Atomic structure and defect dynamics of monolayer lead iodide nanodisks with epitaxial alignment on graphene.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 32041958.
- Also identified by DOI 10.1038/s41467-020-14481-z and PMC identifier 7010709.
- 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
Lead Iodide (PbI<sub>2</sub>) is a large bandgap 2D layered material that has potential for semiconductor applications. However, atomic level study of PbI<sub>2</sub> monolayer has been limited due to challenges in obtaining thin crystals. Here, we use liquid exfoliation to produce monolayer PbI<sub>2</sub> nanodisks (30-40 nm in diameter and > 99% monolayer purity) and deposit them onto suspended graphene supports to enable atomic structure study of PbI<sub>2</sub>. Strong epitaxial alignment of PbI<sub>2</sub> monolayers with the underlying graphene lattice occurs, leading to a phase shift from the 1 T to 1 H structure to increase the level of commensuration in the two lattice spacings. The fundamental point vacancy and nanopore structures in PbI<sub>2</sub> monolayers are directly imaged, showing rapid vacancy migration and self-healing. These results provide a detailed insight into the atomic structure of monolayer PbI<sub>2</sub>, and the impact of the strong van der Waals interaction with graphene, which has importance for future applications in optoelectronics.