Self-powered photodetector based on copper-doped methyl ammonium lead bromide

Emerging applications in internet of things are ushering research into novel device architectures for self-powered electronics. Pure and copper-doped CH₃NH₃PbBr₃ was synthesized using emulsion–DEemulsion process and subsequently using spin coating method, thin films were grown. Structural and optical characterization of the films were carried out before and after subjecting them to vacuum annealing. The copper-doped CH₃NH₃PbBr₃ thin films subjected to vacuum annealing at 400 K showed highest preferential orientation along the (113) growth plane. The characteristic green luminescence of the CH₃NH₃PbBr₃ system did not undergo any significant change in its photoluminescence emission energy indicating that copper doping or vacuum annealing of the copper-doped thin films does not alter the photoluminescence pathway. The time-resolved photoluminescence measurements of the samples showed that the electron–hole pair recombination lifetime varied from 10^–6 s for the pure material to 10^–10 s for the copper-doped vacuum-annealed material. We have engineered and characterized self-powered photodetectors using the copper-doped methyl ammonium lead bromide perovskite material which exhibits giant photosensitivity of 444%. Vacuum-annealed CH₃NH₃Pb_1−xCu_xBr₃-based photodetectors yield improved photocurrent and spectral response both in the UV and in the visible region delivering an effective increase in responsivity bandwidth relative to their pristine counterparts. The CH₃NH₃Pb_1−xCu_xBr₃-based photodetectors exhibit a self-powered ON/OFF photocurrent ratio of ~ 35, a detectivity of ~ 21 × 10⁵ Jones and responsivity of 8.244 × 10^–6 A/W.