Single-Walled Carbon Nanotube Thin Film for Flexible and Highly Responsive Perovskite Photodetector

Metal–halide perovskites have recently shown tremendous progress in flexible photodetector applications owing to their great optical and electronic properties. However, apart from charge generating material, the high performance device requires a reasonable choice of electrodes for efficient carrier management as well. For example, the widespread use of gold and silver electrodes often results in perovskite device degradation while being expensive. Here, low‐cost and chemically inert single‐walled carbon nanotube (SWCNT) thin films are employed as electrodes to create highly responsive and flexible photodetector based on cesium lead tribromide (CsPbBr₃) microcrystals. Direct growth of the perovskite on SWCNT forms excellent contact between the components leading to the state‐of‐the‐art responsivity for flexible perovskite photodetectors 1321 A W⁻¹ at 5 V and under illumination intensity 1 mW cm⁻² at 505 nm wavelength. The advanced properties of SWCNT films realized on a flexible substrate allow for robust operation over 10⁴ cycles of device bending along with all parameters stability at ambient conditions for at least 1.5 months. The proposed design reveals the potential of SWCNT thin film electrodes for high performance perovskite flexible devices.