Unique temperature dependence of deep ultraviolet emission intensity for diamond light emitting diodes

作者：Kuwabara Daisuke^*; Makino Toshiharu; Takeuchi Daisuke; Kato Hiromitsu; Ogura Masahiko; Okushi Hideyo; Yamasaki Satoshi

来源：Japanese Journal of Applied Physics, 2014, 53(5): 05FP02.

DOI：10.7567/JJAP.53.05FP02

We have observed the temperature T (25-200 degrees C) dependence of the electrical and optical properties of diamond deep-ultraviolet (DUV) light emitting diodes (LEDs). The current-voltage characteristics showed a rectification ratio of 10(8) at +/- 20 V throughout the T range. In this LED, a strong DUV (235 nm) emission intensity due to free exciton radiative recombination was observed. At a constant injection current of 300 mA, the DUV emission intensity became four times larger at 200 degrees C than at 20 degrees C, that is, the external quantum efficiency of the diamond DUV-LED increases as T increases. This result is the converse of the T dependence trend of commercially available LEDs. A study of the T dependence of light extraction efficiency showed that this unique behavior is mainly due to the T dependence of the internal quantum efficiency of the diamond LED.

• 出版日期2014-5