• 文献标题:   Terahertz Photoconductivity in Bilayer Graphene Transistors: Evidence for Tunneling at Gate-Induced Junctions
  • 文献类型:   Article
  • 作  者:   MYLNIKOV DA, TITOVA EI, KASHCHENKO MA, SAFONOV IV, ZHUKOV SS, SEMKIN VA, NOVOSELOV KS, BANDURIN DA, SVINTSOV DA
  • 作者关键词:   bilayer graphene, photoconductivity, pn junction, photodetector, tunneling, transistor
  • 出版物名称:   NANO LETTERS
  • ISSN:   1530-6984 EI 1530-6992
  • 通讯作者地址:  
  • 被引频次:   3
  • DOI:   10.1021/acs.nanolett.2c04119 EA DEC 2022
  • 出版年:   2023

▎ 摘  要

Photoconductivity of novel materials is the key property of interest for design of photodetectors, optical modulators, and switches. Despite the photoconductivity of most novel 2d materials having been studied both theoretically and experimentally, the same is not true for 2d p-n junctions that are necessary blocks of most electronic devices. Here, we study the sub-terahertz photocoductivity of gapped bilayer graphene with electrically induced p-n junctions. We find a strong positive contribution from junctions to resistance, temperature resistance coefficient, and photoresistivity at cryogenic temperatures T similar to 20 K. The contribution to these quantities from junctions exceeds strongly the bulk values at uniform channel doping even at small band gaps of similar to 10 meV. We further show that positive junction photoresistance is a hallmark of interband tunneling, and not of intraband thermionic conduction. Our results point to the possibility of creating various interband tunneling devices based on bilayer graphene, including steep-switching transistors and selective sensors.