Reversible 3D-2D structural phase transition and giant electronic modulation in nonequilibrium alloy semiconductor, lead-tin-selenide.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 33741599.
- Also identified by DOI 10.1126/sciadv.abf2725 and PMC identifier 7978423.
- 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
Material properties depend largely on the dimensionality of the crystal structures and the associated electronic structures. If the crystal-structure dimensionality can be switched reversibly in the same material, then a drastic property change may be controllable. Here, we propose a design route for a direct three-dimensional (3D) to 2D structural phase transition, demonstrating an example in (Pb<sub>1-<i>x</i></sub> Sn <i><sub>x</sub></i> )Se alloy system, where Pb<sup>2+</sup> and Sn<sup>2+</sup> have similar <i>n</i>s<sup>2</sup> pseudo-closed shell configurations, but the former stabilizes the 3D rock-salt-type structure while the latter a 2D layered structure. However, this system has no direct phase boundary between these crystal structures under thermal equilibrium. We succeeded in inducing the direct 3D-2D structural phase transition in (Pb<sub>1-<i>x</i></sub> Sn <i><sub>x</sub></i> )Se alloy epitaxial films by using a nonequilibrium growth technique. Reversible giant electronic property change was attained at <i>x</i> ~ 0.5 originating in the abrupt band structure switch from gapless Dirac-like state to semiconducting state.