Polarization is a crucial issue for electrical and optical characteristics of the UV AlGaInN light-emitting diodes. The effect of spontaneous and piezoelectric polarization on optical characteristics of the UV AlGaInN light-emitting diodes is investigated numerically. The simulation results indicate that the polarization-related effect for the UV AlGaInN light-emitting diodes is dominated by the piezoelectric polarization. When the UV AlGaInN light-emitting diodes are without piezoelectric polarization, the optical performance is enhanced effectively due to improved overlap of electron and hole wavefunctions, reduced electron leakage current, and increased density of holes in the active region.
