An Extrinsic Approach Toward Achieving Fast Response and Self-Powered Photodetector

An extrinsic approach toward achieving fast response and self-powered photodetector is reported. It is shown that an organic-inorganic hybrid device (SnSe2/PEDOT:PSS) not only operates in self-powered mode for infra-red photodetection but also improves the response time with respect to inorganic (SnSe2) linear devices. Fast response and recovery time constants of approximate to 1.33 and 1.22 s, respectively, are obtained. Furthermore, the sensitivity is highest at zero bias and the device is stable for over 6 months stored in open air condition. The observed photo-current, faster response and recovery time constants are ascribed to the formation of a strong built-in electric field at the interface between SnSe2 and PEDOT:PSS. In a broader view of these findings, the device proves its potential as a self-powered photo-detector and the results reported here can pave the way to design self-powered and fast response for other wavelengths