High Brightness GaN Vertical Light-Emitting Diodes on Metal Alloy for General Lighting Application

In this paper, we show the many advantages of the GaN-based vertical light-emitting diodes (VLEDs) on metal alloy over conventional LEDs in terms of: better current spreading, vertical current path for low operation voltage, better light extraction, flexible chip size scaling, higher driving current density, faster heat dissipation, and good reliability. The GaN VLED on metal alloy exhibits very good current-voltage behavior with low operated voltage and low serial dynamic resistance. The low operation junction temperature of GaN VLED on metal alloy demonstrates excellent heat dissipation capabilities. Chip size scaling without efficiency loss shows a unique property of GaN VLED on metal alloy. The GaN VLED on metal alloy also enables top surface engineering for efficient light extraction to further light output. A high-power white LED having efficiency of 120 lumen/W was achieved through a combination of reflector, surface engineering, and optimization of the n-GaN layer thickness. Coupled with good reliability and mass production ability, the GaN VLED on metal alloy is very suitable for general lighting application.