Fabrication and Characterization of a Textile-Based Low-Power Broadband Flexible Photodetector Using Lead-Free CH3NH3SnI3 Halide Perovskite

Abstract We report the development of a textile-based, flexible photodetector featuring low power consumption and broadband photoresponse, fabricated using a solution-processed, lead-free perovskite halide, methylammonium tin iodide (CH3NH3SnI3). The device leverages the mechanical flexibility and wearability of textile substrates while employing an environmentally friendly, lead-free perovskite to achieve efficient light detection. The photodetector exhibits a broad spectral response ranging from ultraviolet (UV) to near-infrared (NIR) (350−1000 nm), with enhanced responsivity in the NIR region owing to the material’s narrow bandgap. It functions effectively at low optical power densities (down to 0.05 μW/cm2) and low operating voltages (as low as 1 V), delivering optimal performance at 5 V with a peak responsivity of 38mA/W and a detectivity of approximately 3.6 × 1011 Jones at 900 nm. The device exhibits sublinear photocurrent dependence with increasing light intensity and maintains excellent mechanical flexibility and operational stability, with minimal performance degradation under repeated bending. The use of biodegradable cotton fabric as the substrate offers a sustainable platform for developing eco-friendly, low-power, wearable photodetectors with potential applications in healthcare monitoring, biomedical diagnostics, and next-generation smart textiles.