been estimated applying the global sensitivity analysis in the frame of six-band approximation for the valence band and parabolic approximation for the conduction band.