Boosting UV responsivity of silicon photodetectors through efficient quantum-cutting with La3+, Yb3+co-doped perovskite quantum dots

Quantum cutting involves the absorption of a single high-energy photon, followed by the release of its energy through the emission of two or more lower-energy photons. This approach holds promise as a method to improve the ultraviolet (UV) performance of silicon photodetectors (Si PDs). In this study, we successfully fabricated La3+, Yb3+ co-doped CsPbClBr2 perovskite quantum dots (PQDs) using a modified hot-injection method, achieving a remarkable photoluminescent quantum yields (PLQYs) of 181 %. Subsequently, we spin-coated a film of La3+, Yb3+ co-doped CsPbClBr2 PeQDs, serving as a light conversion material, onto the front surface of Si PDs. The resulting configuration exhibited enhanced responsivity (0.131 A/W) and external quantum efficiency (55.6 %), long-term stability at 360 nm, and expanded responsiveness into the deep UV region (200 nm). Simultaneously, the responsivity and external quantum efficiency in the visible and near-infrared regions exhibited minimal reduction. This significant performance can be attributed to two key factors: (1) The higher efficient quantum cutting PLQYs (181 %) of La3+, Yb3+ co-doped CsPbClBr2 PeQDs and (2) the presence of fewer traps and a larger tolerance factor resulting from La3+ and Yb3+ co-doping.