Preparation of Al-doped ZnO thin films as transparent conductive substrate in dye-sensitized solar cell

We have prepared aluminum-doped Zinc oxide (AZO) thin films on glass substrates by rf magnetron sputtering technique using ZnO ceramic target in pure argon gas with different aluminum concentrations. The bandgap of the ZnO films slightly widens with increase in Al content and the lowest sheet resistance of AZO films with Al concentration of 4.3 at.% was obtained. The effects of post-annealing treatment on structural, electrical and optical properties of the AZO thin films were investigated. Using AZO thin film with 4.3 at.% Al as the transparent substrate, a titanium dioxide based dye-sensitized solar cell was constructed and a solar to electrical energy conversion efficiency of 2.9% was achieved under AM 1.5 solar simulated sunlight.