In this study the preparation of zirconia thin films with a high refractive index at low temperature is aimed for Two non-hydrolytic type approaches of wet chemical synthesis are presented Both by sol-gel and colloid chemistry highly transmissive smooth thin films of zirconia cubic and/or tetragonal crystalline phases were readily prepared after annealing at only 400 C The thin films show indices of refraction varying between 1 7 and 1 9 for annealing temperatures in the range 200-400 degrees C (C) 2010 Elsevier B V All rights reserved