title: Epitaxial Growth of Large-Grain NiSe Films by Solid-State Reaction for High-Responsivity Photodetector Arrays.
abstract: Film-based photodetectors have shown superiority for the fabrication of photodetector arrays, which are desired for integrating photodetectors into sensing and imaging systems, such as image sensors. But they usually possess a low responsivity due to low carrier mobility of the film consisting of nanocrystals. Large-grain semiconductor films are expected to fabricate superior-responsivity photodetector arrays. However, the growth of large-grain semiconductor films, normally with a nonlayer structure, is still challenging. Herein, this study introduces a solid-state reaction method, in which the growth rate is supposed to be limited by diffusion and reaction rate, for interface-confined epitaxial growth of nonlayer structured NiSe films with grain size up to micrometer scale on Ni foil. Meanwhile, patterned growth of NiSe films allows the fabrication of NiSe film based photodetector arrays. More importantly, the fabricated photodetector based on as-grown high-quality NiSe films shows a responsivity of 150 A W-1in contrast to the value of 0.009 A W-1from the photodetector based on as-deposited NiSe film consisting of nanocrystals, indicating a huge responsivity-enhancement up to four orders of magnitude. It is ascribed to the enhanced charge carrier mobility in as-grown NiSe films by dramatically decreasing the amount of grain boundary leading to scattering of charge carrier.
authors.affiliation: School of Materials Science and Engineering, Hefei University of Technology, Tunxi Road 193, Hefei, 230009, P. R. China.
authors.forename: Caoyuan
authors.initials: C
authors.lastname: Cai
authors.affiliation: School of Materials Science and Engineering, Hefei University of Technology, Tunxi Road 193, Hefei, 230009, P. R. China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Ma
authors.affiliation: SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University (SKKU), Suwon, 440-746, South Korea.
authors.forename: Jaeho
authors.initials: J
authors.lastname: Jeon
authors.affiliation: School of Materials Science and Engineering, Hefei University of Technology, Tunxi Road 193, Hefei, 230009, P. R. China.
authors.forename: Fan
authors.initials: F
authors.lastname: Huang
authors.affiliation: School of Materials Science and Engineering, Hefei University of Technology, Tunxi Road 193, Hefei, 230009, P. R. China.
authors.forename: Feixiang
authors.initials: F
authors.lastname: Jia
authors.affiliation: SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University (SKKU), Suwon, 440-746, South Korea.
authors.forename: Shen
authors.initials: S
authors.lastname: Lai
authors.affiliation: School of Materials Science and Engineering, Hefei University of Technology, Tunxi Road 193, Hefei, 230009, P. R. China.
authors.forename: Zhihao
authors.initials: Z
authors.lastname: Xu
authors.affiliation: School of Materials Science and Engineering, Hefei University of Technology, Tunxi Road 193, Hefei, 230009, P. R. China.
authors.forename: Congjun
authors.initials: C
authors.lastname: Wu
authors.affiliation: School of Material Science and Engineering, Henan Polytechnic University, Henan, 454000, China.
authors.forename: Ruiqi
authors.initials: R
authors.lastname: Zhao
authors.affiliation: National Laboratory of Solid-State Microstructures and Department of Materials Science and Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China.
authors.forename: Yufeng
authors.initials: Y
authors.lastname: Hao
authors.affiliation: School of Materials Science and Engineering, Hefei University of Technology, Tunxi Road 193, Hefei, 230009, P. R. China.
authors.forename: Yiqing
authors.initials: Y
authors.lastname: Chen
authors.affiliation: SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University (SKKU), Suwon, 440-746, South Korea.
authors.forename: Sungjoo
authors.initials: S
authors.lastname: Lee
authors.affiliation: School of Materials Science and Engineering, Hefei University of Technology, Tunxi Road 193, Hefei, 230009, P. R. China.
authors.forename: Min
authors.initials: M
authors.lastname: Wang
keywords: films; high responsivity; large grain; photodetector arrays; solid-state reactions