Enhancement of light output power of GaN-based light-emitting diodes with photonic quasi-crystal patterned on p-GaN surface and n-side sidewall roughing
1 Department of Photonic Engineering, Yuan Ze University, 135 Yuan-Tung Rd, Jung-Li, Tao-Yuan country 32003, Taiwan
2 Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 701, Taiwan
Nanoscale Research Letters 2013, 8:244 doi:10.1186/1556-276X-8-244Published: 17 May 2013
In this paper, GaN-based light-emitting diodes (LEDs) with photonic quasi-crystal (PQC) structure on p-GaN surface and n-side roughing by nano-imprint lithography are fabricated and investigated. At an injection current of 20 mA, the LED with PQC structure on p-GaN surface and n-side roughing increased the light output power of the InGaN/GaN multiple quantum well LEDs by a factor of 1.42, and the wall-plug efficiency is 26% higher than the conventional GaN-based LED type. After 500-h life test (55°C/50 mA), it was found that the normalized output power of GaN-based LED with PQC structure on p-GaN surface and n-side roughing only decreased by 6%. These results offer promising potential to enhance the light output powers of commercial light-emitting devices using the technique of nano-imprint lithography.