Perovskite/Polymer Hybrid Thin Films for High External Quantum Efficiency Photodetectors with Wide Spectral Response from Visible to Near-Infrared Wavelengths

The characteristics such as high charge carrier mobility, long diffusion length, low dark current, and sharp absorption edge of perovskites make the material ideal for realizing photodetection, that is, simultaneously fast and sensitive. However, narrow spectral (850 nm) response limits their application. Here, this study successfully demonstrates an integrated perovskite/polymer device structure based on perovskite/hybrid thin films for efficient light harvesting. The expansion of the photoresponse spectrum is achieved by selecting an appropriate low band gap polymer (poly(diketopyrrolopyrrole-terthiophene)), which has a wider response (950 nm). It can be seen that the resulting photodetectors (PDs) yield an external quantum efficiency of approximate to 70% over a 500-700 nm range, and the photoresponse extends to 950 nm, which is obviously wider than the photoresponse of perovskite-based PDs. Moreover, the dark current density of the hybrid PDs is more efficiently suppressed compared with polymer-based PDs. The reduced dark current enhances the detectivity and linear dynamic range of the fabricated hybrid PDs, which achieve values of 1013 Jones and 110 dB, respectively.