In this work, a study of the molecular adsorption and geometry of phenol on the nonpolar (101̅0) ZnO surface has been carried out. In an attempt to reproduce a more realistic system, an oxygen vacancy has been introduced in the surface, which leads to an increase in the band gap, from 1.16 eV for the pristine surface to 1.38 eV in the defective one, and a local level within the band gap, which corresponds to an F-center type. Calculations performed after the introduction of a phenol molecule in different configurations over the surface suggest that dissociative chemisorption is the main phenomena, with two interesting scenarios: first, the charge can be transferred from the molecule toward the surface, and vice versa, depending on the adsorption site.

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We propose an explanation for the origin of n-type electrical conductivity in SnO2 based on the results obtained from the DFT+U simulations. Two competitive intrinsic point defects, namely oxygen vacancy and hydrogen impurity, have been considered at different positions within the crystalline lattice in order to find out the equilibrium configurations and to analyze corresponding density of states (DOS) patterns along with the electron localization function (ELF). It has been demonstrated that hydrogen could be solely responsible for the n-type conductivity whereas the oxygen vacancy appears to have not a notable influence upon it. The computational analysis is backed up by some experimental data for undoped tin dioxide.