The enhanced conductivity and stability of AZO thin films with a TiO2 buffer layer

• Published in: Physica. B, Condensed matter Vol. 407; no. 23; pp. 4518 - 4522
• Main Authors: Yang, Tianlin, Song, Shumei, Li, Yanhui, Xin, Yanqing, Du, Guiqiang, Lv, Maoshui, Han, Shenghao
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 01.12.2012; Elsevier
• Subjects: Applied sciences; Azo; AZO film; Buffer layers; Condensed matter; Electrical resistivity; Energy; Exact sciences and technology; Glass; Lime; Magnetron sputtering; Natural energy; Photovoltaic conversion; Resistivity; Solar cells. Photoelectrochemical cells; Solar energy; Stability; Thin films; TiO2 buffer layer; Titanium dioxide; Transmittance; AZO film; Stability; Transmittance; TiO2 buffer layer; Resistivity; Buffer layer; Annealing; Electrical conductivity; Doping; Absorption coefficient; Hall effect; Aluminium addition; X ray diffraction; Thin film; Solar cell; Thickness; Zinc oxide; Visible spectrum; Cathodic sputtering; TiO; Figure of merit
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/j.physb.2012.08.015

Aluminum doped zinc oxide (AZO) films were substitutes of the SnO2:F films on soda lime glass substrate in the amorphous thin-film solar cells due to good properties and low cost. In order to improve properties of AZO films, the TiO2 buffer layer had been introduced. AZO films with and without TiO2 buffer layer were deposited on soda lime glass substrates by r.f. magnetron sputtering. Subsequently, one group samples were annealed in vacuum (0.1Pa) at 500°C for 120s using the RTA system, and the influence of TiO2 thickness on the properties of AZO films had been discussed. The XRD measurement results showed that all the films had a preferentially oriented (002) peak, and the intensity of (002) peak had been enhanced for the AZO films with TiO2 buffer layer. The resistivity of TiO2 (3.0nm)/AZO double-layer film is 4.76×10−4Ωcm with the maximum figure merit of 1.92×10−2Ω−1, and the resistivity has a remarkable 28.7% decrease comparing with that of the single AZO film. The carrier scattering mechanism of TiO2 (3.0nm)/AZO double-layer film had been described by Hall measurement in different temperatures. The average transmittance of all the films exceeded 92% in the visible spectrum. Another group samples were heat treated in the quartz tube in air atmosphere, and the effect of TiO2 thickness on thermal stability of AZO films had been discussed.