Stable Self-Powered Broadband Photodetector Based on Triple-Cation Perovskite with n–i–p Architecture

Perovskite-based photodetectors have recently attracted widespread attention due to their excellent optoelectronic characteristics; however, their broader implementation remains hindered by limited long-term stability. In the present work, a solution-processed route is employed to fabricate a stable n–i–p architecture CsMAFAPb(IBr) 3 -based self-powered photodetector (SPPD). The optimized device achieved a responsivity of 0.2539A W –1 at 700 nm along with a specific detectivity of 3.002 × 10 11 Jones at the same wavelength. In addition, the device delivered a maximum external quantum efficiency (EQE) of nearly 60%, a broad linear dynamic range of 82 dB, and an on–off ratio of 1.35 × 10 4 under zero-bias operation. The fabricated photodetector also demonstrated promising operational stability, exhibiting an average decrease of approximately 50% in responsivity, EQE, and detectivity after 94 days (∼2256 h) under ambient conditions, which may be attributed to improved crystallinity and grain uniformity of the active perovskite layer. The reduced recombination losses are inferred from the observed optical and structural characteristics. Moreover, the photocurrent versus time ( I – t ) characteristics monitored over the same duration revealed nearly 60% degradation after 94 days.