Semiconductors

Electronic structure of the valence band of gallium nitride during sodium adsorption

M. N. Lapushkin^a, A. M. Mizerov^b, S. N. Timoshnev<sup>b

a</sup> Ioffe Institute, St. Petersburg
^b Alferov Federal State Budgetary Institution of Higher Education and Science Saint Petersburg National Research Academic University of the Russian Academy of Sciences, St. Petersburg

Abstract: The electronic structure of the Na/GaN interface was studied using synchrotron radiation photoelectron spectroscopy in the photon energy range of 75 eV – 770 eV. To determine the physical properties of the GaN surface upon Na adsorption, the density of states was calculated using the density functional theory. The 2D GaN layer was modeled by a GaN(0001) 2 $\times$ 2 $\times$ 2 supercell containing 10 GaN bilayers. It was shown that the adsorption of Na atoms in the hollow position and over the surface N atoms is preferable, and the adsorption energies of sodium atoms are 1.96 eV and 1.93 eV, respectively. It was found that Na adsorption leads to the formation of surface states whose electron density is localized near the Fermi level.

Keywords: GaN, sodium, adsorption, photoelectron spectroscopy, density functional theory.

Received: 20.03.2025
Revised: 22.03.2025
Accepted: 24.03.2025

DOI: 10.61011/FTT.2025.04.60542.53-25

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