Novel thin-GaN LED structure adopted micro abraded surface to compare with conventional vertical LEDs in ultraviolet light

Yen Chih Chiang; Chien Chung Lin; Hao Chung Kuo

doi:10.1186/s11671-015-0885-4

Novel thin-GaN LED structure adopted micro abraded surface to compare with conventional vertical LEDs in ultraviolet light

Nanoscale Res Lett. 2015 Apr 15:10:182. doi: 10.1186/s11671-015-0885-4. eCollection 2015.

Authors

Yen Chih Chiang¹, Chien Chung Lin², Hao Chung Kuo³

Affiliations

¹ Institute of Lighting and Energy Photonics, National Chiao Tung University, No.301, Gaofa 3rd Rd., Guiren Dist., Tainan City, 71150 Taiwan.
² Institute of Photonic System, National Chiao Tung University, No.301, Gaofa 3rd Rd., Guiren Dist., Tainan City, 71150 Taiwan.
³ Department of Photonics and Institute of Electro-Optical Engineering, National Chiao Tung University, 1001 University Road, Hsinchu, 300 Taiwan.

Abstract

In this study, novel thin-GaN-based ultraviolet light-emitting diodes (NTG-LEDs) were fabricated using wafer bonding, laser lift-off, dry etching, textured surface, and interconnection techniques. Placing PN electrodes on the same side minimized the absorption caused by electrodes in conventional vertical injection light-emitting diodes (V-LEDs) and the current spreading was improved. The light output power (700 mA) of the NTG-LEDs was enhanced by 18.3% compared with that of the V-LEDs, and the external quantum efficiency (EQE) of the NTG-LEDs was also relatively enhanced by 20.0% compared with that of a reference device. When the current operations were 1,500 mA, the enhancements of the light output power and EQE were 27.4% and 27.2%, respectively. Additionally, the efficiency droop was improved by more than 15% at the same current level.

Keywords: Gallium nitride; Light-emitting diode; Textured surface; Ultraviolet; Vertical injection.