Spin-enabled photochemistry using nanocrystal-molecule hybrids

Research interest in the spin properties of lead halide perovskites has been rising in recent years in the hope of using solution-processed materials for scalable implementation of spintronics and quantum information technologies. However, very short spin lifetimes are often found for these systems, suggesting a long way to go along this direction. Here, we propose that these short spin lifetimes can instead find immediate applications in molecular photochemistry that largely relies on spin-relaxed triplet excited states. We demonstrated this using CsPbBr3 nanocrystals interfaced with rhodamine B (RhB) molecules. Photoexcitation of RhB led to hole injection into nanocrystals; rapid hole spin-flip and subsequent recombination of the charge-separated states efficiently populated RhB triplets. Photoexcitation of CsPbBr3 nanocrystals also produced RhB triplets through a similar mechanism. Because of the complementary spectral coverage of CsPbBr3 and RhB, we achieved efficient white-light-driven triplet-fusion photon upconversion and singlet-oxygen generation using triplets from the nanocrystal-molecule hybrids.

Automated summary

Research interest in the spin properties of lead halide perovskites has been rising in recent years. However, these systems often have very short spin lifetimes. Nonetheless, these short spin lifetimes can find immediate applications in molecular photochemistry.