On-Chip Weak-Light Detection Using a Monolithically Integrated Perovskite Photodetector Array on LNOI Waveguides

Inorganic perovskites are promising for photodetection due to their high stability and excellent optoelectronic characteristics. In this work, we present a high-performance on-chip photodetector array based on CsPbI₂Br films monolithically integrated with lithium-niobate-on-insulator (LNOI) waveguides. Operating at a wavelength of 638 nm under a 1 V bias, the device achieves a remarkable responsivity of 55 mA W⁻¹, an ultra-low dark current of 43 pA, and a high normalized photo-dark current ratio (NPDR) of 10⁹ W⁻¹. Excellent uniformity performance is demonstrated across the on-chip photodetectors array. These results underscore the synergistic combination of the perovskite's optoelectronic merits and their excellent compatibility with the LNOI platform, paving a promising path toward high-efficiency, low-cost, and scalable solutions for on-chip weak-light detection.