Fabrication and Improved Performance of GaN LEDs With Finger-Type Structure

This paper demonstrates that vertical gallium nitride (GaN) light-emitting diodes (LEDs) with a finger-type current spreading structure (referred as F-LEDs), and wing-type vertical LEDs with embedded contact (W-LEDs) exhibit improved performance in output power and current spreading compared with conventional LED (C-LED). Although W-LED and F-LED designs allow improved light shading and current crowding, the extra finger-type structure promotes a better current spread, resulting in performance superior to that of C-LEDs and W-LEDs. Under an injection current of 350 mA, 329.39 mW of output power is obtained in F-LEDs corresponding to a performance enhancement of 39.3% and 20.3% compared with C-LEDs and W-LEDs, respectively. When the driving current was increased to 700 mA, the finger-type structure increased output power and efficiency droop reduction benefits were clearly observed. The F-LEDs exhibited 24% enhanced power and 23% improved droop in comparison with W-LEDs.