International Conference ''Mechanisms and Nonlinear Problems of Nucleation, Growth of Crystals and Thin Films'' dedicated to the memory of the outstanding theoretical physicist Professor V.V. Slezov (Proceedings) St. Petersburg, July 1-5, 2019 Semiconductors
Photoemission studies of the electronic structure of GaN grown by plasma assisted molecular beam epitaxy
Abstract:
The results of experimental studies of the electronic and photoemission properties of an epitaxial GaN layer grown on a SiC/Si(111) substrate by plasma assisted molecular beam epitaxy are presented. The electronic structure of the GaN surface and ultrathin Li/GaN interface was first studied in situ under ultrahigh vacuum conditions under different Li coverages. The experiments were performed using photoelectron spectroscopy with synchrotron radiation in the photon energy range of 75–850 eV. The photoemission spectra in the region of the valence band and surface states and the photoemission spectra from the N $1s$, Ga $3d$, Li $2s$ core levels were studied for different submonolayer Li coverages. It is established that Li adsorption causes significant changes in the general form of the spectra induced by charge transfer between the Li layer and the lower N and Ga layers. It is established that the GaN surface has predominantly N-polarity. The semiconductor character of the Li/GaN interface is shown.
Keywords:gallium nitride, valence band structure, photoelectron spectroscopy.