Highly Efficient and Stable Self-Powered Perovskite Photodiode by Cathode-Side Interfacial Passivation with Poly(Methyl Methacrylate).

For several years now, organic-inorganic hybrid perovskite materials have shown remarkable progress in the field of opto-electronic devices. Herein, we introduce a cathode-side passivation layer of poly(methyl methacrylate) (PMMA) for a highly efficient and stable self-powered CHNHPbI perovskite-based photodiode. For effective noise-current suppression, the PMMA passivation layer was employed between a light-absorbing layer of CHNHPbI (MAPbI) perovskite and an electron transport layer of [6,6]-phenyl-C61-butyric acid methyl ester. Due to its passivation effect on defects in perovskite film, the PMMA passivation layer can effectively suppress interface recombination and reduce the leakage/noise current. Without external bias, the MAPbI photodiode with the PMMA layer demonstrated a significantly high specific detectivity value (1.07 × 10 Jones) compared to that of a conventional MAPbI photodiode without a PMMA layer. Along with the enhanced specific detectivity, a wide linear dynamic response (127 dB) with rapid rise (50 μs) and decay (17 μs) response times was obtained. Furthermore, highly durable dynamic responses of the PMMA-passivated MAPbI photodiode were observed even after a long storage time of 500 h. The results achieved with the cathode-side PMMA-passivated perovskite photodiodes represent a new means by which to realize highly sensitive and stable self-powered photodiodes for use in developing novel opto-electronic devices.