Air‐Stable and Self‐Driven Perovskite Photodiodes with High On/Off Ratio and Swift Photoresponse

Abstract

Abstract Recent years have witnessed rapid developments in organic–inorganic hybrid perovskites, among which 2D Ruddlesden–Popper (RP) perovskites stand out due to their outstanding ambient stability. In photodetector applications, 2D RP perovskites are mostly limited to lateral device configuration because of their preferred in‐plane charge transportation within quantum well structures. In this work, the low‐temperature solution construction of 2D RP perovskite‐based photodiodes in vertical device architecture is demonstrated. The paradigm phenylethylamine (PEA) spacer cation‐based 2D perovskites are fabricated and optimized by exploiting a combination of a NH 4 Cl additive and dimethyl sulfoxide solvent (DMSO) solvent. They show increased crystallinity, extended photoluminescence lifetimes, and importantly a generation of 3D phases embedded within 2D perovskites, which efficiently promotes charge transfer. As a result, the photodetectors exhibit a high on/off ratio up to 2 × 10 4 , a large photocurrent of 0.34 mA cm −2 , and rapid rise (5.8 ms) and decay time (4.6 ms). Of critical importance is the outstanding film/device stabilities demonstrated by storage in air (at 25 °C with 60% relative humidity) for 15 days as well as under UV illumination for 1.5 h and after 1500 bending cycles on flexible substrate.