The CsPbBr3 photodetector prepared by an in situ cation exchange method exhibits exceptional performance in terms of detectivity, responsivity, and response time. Once integrated into the laser eavesdropping system, it can skillfully capture the sound signals from distant targets, ultimately enabling the successful realization of laser eavesdropping through the mutual conversion of optical and electrical signals. Abstract Owing to the absence of organic cations, all‐inorganic perovskite exhibits superior thermal and irradiation stability compa...
