First-principles density functional theory (DFT) is employed to study the electronic structure of oxygen and gallium vacancies in monoclinic bulk β-Ga2O3 crystals. Hybrid exchange–correlation functional B3LYP within the density functional theory and supercell approach were successfully used to simulate isolated point defects in β-Ga2O3. Based on the results of our calculations, we predict that an oxygen vacancy in β-Ga2O3 is a deep donor defect which cannot be an effective source of electrons and, thus, is not responsible for n-type conductivity in β-Ga2O3. On the other hand, all types of charge states of gallium vacancies are sufficiently deep acceptors with transition levels more than 1.5 eV above the valence band of the crystal. Due to high formation energy of above 10 eV, they cannot be considered as a source of p-type conductivity in β-Ga2O3.

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The synthesis of CdTe nanocrystals (NCs) is performed by electrochemical deposition into prepared ion tracks in a a‐SiO2/Si‐n template. As a result, CdTe NCs are obtained in a wurtzite (WZ) crystal phase. The measurement of the current–voltage characteristics shows that the CdTe (WZ NC)/SiO2/Si system obtained in this way has n‐type conductivity. Computer simulations using the CRYSTAL computer code show good agreement between experimental and calculated lattice parameters. The theoretical calculations also show that the crystal has a direct bandgap at the Γ point of the Brillouin zone.

This paper presents a study of nanoclusters obtained by electrochemical deposition (ECD) of zinc in the a‐SiO2/Si‐n track template. The nanoporous SiO2 layer on Si substrate (track template) has been created by irradiation with swift Xe ions and further etching in HF solution. The morphology of SiO2/Si‐n track templates and precipitated Zn‐based clusters are examined using a scanning electron microscope JSM 7500F. The crystallographic structure of the Zn‐based precipitates was investigated by means of X‐ray diffraction (XRD). X‐ray analysis is carried out on a D8 ADVANCE ECO X‐ray diffractometer. The Bruker AXSDIFFRAC.EVAv.4.2 software and the international ICDD PDF‐2 database are used to identify the phases and study the crystal structure. From XRD data, it has been found the formation of three crystalline phases of zinc oxide nanocrystals electro‐deposited into SiO2/Si track template: wurtzite, sphalerite, and rock salt structures. Wurtzite is obtained on an amorphous surface of silicon dioxide. Possible mechanisms of ZnO formation instead of metal Zn nanocrystals are discussed.

Hydrogen atoms unavoidably presented in ZnO samples or thin films during their synthesis considerably affect electrical conductivity. Results of first principles hybrid functional linear combination of atomic orbitals calculations are discussed for hydrogen atoms incorporated in bulk or adsorbed upon non-polar ZnO surfaces. The energy of H incorporation, atomic relaxation, electronic density redistribution and modification of the electronic structure are compared for both surface adsorption and bulk absorption. It is shown that hydrogen forms a strong bonding with the surface O ions (Eads = 2.7 eV) whereas its incorporation into bulk is energetically quite unfavorable. Hydrogen adsorption reduces the surface energy. Surface hydrogen atoms are very shallow donors, thus contributing to the electronic conductivity and ZnO metallization.