Advanced optoelectronics require materials with newly engineered characteristics. Examples include a class of materials named metal-halide perovskites that have tremendous significance to form perovskite solar cells with photovoltaic efficiencies. Recent advances have also applied perovskite nanocrystals in light-emitting devices. The unusually efficient light emission of cesium lead-halide perovskite may be due to a unique excitonic fine structure made of three bright triplet states that minimally interact with a proximal dark singlet state. Excitons are electronic excitations responsible for the emissive properties of nanostructured semiconductors, where the lowest-energy excitonic state is expected to be long lived and hence poorly emitting (or ‘dark’).
Click here for original story, Multidimensional coherent spectroscopy reveals triplet state coherences in cesium lead-halide perovskite nanocrystals
Source: Phys.org