Design strategies for mitigating the influence of polarization effects on GaN-based multiple quantum well light-emitting diodes

The optoelectronic properties of GaN-based multiple quantum well (MQW) light-emitting diodes (LEDs) are investigated using a detailed theoretical model, in which the effects of strain, well coupling, valence band mixing, and polarization effects are fully considered. By solving the conduction and valence band effective mass equations together with Poisson’s equation self-consistently, the influence of various major design parameters, such as the well width, the barrier components, and the barrier thickness, on the electronic and optical properties of GaN-based MQW LEDs is studied. Numerical results show that the emission spectra of the LEDs are very sensitive to the above design parameters due to the polarization effect that is unique for GaN-based devices. Further analysis and simulations reveal that this sensitivity can be obviously suppressed by choosing InGaN as the barrier material.