Highly DUV to NIR-II responsive broadband quantum dots heterojunction photodetectors by integrating quantum cutting...

Low-cost, high-performance, and uncooled broadband photodetectors (PDs) have potential applications in optical communication etc., but it still remains a huge challenge to realize deep UV (DUV) to the second near-infrared (NIR-II) detection for a single broadband PD. Herein, a single PD affording broadband spectral response from 200 to 1700 nm is achieved with a vertical configuration based on quantum dots (QDs) heterojunction and quantum cutting luminescent concentrators (QC-LC). A broadband quantum dots heterojunction as absorption layer was designed by integrating CsPbI₃:Ho³⁺ perovskite quantum dots (PQDs) and PbS QDs to realize the spectral response from 400 to 1700 nm. The QC-LC by employing CsPbCl₃:Cr³⁺, Ce³⁺, Yb³⁺, Er³⁺ PQDs as luminescent conversion layer to collect and concentrate photon energy for boosting the DUV-UV (200-400 nm) photons response of PDs by waveguide effect. Such broadband PD displays good stability, and outstanding sensitivity with the detectivity of 3.19 × 10¹² Jones at 260 nm, 1.05 × 10¹³ Jones at 460 nm and 2.23 × 10¹² Jones at 1550 nm, respectively. The findings provide a new strategy to construct broadband detector, offering more opportunities in future optoelectronic devices.