Ultrafast Excited-State Localization in Cs₂AgBiBr₆ Double Perovskite.

ABSTRACT: Cs₂AgBiBr₆ is a promising metal halide double perovskite offering the possibility of efficient photovoltaic devices based on lead-free materials. Here, we report on the evolution of photoexcited charge carriers in Cs₂AgBiBr₆ using a combination of temperature-dependent photoluminescence, absorption and optical pump-terahertz probe spectroscopy. We observe rapid decays in terahertz photoconductivity transients that reveal an ultrafast, barrier-free localization of free carriers on the time scale of 1.0 ps to an intrinsic small polaronic state. While the initially photogenerated delocalized charge carriers show bandlike transport, the self-trapped, small polaronic state exhibits temperature-activated mobilities, allowing the mobilities of both to s

SUBMITTER: Wright AD 

PROVIDER: S-EPMC8154850 | biostudies-literature | 2021 Apr

REPOSITORIES: biostudies-literature