High-Sensitivity and Fast-Response Photomultiplication Type Photodetectors Based on Quasi-2D Perovskite Films for Weak-Light Detection

Photovoltaic photodiodes often face challenges in effectively harvesting electrical signals, especially when detecting faint light. In contrast, photomultiplication type photodetectors (PM-PDs) are renowned for their exceptional sensitivity to weak signals. Here, an advanced PM-PD is introduced based on quasi 2D Ruddlesden-Popper (Q-2D RP) perovskites, optimized for weak light detection at minimal operating voltages. The abundant traps at the Q-2D RP surface capture charge carriers, inducing a trap-assisted tunneling mechanism that leads to the photomultiplication (PM) effect. Deep-lying trap states within the Q-2D RP bulk accelerate charge carrier recombination, resulting in an outstanding rise/fall time of 1.14/1.72 mu s for the PM-PDs. The PM-PD achieves a remarkable response level of up to 45.89 A W-1 and an extraordinary external quantum efficiency of 14400% at -1 V under an illumination of 1 mu W cm-2. The intrinsic high resistance of the Q-2D perovskite results in a low dark current, enabling an impressive detectivity of 4.23 x 1012 Jones based on noise current at -1 V. Furthermore, the practical application of PM-PDs has been demonstrated in weak-light, high-rate communication systems. These findings confirm the significant potential of PM-PDs based on Q-2D perovskites for weak light detection and suggest new directions for developing low-power, high-performance PM-PDs for future applications. An advanced photomultiplication-type photodetector based on quasi 2D Ruddlesden-Popper (Q-2D RP) perovskites is developed, specifically optimized for the detection of faint light signals even at minimal operating voltages. The high-density surface defects within the Q-2D RP perovskites contribute to the photomultiplication effect, while the deep energy level traps facilitate rapid carrier recombination, resulting in an ultra-fast response speed. image