• 文献标题:   Twisted graphene-assisted photocarrier transfer from HgSe colloidal quantum dots into silicon with enhanced collection and transport efficiency
  • 文献类型:   Article
  • 作  者:   TANG X, WU GF, LAI KWC
  • 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:   City Univ Hong Kong
  • 被引频次:   5
  • DOI:   10.1063/1.4986188
  • 出版年:   2017

▎ 摘  要

We report a strategy to realize and facilitate the photocarrier transport from mercury selenium colloidal quantum dots (HgSe CQDs) into silicon with the assistance of twisted graphene. A nanocomposite material consisting of HgSe CQDs and twisted graphene has been synthesized. By bringing the nanocomposites into contact with silicon, a HgSe CQD-twisted graphene nanocomposite/silicon junction was fabricated and demonstrated photoresponses in the long-wave infrared range. In the nanocomposites, the surface of twisted graphene was decorated with HgSe CQDs. Benefiting from the twisted structure in the nanocomposites, the active sensing area and light-matter interaction length are greatly increased. Driven by the interfacial built-in potential, photocarriers directly transfer from HgSe CQDs into the twist graphene, which serves as a fast carrier transport pathway to silicon, leading to high photocarrier collection efficiency. Compared with vertically stacked HgSe CQD film/flat graphene, the application of HgSe CQD-twisted graphene nanocomposites avoids photocarriers transporting via the hopping mechanism and over 2700% enhancement ratio of spectral responsivity was achieved, reaching 31.5mA/W@ 9 mu m. The interfacial energy band diagram was deduced for a better understanding of the photocarrier transfer process occurring at the interface between HgSe colloidal quantum dots, twist graphene, and silicon. Published by AIP Publishing.