High-quality intrinsic ZnO film for the application of solar cell grown by ICP-assisted reactive DC magnetron sputtering at low temperature

Intrinsic zinc oxide (i-ZnO) film was prepared for CuInSe₂ (CIS) solar cell application [L. Stolt and J. Hedstrom, Appl. Phys. Lett. 62 (1993) 8; D. Rudmann, Ph.D. Thesis, University of Basel, Basel, (2004)] on glass substrate by inductively coupled plasma (ICP)-assisted DC magnetron sputtering and under a quite low temperature of 50°C. The sputtering was done in an Ar and O₂ gas mixture and a ceramic ZnO target was used. The microstructures of the film were investigated by X-ray diffractometer and scanning electron microscope. It was shown that all of the films had a c-axis preferred orientation perpendicular to the substrate. In our work, film with resistivity of 7 × 10⁸ Ω · cm and transmittance of about 80% in the visible range was prepared under the conditions of 4 mTorr working pressure and 50°C temperature.