Single‐Crystalline Layered Metal‐Halide Perovskite Microwires with Intercalated Molecules for Ultraviolet Photodetectors

Abstract Intercalation regulation is a special way to tune the photophysical properties of perovskite without changing the organic cations. Here, it is found that dimethyl sulfoxide can be effectively intercalated into synthesized (OHC₆H₅CH₂CH₂NH₃)₂PbBr₄ perovskite through hydrogen bonds between organic spacer layers and solvent molecules. The new intercalated perovskite can be stored for more than two months under a relative humidity of about 60% at room temperature without encapsulation. The single crystal microwire array device based on this special structure presents photoelectric response of a light on/off ratio of 400 under 365 nm irradiation at 3 V. The device has a low dark current of 10⁻¹³ A. Moreover, the inserted solvent molecules can be removed from the perovskite or reinserted into the perovskite under different processing conditions. The results show the potential to regulate the optoelectronic properties of perovskites by reversibly binding intercalated molecules with perovskites.