LAUSR

Ferroelectricity-induced self-powered photodetection has emerged as an indispensable branch of new optoelectronic devices. Organometallic perovskites that combine ferroelectricity and semiconductor merits are promising. However, it remains a challenge to achieve self-powered photodetection with a low detection limit, due to the polarization deterioration caused by the leakage current of photoexcited carriers. Here, we exploit the high performance self-powered photodetection in the 2D perovskite ferroelectric, (C4H9NH3)2(NH2CHNH2)Pb2Br7 (1), driven by the switchable spontaneous polarization. Most strikingly, an extremely low detection limit of 82 nW cm−2 is achieved, far superior to those of many classical p–n junctions. Further studies disclose that such self-powered behaviors of 1 are related to its inherent photovoltaic effects, stemming from inversion symmetry breaking by ferroelectric polarization. This result advances the future potential of hybrid perovskite ferroelectrics as smart photoelectric devices.