Defect-induced doping and chemisorption of O2 in Se deficient GaSe monolayers
Year: 2025
Type: article
Abstract: Owing to their atomically thin nature, structural defects in two dimensional materials often play a dominating role in their electronic and optical properties. Here, we grow epitaxial GaSe monolayers on graphene/SiC by molecular beam epitaxy and characterise the layers by in situ scanning tunnelling microscopy and angle-resolved photoemission spectroscopy extracted from k-resolved photoemission electron microscopy mapping. We identify an electric dipole at the GaSe/graphene interface, with electrons accumulating on the GaSe, that cannot be compensated by p-type doping through the creation of defects formed by annealing in ultrahigh vacuum. Additionally, we demonstrate that both as-grown and defective GaSe layers are remarkably resilient to oxidation in a pure O2 environment, and chemisorption of O2 molecules on the surface can effectively electronically neutralise the doping in the layer. This work demonstrates the robust interlayer interaction in the GaSe/graphene van der Waals heterostructure and the role of defects on the doping for nanoelectronics.
Source: Figshare
Authors: Jonathan Bradford (5574503), Kazi Rahman (3915782), James Felton (20439680), Mustaqeem Shiffa (19271946), Tin S Cheng (19520908), Peter H Beton (8372670), Alex Saywell (1854496), Mark Greenaway (3135495), Sergei V Novikov (19520911), James N O'Shea (19520914), Amalia Patane (11324763)
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7073947417
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