[19a-E202-1~10] 15.4 III-V-group nitride crystals

[19a-E202-5] Improvement of EQE in AlGaN deep-UV LED fabricating highly-reflective PhC on p-GaN contact layer

〇Yukio Kashima^1,3, Yasuhiro Watanabe², Tomohiko Shibata², Noritoshi Maeda¹, Eriko Matsuura^1,3, Takeshi Iwai⁴, Mitsunori Kokubo⁵, Takaharu Tashiro⁵, Kanji Furuta⁶, Ryuichiro Kamimura⁶, Yamato Osada⁶, Hideki Takagi⁷, Yuichi Kurashima⁷, Yasushi Iwaisako⁸, Tsugumi Nagano⁹, Hideki Hirayama¹ (1.RIKEN, 2.DOWA Electronics, 3.Marubun, 4.Tokyo Ohka Kogyo, 5.Toshiba machine, 6.ULVAC, 7.AIST, 8.Nippon Tungsten, 9.Dai Nippon Printing)

Keywords:Deep-UV LED, Highly-reflective photonic crystal, p-GaN contact layer

Deep-UV LED sample was grown on 2 inch (0001) sapphire substrate, then highly-reflective photonic crystal(HR-PhC) was fabricated with low-damage on the surface of p-GaN contact layer by using a nanoimprint and ICP dry-etching process. The periodicity, diameter, and depth of air-hole PhC were 278nm, 190nm, and 135nm, respectively. External quantum efficiency in 274nm wavelength was improved from 2.3% to 3.7% with an enhacement factor of 1.6 because deep-UV light absorption on p-GaN contact layer was inhibited.