• 文献标题:   Evidence of minority carrier injection efficiency >90% in an epitaxial graphene/SiC Schottky emitter bipolar junction phototransistor for ultraviolet detection
  • 文献类型:   Article
  • 作  者:   CHAVA VSN, OMAR SU, BROWN G, SHETU SS, ANDREWS J, SUDARSHAN TS, CHANDRASHEKHAR MVS
  • 作者关键词:  
  • 出版物名称:   APPLIED PHYSICS LETTERS
  • ISSN:   0003-6951 EI 1077-3118
  • 通讯作者地址:   Univ S Carolina
  • 被引频次:   12
  • DOI:   10.1063/1.4940385
  • 出版年:   2016

▎ 摘  要

In this letter, we report the UV detection characteristics of an epitaxial graphene (EG)/SiC based Schottky emitter bipolar phototransistor (SEPT) with EG on top as the transparent Schottky emitter layer. Under 0.43 mu W UV illumination, the device showed a maximum common emitter current gain of 113, when operated in the Schottky emitter mode. We argue that avalanche gain and photoconductive gain can be excluded, indicating minority carrier injection efficiency, gamma, as high as 99% at the EG/p-SiC Schottky junction. This high gamma is attributed to the large, highly asymmetric barrier, which EG forms with the p-SiC. The maximum responsivity of the UV phototransistor is estimated to be 7.1 A/W. The observed decrease in gain with increase in UV power is attributed to recombination in the base region, which reduces the minority carrier lifetime. (C) 2016 AIP Publishing LLC.