Ultraviolet laser diodes on sapphire and AlN substrates

摘要

The performance characteristics of InAlGaN multiple quantum well (MQW) lasers grown on sapphire and low defect density bulk AlN substrates has been compared. The group Ill-nitride laser heterostructures were grown on (0001) A1N and c-plane sapphire substrates by metalorganic vapor phase epitaxy (MOVPE). Lasing was observed for optically pumped AlGalnN heterostructures in the wavelength range between 333 nm and 310 nm. A comparison of laser thresholds shows reduced threshold power densities for lasers grown on bulk A1N with threshold densities as low as 175 kW/cm~2 for lasers emitting near 330 nm.