Photodetector based on liquid phase exfoliated SnSe quantum dots

Tremendous progress has been made in production of high-performance electronics and opto-electronics based on 2D-TMCs (Transition metal chalcogenides) due to their exotic band structure and unique physical properties. Herein, SnSe QDs, synthesized by liquid phase exfoliation, has an average size of 6 nm. Photodetector based on Ag/SnSe QDs/Ag shows non-ohmic charge transport with photoconducting behavior in visible to NIR spectral region. Photodetector shows quite distinct time resolved photoresponse with photoresponsivity of 401 μA/W in ambient environment and 36 μA/W in vacuum (10−3 torr) in illumination of 780 nm, 6 mW/cm2 light. Photoresponse with power law Iph α P0.7 shows that the photoresponse of detector is limited by defects in SnSe QDs. Photoswitching action is quite fast in vacuum than in ambient environment. Overall, the present findings demonstrate the influence of environmental oxygen on function of Ag/SnSe QDs/Ag photodetector.