GaN-BASED LIGHT-EMITTING DIODES FOR VERTICAL CURRENT INJECTION BY LASER LIFT-OFF AND WAFER BONDING TECHNIQUES

摘要

This work reports a p-side-down GaN/mirror/Si light-emitting diode (LED) for vertical current injection fabricated by laser lift-off and wafer bonding techniques. The large area (1 mmx1 mm) GaN/mirror/Si LED with a platinum mirror presents a luminance intensity of 1456 mcd (@350mA) with a forward voltage of 3.96 V. The luminance intensity is two times in magnitude as compared with that of the original GaN/sapphire LED (456mcd, 4.2V @ 350mA). When the driving current increased to 1A, the luminance intensity of GaN/mirror/Si LED achieved 2876 mcd, which was 2.8 times in magnitude as compared with that of the original planar GaN/sapphire LED (@1019mcd). These results indicate that the wafer bonding and laser lift-off techniques do not adversely affect the current-voltage characteristics of the LEDs. Furthermore, under high current injection, the GaN/mirror/Si LED presents the better performance due to the Si heat sink.