Powder-polymer composite matrices for wafer-scale and flexible perovskite photodetectors

Single-crystal (SC) structures have long been regarded as the optimal configuration for metal halide perovskite photodetectors (PDs); however, their applications in large-area imaging and wearable electronics face limitations due to size constraints and mechanical inflexibility. To address these challenges, this study develops a hybrid composite structure—polycrystalline powder (PCP) matrix (PCPM)—by strategically homogenizing 20 μm PCPs within a poly(methyl methacrylate) matrix. Such a configuration enables the formation of densely packed PCP microstructures while maintaining electric conductivity and mechanical flexibility. In the single-photon regime, responsivity (R) and external quantum efficiency (EQE) decline by 50%, with concurrent 3–4-fold enhancements in the On/Off ratio and 12–16-fold improvements in specific detectivity (D), compared with those of SC counterparts. Notably, in the two-photon regime, R and EQE exhibit a 2–3-fold increase, and the On/Off ratio and D exhibit 12–16-fold improvements. The PCPM configuration enables the high-repetition-rate wafer-scale fabrication of active layers for imaging PDs and provides exceptional mechanical flexibility and self-recovery. These findings establish PCPMs as a scalable platform for next-generation perovskite wearable electronics.