Ultraviolet laser diodes on sapphire and AlN substrates
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 III-nitride laser heterostructures were grown on (0001) AlN and c-plane sapphire substrates by metalorganic vapor phase epitaxy (MOVPE). Lasing was observed for optically pumped AlGaInN 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 AlN with threshold densities as low as 175 kW/cm2 for lasers emitting near 330 nm.
Kneissl, M. A.; Yang, Z. H.; Teepe, M. R.; Johnson, N. M. Ultraviolet laser diodes on sapphire and AlN substrates. Novel In-Plane Semiconductor Lasers VII at Photonics West; 2009 January 26; San Jose, CA. Bellingham, WA: SPIE; 2009; 7230: 72300E.