Photoresponse of graphene field-effect-transistor with n-type Si depletion layer gate

Shiho Kobayashi; Yuki Anno; Kuniharu Takei; Takayuki Arie; Seiji Akita

doi:10.1038/s41598-018-22974-7

Photoresponse of graphene field-effect-transistor with n-type Si depletion layer gate

Sci Rep. 2018 Mar 19;8(1):4811. doi: 10.1038/s41598-018-22974-7.

Authors

Shiho Kobayashi¹, Yuki Anno¹, Kuniharu Takei¹, Takayuki Arie¹, Seiji Akita²

Affiliations

¹ Department of Physics and Electronics, Osaka Prefecture University, Sakai, 599-8531, Japan.
² Department of Physics and Electronics, Osaka Prefecture University, Sakai, 599-8531, Japan. akita@pe.osakafu-u.ac.jp.

Abstract

Graphene/semiconductor Schottky junctions are an emerging field for high-performance optoelectronic devices. This study investigates not only the steady state but also the transient photoresponse of graphene field-effect transistor (G-FET) of which gate bias is applied through the Schottky barrier formed at an n-type Si/graphene interface with a thin oxide layer, where the oxide thickness is sufficiently thin for tunneling of the charge carrier. To analyze the photoresponse, we formulate the charge accumulation process at the n-Si/graphene interface, where the tunneling process through the SiO_x layer to graphene occurs along with recombination of the accumulated holes and the electrons in the graphene at the surface states on the SiO_x layer. Numerical calculations show good qualitative agreement with the experimentally obtained results for the photoresponse of G-FET.