Efficient Luminescent Halide Quadruple-Perovskite Nanocrystals via Trap-Engineering for Highly Sensitive Photodetectors

The colloidal synthesis of a new type of lead-free halide quadruple-perovskite nanocrystals (NCs) is reported. The photoluminescence quantum yield and charge-carrier lifetime of quadruple-perovskite NCs can be enhanced by 96 and 77-fold, respectively, via metal alloying. Study of charge-carrier dynamics provide solid demonstrate that the PL enhancement is due to the elimination of ultrafast (1.4 ps) charge-carrier trapping processes in the alloyed NCs. Thanks to the high crystallinity, low trap-state density, and long carrier lifetime (193.4 mu s), the alloyed quadruple-perovskite NCs can serve as the active material for high-performance photodetectors, which exhibit high responsivity (up to 0.98 x 10(4) A W-1) and an external quantum efficiency (EQE) of 3 x 10(6)%. These numbers are among the highest for perovskite-NC-based photodetectors.

Automated summary

The colloidal synthesis of a new type of lead-free halide quadruple-perovskite nanocrystals is reported. The photoluminescence quantum yield and charge-carrier lifetime of quadruple-perovskite NCs can be enhanced by metal alloying, leading to high-performance photodetectors with high responsivity and external quantum efficiency.