Equilibrium between spontaneous polarization, piezoelectric polarization and crystal defects for blue LEDs on sapphire substrate

High power InGaN-based blue LEDs have been commercialized despite the presence of a high dislocation density in the heteroepitaxial structures. Traditional trial-and-error techniques are very inefficient for improving the process of MOVCD. We analyze the relationship between spontaneous, piezoelectric polarization and crystal defaults by adjusting screening values. The simulation results shows to improve characteristics of blue LEDs on sapphire substrate, interfacial charges for piezoelectric and polarization should get equilibrium with crystal defects. And it may be the real lighting mechanism for InGaN-based blue LEDs with high dislocation density.