On the absence of a phonon bottleneck in strongly confined CsPbBr₃ perovskite nanocrystals.

ABSTRACT: In traditional solar cells, photogenerated energetic carriers (so-called hot carriers) rapidly relax to band edges via emission of phonons, prohibiting the extraction of their excess energy above the band gap. Quantum confined semiconductor nanocrystals, or quantum dots (QDs), were predicted to have long-lived hot carriers enabled by a phonon bottleneck, i.e., the large inter-level spacings in QDs should result in inefficient phonon emissions. Here we study the effect of quantum confinement on hot carrier/exciton lifetime in lead halide perovskite nanocrystals. We synthesized a series of strongly confined CsPbBr₃ nanocrystals with edge lengths down to 2.6 nm, the smallest reported to date, and studied their hot exciton relaxation using ultrafast spectroscopy. We ob

SUBMITTER: Li Y 

PROVIDER: S-EPMC6566378 | biostudies-literature | 2019 Jun

REPOSITORIES: biostudies-literature