Influence of grain boundaries and interfaces on the electronic structure of polycrystalline CuO thin films
| Autor: | Wolfram Jaegermann, Hans F. Wardenga, Jan Morasch, Andreas Klein |
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| Rok vydání: | 2016 |
| Předmět: |
010302 applied physics
Materials science Band gap Doping Fermi level Analytical chemistry 02 engineering and technology Surfaces and Interfaces Sputter deposition 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials symbols.namesake Band bending 0103 physical sciences Materials Chemistry symbols Grain boundary Electrical and Electronic Engineering Thin film 0210 nano-technology Ohmic contact |
| Zdroj: | physica status solidi (a). 213:1615-1624 |
| ISSN: | 1862-6300 |
| Popis: | CuO thin films were grown by reactive magnetron sputtering and analyzed with respect to their structural, chemical, optical, and electrical properties. The films are strongly p-type with carrier concentrations of ∼ 1020 cm−3. Carrier accumulation at grain boundaries is evident from temperature and gas phase dependent conductivity measurements. The films show high absorption coefficients with a band gap of approximately 1.5 eV. Interface formation with TiO2 and Au was studied by photoelectron spectroscopy. Regarding the TiO2/CuO interface, a strong band bending in the TiO2 substrate and a valence band offset of ∼ 2.4 eV were observed. The TiO2 conduction band is therefore approximately midgap of CuO at the interface. CuO is chemically reduced upon Au deposition but an ideal ohmic contact is formed with a Fermi level at the valence band maximum of CuO. Solar cell device structures were prepared of fluorine doped SnO2/TiO2 substrates and Au back contacts, revealing open circuit voltages of |
| Databáze: | OpenAIRE |
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