Influence of GaN Material Characteristics on Device Performance for Blue and Ultraviolet Light-Emitting Diodes
Authors: Merfeld, D.W.; Cao, X.A.; Leboeuf, S.F.; Arthur, S.D.; Kretchmer, J.W.; Develyn, M.P.
Source: Journal of Electronic Materials, Volume 33, Number 11, November 2004 , pp. 1401-1405(5)
Abstract:An analysis of blue and near-ultraviolet (UV) light-emitting diodes (LEDs) and material structures explores the dependence of device performance on material properties as measured by various analytical techniques. The method used for reducing dislocations in the epitaxial III-N films that is explored here is homoepitaxial growth on commercial hydride vapor-phase epitaxy (HVPE) GaN substrates. Blue and UV LED devices are demonstrated to offer superior performance when grown on GaN substrates as compared to the more conventional sapphire substrate. In particular, the optical analysis of the nearUV LEDs on GaN versus ones on sapphire show substantially higher light output over the entire current-injection regime and twice the internal quantum efficiency at low forward current. As the wavelength is further decreased to the deep-UV, the performance improvement of the homoepitaxially grown structure as compared to that grown on sapphire is enhanced.
Document Type: Regular paper
Publication date: 2004-11-01