Narrow Dual-Band Photodetector Based on Cs2AgBiBr6 Lead-Free Double Perovskite Single Crystal

Narrowband photodetectors play a vital role in imaging and sensing applications. Due to exceptional optoelectronic properties and tunable bandgap, perovskites are highly suitable for realizing narrowband photodetection. In this work, a narrow dual-band photodetector based on lead-free perovskite single crystal (PSC) Cs2AgBiBr6 is fabricated. The detector showed a narrowband response spectrum with dual bands with a peak response at 530 and 590 nm. A detectivity of 109 Jones with a full-width half maximum (FWHM) of 42 nm is achieved in both bands. The detector showed a rise time ( ${t}_{\text {r}}$ ) of 92 ms and a fall time ( ${t}_{\text {f}}$ ) of 271 ms under 530 nm illumination, along with a stable performance up to 25 days in ambient conditions. This attempt demonstrates a stable narrow dual-band photodetection using a lead-free Cs2AgBiBr6 double PSC for multispectral imaging applications.