Effect of p-GaN layer grown with H2 carrier gas on wall-plug efficiency of high-power LEDs. (June 2017)

• Record Type: Journal Article
• Authors: Lu, Kuan Fu; Lin, Tien Kun; Liou, Jian Kai; Yang, Chyi Da; Lee, Chong Yi; Tsai, Jeng Da
• Is Part Of: Solid-state electronics. Volume 132(2017)
• Page Start: 86
• Page End: 90
• Publication Date: 2017-06
• Subjects: Carrier gas -- p-GaN -- Wall-plug efficiency -- Current spreading; Semiconductors -- Periodicals; Semiconducteurs -- Périodiques; 621.38152
• DOI: 10.1016/j.sse.2017.03.012
• Languages: English
• ISSNs: 0038-1101

Abstract

Highlights: The p-H2 layer can effectively improve the WPE performance of GaN-based LEDs for high power application. GaN crystal growth in H2 ambient, better quality and smoother surface of the p-GaN can be obtained. The current spreading performance of the p-GaN layer using H2 alone as the carrier gas could be enhanced. Turn-on voltage and dynamic resistance at 500 mA could be reduced by 0.12 V and 0.13 Ω, respectively. The studied device also exhibits improvement in electrostatic discharge robustness. Abstract: The effect of employing different carrier gases (H2 only and 1:1 vol% N2 :H2 ) in the p-type GaN (p-GaN) layer on the wall-plug efficiency (WPE) of high-power light-emitting diodes (LEDs) is studied. Since GaN crystal could be a two-dimension (2-D) growth mode in H2 ambient, better quality and smoother surface of the p-GaN were obtained. The current spreading performance of the p-GaN layer using H2 alone as the carrier gas was enhanced, resulting in advanced light output power (LOP). In addition, turn-on voltage and dynamic resistance at 500 mA, which can strongly contribute to the WPE, were also reduced by 0.12 V and 0.13 Ω, respectively. The studied device with H2 as the carrier gas in the p-GaN layer (p-H2 layer) exhibits 9.5% and 12.4% improvements in LOP and WPE at 500 mA over the device (N2 /H2 = 1:1), as well as significantly better electrostatic discharge robustness. Therefore, the use of a p-H2 layer can effectively improve the performance of GaN-based LEDs for high power applications.