Perovskite Quantum Dots Embedded Composite Films Enhancing UV Response of Silicon Photodetectors for Broadband and Solar‐Blind Light Detection

Abstract In this work, the integration of in situ fabricated perovskite quantum dots embedded composite films (PQDCFs) as downshifting materials is first reported for enhancing the ultraviolet (UV) response of silicon (Si) photodetectors toward broadband and solar‐blind light detection. External quantum efficiency measurements show that the UV response of PQDCF coated Si photodiodes greatly improves from near 0% to at most of 50.6% ± 0.5% @ 290 nm. As compared to the calculated maximum value of 87%, the light coupling efficiency of the integrated device is determined to be 80%@395 nm, suggesting an efficient downshifting process. Furthermore, PQDCF is also successfully adapted for electron multiplying charge coupled device (EMCCD) based image sensor. The PQDCF coated EMCCD shows linear response with high‐resolution imaging under illumination at 360, 620, and 960 nm, implying the ability of broadband light detection in the UV, visible (VIS), and near infrared (NIR) region. Furthermore, a solar‐blind UV detection is demonstrated by integrating a solar‐blind UV filter with PQDCF coated EMCCD. In all, the use of PQDCF as luminescent downshifting materials provides an effective and low‐cost way to improve the UV response of Si photodetectors.