Solution‐Grown Large‐Sized Single‐Crystalline 2D/3D Perovskite Heterostructure for Self‐Powered Photodetection

Abstract Organic–inorganic hybrid perovskite heterostructures, particularly 2D/3D perovskite heterostructures, have enjoyed great success in optoelectronic field. However, the photodetection performance of those heterostructures is obscured by extensive disorder in their polycrystalline films. Here, a delicate solution method is demonstrated for creating a sizable crystal of vertical 2D/3D perovskite heterostructure featuring a well‐defined interface and high single‐crystalline quality, namely (4‐AMP)(MA) 2 Pb 3 Br 10 /MAPbBr 3 (MA, methylammonium; 4‐AMP, 4‐(aminomethyl)piperidinium). These high‐quality crystals are ideal mediums for charge transport and exploiting their optoelectronic properties. Electrical transport measurements demonstrate that the (4‐AMP)(MA) 2 Pb 3 Br 10 /MAPbBr 3 heterostructure can form vertical diode with obvious current rectification behavior and excellent photocurrent generation characteristics. Strikingly, benefitting from the built‐in electrical potential at the junction, photodetectors based on those millimeter‐thickness heterostructure crystals exhibit high performance in self‐driven operation mode, including large on/off switching radio ( ≈ 10 5 ), fast response time (600/600 µ s), and high detectivity ( ≈ 10 12 ). This work enables an important advance in the development of single‐crystalline perovskite heterostructures for both fundamental demonstrations and high‐performance optoelectronic devices.