Structural and optical properties of calciumdoped zinc oxide sputtered from nanopowder target materials

Calcium-doped zinc oxide (ZnO:Ca) thin films were deposited onto glass substrates by rf-magnetron sputtering at ambient temperature using nanocrystalline powder synthesized by the sol-gel method. The structural, electrical and optical properties of films as a function of Ca concentration were investigated. Ca-doped films exhibit high optical transparency in the visible and near infrared region. A minimum resistivity of 2.3*10^-3 Ωcm, was obtained for the film doped with 3.0 at.% of calcium. Due to their good optical and electrical properties, ZnO:Ca films are promising candidates for their use as transparent electrodes in solar cells.