Cesium-mediated electron redistribution and electron-electron interaction in high-pressure metallic CsPbI<sub>3</sub>.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 36400789.
- Also identified by DOI 10.1038/s41467-022-34786-5 and PMC identifier 9674642.
- 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
Electron-phonon coupling was believed to govern the carrier transport in halide perovskites and related phases. Here we demonstrate that electron-electron interaction enhanced by Cs-involved electron redistribution plays a direct and prominent role in the low-temperature electrical transport of compressed CsPbI<sub>3</sub> and renders Fermi liquid (FL)-like behavior. By compressing δ-CsPbI<sub>3</sub> to 80 GPa, an insulator-semimetal-metal transition occurs, concomitant with the completion of a slow structural transition from the one-dimensional Pnma (δ) phase to a three-dimensional Pmn2<sub>1</sub> (ε) phase. Deviation from FL behavior is observed upon CsPbI<sub>3</sub> entering the metallic ε phase, which progressively evolves into a FL-like state at 186 GPa. First-principles density functional theory calculations reveal that the enhanced electron-electron coupling results from the sudden increase of the 5d state occupation in Cs and I atoms. Our study presents a promising strategy of cationic manipulation for tuning the electronic structure and carrier scattering of halide perovskites at high pressure.