GaN‐Based Light‐Emitting Diodes and Laser Diodes, and Their Recent Progress

It is recognized that GaN-based semiconductor is the most excellent material for short wavelength emitting devices. In this paper, we review the development of InGaN light emitting diodes (LEDs) and laser diodes (LDs). Additionally, purely-blue LDs are demonstrated, and the emission-wavelength dependence of the threshold current density is studied.