Self‐Powered Broadband Photodetection With Open‐Circuit Voltage Exceeding 1 Volt via Template‐Guided Perovskite/MoS ₂ Heterojunctions

ABSTRACT Self‐powered photodetectors based on two‐dimensional materials and perovskite heterojunctions leverage quantum confinement and exceptional photoelectric conversion, yet poor interface contacts typically restrict open‐circuit voltage (V oc ) below 0.5 V, limiting low‐light applications. Here, we demonstrate an open‐circuit voltage exceeding 1 V and an ultralow dark current of 0.01 pA via an intimate MoS 2 /MAPbBr 3 heterojunction formed through in situ crystal‐on‐crystal growth. Carrier confinement in the two‐dimensional MoS 2 layer reduces the average dark current to 0.6 pA at 0.1 V, enabling zero‐bias broadband detection across 405–808 nm. The wavelength‐dependent V oc reveals a correlation between photogenerated carrier separation and perovskite absorption depth. The device delivers a responsivity of 33 mA W −1 , detectivity surpassing 10 11 Jones, and a noise‐equivalent power of 2.56 × 10 −15 W Hz 0.5 . These results establish a promising strategy for low‐power broadband detection and advance mixed‐dimensional heterojunctions for next‐generation optoelectronics.