Impact of low-temperature buffer layers on nitride-based optoelectronics

A historical overview and recent trends in the research and development of nitride-based light emitters are presented. The growth of GaN using a low-temperature-deposited buffer layer conductivity control, and the use of GaInN alloys, by which nonradiative recombination centers in nitrides are screened, have been employed to fabricate high-efficiency blue and green light-emitting diodes. Today, luminous flux efficiency of up to 50 lm/W at a specific wavelength is available. Electrical pumping has realized commercial laser diodes in the violet and blue regions. Several milestones in the realization of these achievements are reviewed. Future prospects of the nitride-based light emitters are also discussed.