Ferroelectric-Gated InSe Photodetectors with High On/Off Ratios and Photoresponsivity

Li Liu; Liangmei Wu; Aiwei Wang; Hongtao Liu; Ruisong Ma; Kang Wu; Jiancui Chen; Zhang Zhou; Yuan Tian; Haitao Yang; Chengmin Shen; Lihong Bao; Zhihui Qin; Sokrates T Pantelides; Hong-Jun Gao

doi:10.1021/acs.nanolett.0c02448

Ferroelectric-Gated InSe Photodetectors with High On/Off Ratios and Photoresponsivity

Nano Lett. 2020 Sep 9;20(9):6666-6673. doi: 10.1021/acs.nanolett.0c02448. Epub 2020 Aug 26.

Authors

Li Liu^{1

2}, Liangmei Wu², Aiwei Wang², Hongtao Liu², Ruisong Ma², Kang Wu², Jiancui Chen², Zhang Zhou², Yuan Tian¹, Haitao Yang², Chengmin Shen^{2

3}, Lihong Bao^{2

3}, Zhihui Qin¹, Sokrates T Pantelides^{2

4}, Hong-Jun Gao^{2

3}

Affiliations

¹ Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education & Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices, School of Physics and Electronics, Hunan University, Changsha 410082, People's Republic of China.
² Institute of Physics & University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100190, People's Republic of China.
³ Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, People's Republic of China.
⁴ Department of Physics and Astronomy and Department of Electrical Engineering and Computer Science, Vanderbilt University, Nashville, Tennessee 37235, United States.

PMID: 32822183
DOI: 10.1021/acs.nanolett.0c02448

Abstract

Indium selenide (InSe) has a high electron mobility and tunable direct band gap, enabling its potential applications to electronic and optoelectronic devices. Here, we report the fabrication of InSe photodetectors with high on/off ratios and ultrahigh photoresponsivity, using ferroelectric poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) copolymer films as the top-gate dielectric. Benefiting from the successful suppression of the dark current down to ∼10^-14A in the InSe channel by tuning the three different polarization states in ferroelectric P(VDF-TrFE) and improved interface properties using h-BN as a substrate, the ferroelectric-gated InSe photodetectors show a high on/off ratio of over 10⁸, a high photoresponsivity up to 14 250 AW^-1, a high detectivity up to 1.63 × 10¹³ Jones, and a fast response time of 600 μs even at zero-gate voltage. The present results highlight the role of ferroelectric P(VDF-TrFE) in tuning the carrier transport of InSe and may provide an avenue for the development of InSe-based photodetectors.

Keywords: InSe; P(VDF-TrFE); ferroelectric; on/off ratios; photodetector; photoresponsivity.