A dual strategy to enhance the photoelectric performance of Perovskite-Based photodetectors for potential applications in optical communications

The emerging metal halide perovskite photodetectors (PDs) attract extensive attention for optical communications due to their excellent photoelectric properties and are considered promising alternatives for the next generation of PDs. Here, we demonstrate high-performance MAPbI3 PDs based on the p-i-n structure for optical communications. A twofold approach is implemented to enhance the photoelectric performance and stability of the device. First, we introduce Au nanoparticles to reduce grain boundaries and defects, and increase the crystallinity of perovskite. Second, we use n-propylammonium iodide as an efficient recrystallization agent to decrease interface recombination and create a capping layer of a quasi-2D (PA)2PbI4 perovskite coating. This barrier layer also protects the underlying 3D perovskite film from degradation. The prepared PDs exhibit a high responsivity of 0.4 A/W, a response time of 7.58 µs, and an on/off current ratio of 2.0 × 105. In addition, the modified PDs present outstanding long-term environmental stability (>100 days) without encapsulation under ambient conditions. Finally, the PDs are successfully integrated into a visible light communication system to transmit ASCII-encoded information as an optical signal receiver. The results open up the possibility of developing high-speed and stable metal halide perovskite PDs that have potential for applications in optical communications.