• 文献标题:   Graphene/SnS2 van der Waals Photodetector with High Photoresponsivity and High Photodetectivity for Broadband 365-2240 nm Detection
  • 文献类型:   Article
  • 作  者:   ZHAO Y, TSAI TY, WU G, COILEAIN CO, ZHAO YF, ZHANG D, HUNG KM, CHANG CR, WU YR, WU HC
  • 作者关键词:   sns2, graphene, van der waals heterostructure, broadband photodetector, photogating effect, negative photoconductance effect
  • 出版物名称:   ACS APPLIED MATERIALS INTERFACES
  • ISSN:   1944-8244 EI 1944-8252
  • 通讯作者地址:  
  • 被引频次:   11
  • DOI:   10.1021/acsami.1c11534 EA SEP 2021
  • 出版年:   2021

▎ 摘  要

The fabrication of graphene/SnS2 van der Waals photodetectors and their photoelectrical properties are systematically investigated. It was found that a dry transferred graphene/SnS2 van der Waals heterostructure had a broadband sensing range from ultraviolet (365 nm) to near-infrared (2.24 mu m) and respective improved responsivities and photodetectivities of 7.7 x 10(3) A/W and 8.9 x 10(13) jones at 470 nm and 2 A/W and 1.8 x 10(10) jones at 1064 nm. Moreover, positive and negative photoconductance effects were observed when the photodetectors were illuminated by photon sources with energies greater and smaller than the bandgap of SnS2, respectively. The photoresponsivity (R) versus incident power density (P) follows the empirical law R proportional to P-in(beta), with beta > -1 for positive photoconductance effects and beta < -1 for negative photoconductance effects. On the basis of the Fowler-Nordheim tunneling model and a Poisson and drift-diffusion simulation, we show quantitatively that the barrier height and barrier width of the heterostructure photodetector could be controlled by a laser and an external electrical field through a photogating effect generated by carriers trapped at the interface, which could be used to tune the separation and transport of photogenerated carriers. Our results may be useful for the design of high performance van der Waals heterojunction photodetectors.