A Highly Stable Photodetector Based on a Lead-Free Double Perovskite Operating at Different Temperatures

In recent years, considerable breakthroughs have been achieved in the explored photodetectors with improved performance and stability. However, such devices suffer from the drifting parameters (photoresponsivity, response time, and specific detectivity) in the case of evident operating temperature changes. Here, a double perovskite Cs₂NaBiCl₆-based ultraviolet (UV) photodetector is developed free from thermal disturbance, exhibiting a steady photoresponsivity (≈ 67.98 mA/W) and response time (≈ 16.42 ms) within a wide temperature range (from 273 to 333 K). Further studies demonstrate that the stability of the crystal structure endows the superior photodetection capability. This result unambiguously highlights the great potential of such double perovskite Cs₂NaBiCl₆ compound as an environmentally friendly alternative for UV photodetectors.