Efficient quantum cutting of lanthanum and ytterbium ions co-doped perovskite quantum dots towards improving the ultraviolet response of silicon-based photodetectors

High-efficiency quantum cutting materials have great application prospects in improving the photoelectric conversion efficiency of silicon-based photoelectric devices. Herein, La3+ and Yb3+ ions co-doped CsPbCl3 perovskite quantum dots (PQDs) were prepared successfully via the modified hot-injection method. La3+ and Yb3+ ions codoping makes the PLQY of CsPbCl3 PQDs increase from 5% to 168%. This is because Yb3+ ions doping makes the effective quantum cutting process happen, as well as La3+ ions doping effectively reduces non-radiative transition in CsPbCl3 PQDs and further improves the quantum cutting efficiency. Finally, La3+ and Yb3+ ions co-doped CsPbCl3 PQDs film were integrated on silicon-based photodetectors. The spectral range of silicon-based photodetectors is extended to the ultraviolet (UV) region (200–400 nm) besides the visible spectral region. The external quantum efficiency (EQE) is around 67%, and the responsivity is 0.14 A/W, which is comparable to the highest value previously reported. This work provides a new strategy to improve the quantum cutting efficiency and the performance of silicon-based photodetectors.