Potassium iodide-doped cesium tin chloride/copper oxide perovskite for light photodetection and energy conversion

Perovskite materials have emerged as up-and-coming candidates for optoelectronic devices. This study developed a photodetector by depositing a halide double perovskite material, KI-doped Cs₂SnCl₆ (KI:CTC), onto a CuO substrate. Extensive analyses examined the photodetector's optical, structural, and morphological properties. The bilayer structure of KI:CTC exhibited a well-defined cubic crystal structure with a crystal size of 37.73 nm. The photodetector's band gap (<i>E</i> _g) was accurately measured to be 1.55 eV. The performance parameters of the KI:CTC/CuO photodetector were rigorously evaluated. At an incident photon wavelength of 390 nm, a remarkable photoresponsivity (PR) of 143.0 mA W^-1, an impressive specific detectivity (D*) of 7.95 × 10⁹ Jones, and a high external quantum efficiency (EQE) of 61.0% were achieved. Additionally, the stability and underlying mechanism of the photodetector were thoroughly discussed. The results suggest that the KI:CTC/CuO photodetector exhibits effective light detection, positioning it as a promising candidate for future optoelectronic applications.