Quantum-Dots-In-Double-Perovskite for High-Gain Short-Wave Infrared Photodetector

Short-wave infrared (SWIR) photodetectors utilizing quantum dot (QD) material systems, harnessed through the quantum confinement effect to tune the absorption wavelength, offer an attractive avenue for the development of cost-effective and solution-processed photodetectors compared to the relatively expensive compound semiconductor photodetectors. However, the pores between the QDs and poor chemical stability after surface modification have impeded the practical application of quantum-dot-based photodetectors. In this study, high-gain SWIR photodetector is demonstrated and achieved by incorporating PbS QD into the Cs₂AgBiBr₆ halide-based double perovskite matrix, as confirmed by X-ray diffraction, transmission electron microscope, and energy dispersive spectrometer. The thin film structure and detailed local structure are revealed by 2D grazing-incidence wide and small-angle X-ray scattering. The resulting PbS@Cs₂AgBiBr₆-based SWIR photodetector exhibits remarkable performance with a responsivity and detectivity of 15000 A W⁻¹ and 1.31 × 10¹² cm Hz^1/2 W⁻¹, respectively. This study offers valuable insights into the design of composite materials for high-gain SWIR photodetectors.