Atomic structure and defect dynamics of monolayer lead iodide nanodisks with epitaxial alignment on graphene

Journal article

Abstract Lead Iodide (PbI 2 ) is a large bandgap 2D layered material that has potential for semiconductor applications. However, atomic level study of PbI 2 monolayer has been limited due to challenges in obtaining thin crystals. Here, we use liquid exfoliation to produce monolayer PbI 2 nanodisks (30-40 nm in diameter and > 99% monolayer purity) and deposit them onto suspended graphene supports to enable atomic structure study of PbI 2 . Strong epitaxial alignment of PbI 2 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 2 monolayers are directly imaged, showing rapid vacancy migration and self-healing. These results provide a detailed insight into the atomic structure of monolayer PbI 2 , and the impact of the strong van der Waals interaction with graphene, which has importance for future applications in optoelectronics.

Authors: Sinha, S; Zhu, T; France-Lanord, A; Sheng, Y; Grossman, JC

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Nature Research
• Journal: Nature Communications
• Volume: 11
• Issue: 1
• Pages: 823-823
• Publication date: 2020-02-10
• DOI: 10.1038/s41467-020-14481-z
• EISSN: 2041-1723
• ISSN: 2041-1723
• Language: English
• Keywords: Lattice (music); Exfoliation joint; Optoelectronics; Nanotechnology; Monolayer; Crystallography; Semiconductor; Chemical physics; Vacancy defect; Epitaxy; Graphene; van der Waals force; Layer (electronics); Band gap; Physics; Molecule; Materials science; Chemistry