Large-area transparent flexible guanidinium incorporated MAPbI3 microstructures for high-performance photodetectors with enhanced stability.

Unveiling the transparency and flexibility in perovskite-based photodetectors with superior photoresponse and environmental stability remains an open challenge. Here we report on guanidinium incorporated metal halide perovskite (MA1-xGuaxPbI3, x = 0 to 0.65) random percolative microstructure (RPM) fabrication using an ultra-fast spray coating technique. Remarkably, RPMs over a large area of 5 × 5 cm2 on flexible substrates with a transparency of ∼50% can be achieved with enriched environmental stability. Transparent photodetectors based on MA1-xGuaxPbI3 (x = 0.12) RPMs manifest excellent performance with a responsivity of 187 A W-1, a detectivity of 2.23 × 1012 Jones and an external quantum efficiency of 44 115%. Additionally, the photodetectors exhibited superior mechanical flexibility under a wide range of bending angles and large number of binding cycles. Integrating features including transparency, high performance, stability, flexibility and scalability within a photodetector is unmatched and holds potential for novel applications in transparent and wearable optoelectronic devices.