Molecular engineering towards efficientwhite-light-emitting perovskite.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 34385451.
- Also identified by DOI 10.1038/s41467-021-25132-2 and PMC identifier 8361204.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Low-dimensional hybrid perovskites have demonstrated excellent performance as white-light emitters. The broadband white emission originates from self-trapped excitons (STEs). Since the mechanism of STEs formation in perovskites is still not clear, preparing new low-dimensional white perovskites relies mostly on screening lots of intercalated organic molecules rather than rational design. Here, we report an atom-substituting strategy to trigger STEs formation in layered perovskites. Halogen-substituted phenyl molecules are applied to synthesize perovskite crystals. The halogen-substituents will withdraw electrons from the branched chain (-R-NH<sub>3</sub><sup>+</sup>) of the phenyl molecule. This will result in positive charge accumulation on -R-NH<sub>3</sub><sup>+</sup>, and thus stronger Coulomb force of bond (-R-NH<sub>3</sub><sup>+</sup>)-(PbBr<sub>4</sub><sup>2-</sup>), which facilitates excitons self-trapping. Our designed white perovskites exhibit photoluminescence quantum yield of 32%, color-rendering index of near 90 and chromaticity coordinates close to standard white-light. Our joint experiment-theory study provides insights into the STEs formation in perovskites and will benefit tailoring white perovskites with boosting performance.