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 ≈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.