Analysis of AES of 2nd Period Element-containing Substances and Valence XPS of the Four Solid Ones by DFT Calculations Using the Model Molecules

Abstract

Experimental Auger electron spectra (AES) of 2nd period elements and valence X-ray photoelectron spectra (VXPS) of four solid substances [LiF, graphite, GaN, SiO2] are analyzed by density-functional theory (DFT) calculations using the model molecules of the unit cell. For the calculations, we use Gaussian09 program at B3LYP/6-31G (d, p) level to estimate VXPS, core-electron binding energies, and (Li ~ F)-KVV AES of the solid substances. In the AES simulations, we evaluate theoretical kinetic energies of the AES with our modified calculation method. The modified kinetic energies correspond to the final-state holes at the ground state in DFT calculations. Simulated KVV AES of the (Li ~ O) atoms with the maximum kinetic energies of the atoms agree considerably well to the experimental AES results. Calculated VXPS of the four substances are also in good accordance with the experimental ones. The kinetic energy formula of AES at the ground state appears to work better, despite its great simplicity.