Ab initio calculations of surface electronic states in indium oxide

Abstract

A slab approach in the framework of ab initio calculations was applied to study surface electronic states in In 2 O 3 crystal. Density functional theory (DFT) calculations were carried out employing the WIEN 2k code and using the full potential method with Augmented Plane Waves þ local orbitals (APWþlo) formalism. Total and partial DOS (Density of States) were calculated for In and O atoms in two upper (110) surface layers. Comparison of total and partial DOS allowed determining a contribution of electronic states of different In and O surface atoms into formation of surface electronic spectra and corresponding chemical bonds. A dominant ionic character of chemical bonds in In 2 O 3 is found. Calculations were performed for three slab models with different geometry parameters. It was shown that an optimal ratio between the whole vertical size of a supercell and the vertical size of atomic cluster has to be chosen. The size of vacuum region in the slab model influences significantly on the reliability of calculated characteristics of the surface electronic structure.

Structure, stability and work functions of the low index surfaces of pure indium oxide and Sn-doped indium oxide (ITO) from density functional theory

“…Density functional theory (DFT) has become an essential tool in the atomistic characterisation of metal oxide surfaces; [21][22][23][24][25][26][27][28][29] unfortunately, surface investigations of In 2 O 3 have been limited until very recently. Fuks et al 30 studied the (110) surface using DFT; however, no energetics or surface structures were reported. Xiao et al 31 predicted ''d 0 '' magnetism on the non-stoichiometric polar (100) surface due to (unphysical) uncompensated electrical charging, but again the details of the surface structure and stability were not considered.…”

Turning Indium Oxide into a Superior Electrocatalyst: Deterministic Heteroatoms

“…The project-augmented wave (PAW) method was used to represent the core-valence electron interaction3334. To model the In 2 O 3 (110) surface, a seven-layer p (1 × 1) slab (14.406 × 10.187 Å 2 )353637383940 corresponding to 28 In 2 O 3 units cell (140 atoms) was used, in which a vacuum layer of 15 Å was applied. Because of the large size of the supercell, k-point sampling was restricted to the Γ point only.…”

Comparative Research on Cs Activation Mechanism for Al_0.5Ga_0.5As (001) and Al_0.25Ga_0.75N (0001) Surface

“…Both the AlGaAs and AlGaN samples were etched by H 2 SO 4 :H 2 O 2 :H 2 O solution with different ratios of 4:1:100 for two minutes and 2:2:1 for ten minutes due to the different etching ability. After being rinsed by deionized water and dried in air, the two photocathode samples were transferred into the ultra-high vacuum system which the base pressure was less than 3.3×10 -8 Pa and heated in vacuum at 650℃ (AlGaAs sample) and 710°C (AlGaN sample) for twenty minutes [28][29][30]. When the samples cooled to room temperature, an activation experiment was performed on high quality p-type Zn-doped AlGaAs substrate and p-type Mg-doped AlGaN substrate grown by metal organic chemical vapor deposition (MOCVD).…”