Two-dimensional α-In2Se3 field effect transistor for wide-band photodetection and non-volatile memory

Mechanically exfoliated two-dimensional α-In2Se3 flakes are used as the channel material in field effect transistors. N-type conduction with 0.14cm2Vs carrier mobility is reported. The good gate modulation and the pronounced hysteresis make the device suitable for a wide range of applications, from digital logics to memories. An order of magnitude current increase is observed under illumination by a blue light at the incident optical power of 19 nW. The devices can work as visible-to-infrared wide-band photodetectors with time response of few-hundred milliseconds, responsivity up to 40A/W and specific detectivity D*=5⋅1011Jones at low light intensity.