Radiation stability and in situ electrical stress healing of photodetection performance on α-In₂Se₃ based transistors

In this work, α-In2Se3 based transistors with channel widths of 20 μm have been irradiated with⁶⁰Co γ-rays. The radiation induced photoresponsivity degradation, radiation stability, and time annealing effect on α-In2Se3 based transistor have been investigated. Both the radiation induced domain evolution and the time annealing effect decrease the photoresponsivity of α-In2Se3 based transistor. Phonon modes, domain structure, and surface topography of the α-In2Se3 nanoflakes have been investigated in details for revealing the mechanism of the photoresponsivity degradation. The results show that the surface topography damage of α-In2Se3 may be the main factor affecting the radiation stability in the time annealing. It is very interesting that the in-situ electric stress can heal the photoresponsivity decreased by the time annealing effect, because the captured free carriers can be freed by the voltage sweeping. Considering that the α-In2Se3 based transistors can still be used as photodetectors after an irradiation of 1 Mrad(Si) and a time annealing of one year, αIn2Se3 is promising for photodetector in extreme environmental conditions.