High-efficiency InGaN-based LEDs grown on patterned sapphire substrates.

GaN films grown on PSS are investigated by XRD, CL, SEM and TEM. There are low threading dislocations (TDs) with larger fill factor, which results in better electrostatic discharge (ESD) yield of LEDs. The effect of growth rate on dislocations in GaN films grown on PSS is investigated by TEM. It is found that dislocations density decreases as the growth rates decrease. And the performance of InGaN-based LEDs on different PSS is analyzed. The performance of LEDs grown on different PSS is determined by slanted angle and fill factor simultaneously.