Stable Graphene-Two-Dimensional Multiphase Perovskite Heterostructure Phototransistors with High Gain

Yuchuan Shao, Ye Liu, Xiaolong Chen, Chen Chen, Ibrahim Sarpkaya, Zhaolai Chen, Yanjun Fang, Jaemin Kong, Kenji Watanabe, Takashi Taniguchi, André Taylor, Jinsong Huang, Fengnian Xia

Research output: Contribution to journalArticlepeer-review


Recently, two-dimensional (2D) organic-inorganic perovskites emerged as an alternative material for their three-dimensional (3D) counterparts in photovoltaic applications with improved moisture resistance. Here, we report a stable, high-gain phototransistor consisting of a monolayer graphene on hexagonal boron nitride (hBN) covered by a 2D multiphase perovskite heterostructure, which was realized using a newly developed two-step ligand exchange method. In this phototransistor, the multiple phases with varying bandgap in 2D perovskite thin films are aligned for the efficient electron-hole pair separation, leading to a high responsivity of ∼105 A W-1 at 532 nm. Moreover, the designed phase alignment method aggregates more hydrophobic butylammonium cations close to the upper surface of the 2D perovskite thin film, preventing the permeation of moisture and enhancing the device stability dramatically. In addition, faster photoresponse and smaller 1/f noise observed in the 2D perovskite phototransistors indicate a smaller density of deep hole traps in the 2D perovskite thin film compared with their 3D counterparts. These desirable properties not only improve the performance of the phototransistor, but also provide a new direction for the future enhancement of the efficiency of 2D perovskite photovoltaics.

Original languageEnglish (US)
Pages (from-to)7330-7338
Number of pages9
JournalNano Letters
Issue number12
StatePublished - Dec 13 2017


  • Two-dimensional perovskite
  • graphene
  • photoconductive gain
  • phototransistors
  • stability

ASJC Scopus subject areas

  • Bioengineering
  • General Chemistry
  • General Materials Science
  • Condensed Matter Physics
  • Mechanical Engineering


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