Probing and manipulating the Mexican hat-shaped valence band of In<sub>2</sub>Se<sub>3</sub>.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 39843916.
- Also identified by DOI 10.1038/s41467-025-56139-8 and PMC identifier 11754478.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
Ferroelectrics based on van der Waals semiconductors represent an emergent class of materials for disruptive technologies ranging from neuromorphic computing to low-power electronics. However, many theoretical predictions of their electronic properties have yet to be confirmed experimentally and exploited. Here, we use nanoscale angle-resolved photoemission electron spectroscopy and optical transmission in high magnetic fields to reveal the electronic band structure of the van der Waals ferroelectric indium selenide (α-In<sub>2</sub>Se<sub>3</sub>). This indirect bandgap semiconductor features a weakly dispersed valence band, which is shaped like an inverted Mexican hat. Its form changes following an irreversible structural phase transition of α-In<sub>2</sub>Se<sub>3</sub> into β-In<sub>2</sub>Se<sub>3</sub> via a thermal annealing in ultra-high vacuum. Density functional theory supports the experiments and reveals the critical contribution of spin orbit coupling to the form of the valence band. The measured band structure and its in situ manipulation offer opportunities for precise engineering of ferroelectrics and their functional properties beyond traditional semiconducting systems.