Characterization of the interface between highly conductive Ga:ZnO films and the silicon substrate
| Autor: | Fernando Agulló-Rueda, S. Palanco, Pilar Herrero, Elena Navarrete-Astorga, Mercedes Gabás, Efraín Ochoa-Martínez, J.J. Martínez-Serrano, José R. Ramos-Barrado, Angel R. Landa-Cánovas |
|---|---|
| Přispěvatelé: | European Commission, Junta de Andalucía, Ministerio de Economía y Competitividad (España) |
| Rok vydání: | 2017 |
| Předmět: |
Materials science
Silicon Band gap Ga doping Analytical chemistry General Physics and Astronomy chemistry.chemical_element 02 engineering and technology Substrate (electronics) 010402 general chemistry 01 natural sciences X-ray photoelectron spectroscopy Thin film Doping Surfaces and Interfaces General Chemistry Interface Sputter deposition 021001 nanoscience & nanotechnology Condensed Matter Physics 0104 chemical sciences Surfaces Coatings and Films Dielectric spectroscopy TCO chemistry ZnO 0210 nano-technology |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname |
| ISSN: | 0169-4332 |
| DOI: | 10.1016/j.apsusc.2017.05.072 |
| Popis: | Gallium-doped zinc oxide films are an interesting alternative for transparent conductive materials. To improve their performance, the interface between the grown layer and the substrate must be fully understood. Accordingly, ZnO and Ga:ZnO films have been deposited onto p-type doped Si (111) substrates by magnetron sputtering for 1, 2, 3 and 20 min and their interfaces characterized by transmission electron microscopy, photoelectron spectroscopy, spectroscopic ellipsometry and impedance spectroscopy. The combination of transmission electron microscopy techniques suggested a more complex interface chemistry in the Ga:ZnO/Si case, a point confirmed by x-ray photoelectron spectroscopy measurements on very thin films. While the ZnO/Si interface consists mostly of silicon oxides, zinc silicates and some Zn0, the Ga:ZnO/Si interface, besides these constituents, has a noticeable amount of Ga:ZnO and small quantities of Ga0. The band alignment deduced from the photoelectron spectroscopy measurements, together with the layers and Si band gap values, evidences a higher work function for the doped film and a smaller conduction band barrier for the Ga:ZnO/Si interface. Concerning the optical and electrical characteristics, spectroscopic ellipsometry revealed no significant differences between the two interfaces, while impedance spectroscopy measurements demonstrated that the Ga:ZnO/Si interface is less resistive than the ZnO/Si one. Authors gratefully acknowledge financial support from the Spanish Ministerio de Economía & Competitividad (MINECO) and E.U. FEDER funds through the projects FUNCOAT-CSD2008-00023-CONSOLIDER INGENIO, TEC2014-53906-R, TEC2014-54260-C3-3-P, RYC-2010-06711 and MAT2014-57547-R, and from the Junta de Andalucía (FQM-192). |
| Databáze: | OpenAIRE |
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