Auger Electron Spectroscopy, Electron Energy Loss Spectroscopy, UV Photoelectron Spectroscopy, and Photoluminescence Characterization of In₂O₃ Associated to the Theoretical Calculations Based on the Generalized Gradient Approximation and Modified Becke Johnson

Abstract

The indium oxide In2O3 is among the transparent conducting oxides (TCO) appropriate for solar cells and optoelectronics. The physical properties are based on the electron distribution on the core levels and in the valence band of material. The knowledge of the electron distribution on the different states is fundamental to predict the possibilities of electron transitions. In this respect, we adopt calculations based on the generalized gradient approximation (GGA) and modified Becke Johnson (mBJ) to show the electron state density. We associate to the numerical simulation the experimental analysis techniques auger electron spectroscopy (AES), electron energy loss spectroscopy (EELS), and UV photoelectron spectroscopy (UPS) of great sensitivity to characterize the material surfaces. The analysis technique AES is used for proving the chemical composition of the In2O3 compound through the In-M45N45N45 and O-KLL signals. The energy loss peak at 16.3 eV on the EELS spectra is related to plasmons. The energy losses lower than 16.3 eV are related to interband transitions (ITs). They arise from the hybridation of states (s, p, and d) of indium and (s, p) of oxygen. The energy loss at 19 eV is mainly related to IT transition from the d states of indium in hybridation with a slight contribution of p and s states of indium and oxygen. The calculation is useful to predict the states from which the interband transitions occur. The EELS associated with UPS constitutes powerful techniques to show the energy states of the electron distribution. The irradiation of In2O3 by the UV photons at 320 nm leads to the photoluminescence emission at low energy around 580 nm, appropriate to laser applications.

Crystallisation Phenomena of In2O3:H Films

“…We applied energy filtered TEM to detect metallic indium, as it exhibits a bulk plasmon with an energy of about 12 eV [39]. The plasmonic spectrum of In 2 O 3 [40] could not be observed in this study. The set of TEM images obtained at distinct loss energies is presented in the Supplementary Materials (Figure S3).…”

Lattice dynamic stability and electronic structures of ternary hydrides La1−xYxH3via first-principles cluster expansion

“…Thus, we opt for the modified Becke–Johnson (mBJ) exchange potential 35 in conjunction with the GGA functional, owing to the fact that the former determines band gaps even of strongly correlated systems with an acceptable level of accuracy, yet with fewer resources compared to HSE06. 48–51 According to Fig. 4(b), the band dispersion of the I 4/ m structure, calculated by the mBJ exchange potential, clearly indicates a semiconducting phase with an indirect energy gap of 0.346 eV, whereas it is 0.252 eV in the case of the I 4/ mmm structure (Fig.…”

Hot Electrons in TiO2–Noble Metal Nano-Heterojunctions: Fundamental Science and Applications in Photocatalysis

“…With hot electrons, AES and EELS can provide information on chemical elements on the surface of a solid, the relevant binding energies, the density of states of the valence band, etc. [ 174 ] Furthermore, energy loss spectra can provide information on the discrete excitation-relaxation processes that occur upon LSPR dephasing, concerning nanoscale systems as opposed to established work on extended metal surfaces, further shedding light on hot electron mechanisms and the timescales involved [ 167 ].…”