Quantum dots enhanced UV response of silicon photodetectors for broadband light detection (Conference Presentation)

Abstract

Quantum dots have been considerred to be suitable candidates for down-shifting applications. The integration of quantum dots with Si photodetector provide low cost method to extend the reponse in the UV region. However, the lack of suitable processing technique reduce the reposne in visible region. In this work, we firstly report the integration of in-situ fabricated perovskite quantum dots embedded composite films (PQDCF) as down-shifting materials 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 improved 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 down-shifting process. Furthermore, PQDCF was 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 nm, 620 nm 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 was demonstrated by integrating a solar-blind UV filter with PQDCF coated EMCCD. In all, the use of PQDCF as luminescent down-shifting materials provides an effective and low-cost way to improve the UV response of Si photodetectors.