Year: 2022
Type: preprint
Abstract: At the surfaces of materials, the bulk symmetry of the charge density is broken and electron spill-out into the vacuum region creates a surface dipole. Such spill-out has been historically calculated by Lang and Kohn [Phys. Rev. B \textbf{3}, 1215 (1971)] using average electron density to sucessfully explain the workfunction in metals. However, despite its initial success, in the fifty years since it has not been extended beyond simple metals. Here we show that the degree of charge spill-out is largely controlled by the innate bulk workfunction $ϕ_I$, which is the Fermi level position of $\it bulk$ relative to the ideal vacuum. By incorporating the contribution of $ϕ_I$ to the surface dipole we show that Lang-Kohn's $\it jellium$ based approach can be broadly expanded to understand the workfunction over a wide range of metals, semiconductors, and insulators.
Source: arXiv (Cornell University)
Authors: Jiang, Zeyu, West, Damien, Zhang, Shengbai
Institution: Rensselaer Polytechnic Institute
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W4296544109