Zr (IV) doped indium oxide thin films (similar to 55 nm) were deposited onto pure silica glass by the sol-gel dip coating technique utilizing the precursors of 6 wt% equivalent oxide content. Three different Zr (IV) oxide (ZrO2) dopant concentrations (5.0, 10.0 and 15.0 wt% w.r.t. total oxides) were chosen. XRD patterns suggested the films were of distinct cubic symmetry of In2O3. Nanostructured surface feature was revealed by FESEM images. Average cluster size decreased with increasing dopant concentration as evidenced from TEM study. Blue shift of band gap and UV cut off wavelength (lambda-50) occurred with increase in dopant concentration. The refractive index gradually increased with doping. Baking atmosphere plays an important role in tailoring the refractive index (RI) of the films and relatively high RI was obtained in the case of baking in pure oxygen. Presence of both free and bound excitons was detected by the photoluminescence (PL) study. The 5 wt% doped film exhibited relatively high PL intensity at similar to 380 nm responsible for free exciton. The PL emissions gradually quenched with increase in dopant concentration. Similar behaviour was also observed when the film was baked in pure oxygen atmosphere. (C) 2009 Elsevier B.V. All rights reserved.