Indium zinc tin oxide (IZTO) thin films were deposited on glass substrate by radio frequency magnetron sputtering at various substrate temperatures. The indium content of the IZTO targets was reduced from 60 at.% to 30 at.% and replaced with equal amounts of zinc and tin (20, 25, 30, and 35 at.%). The crystallinity of the as-deposited films improved with increasing substrate temperature. For all IZTO films, the onset of crystallization began at above 100 degrees C. The IZTO films deposited at higher substrate temperature showed better optical transmittance and lower electrical resistivity than those deposited at lower temperatures. The minimum electrical resistivity of approximately 8.0 Chi 10(-4) Omega.cm was observed in the IZTO films prepared deposited at 400 degrees C from targets containing 20 at.% Zn and 20 at.% Sn. The optical transmittance was above 80% for all IZTO films. On the other hand, higher co-doping resulted in amorphous films, which slightly impaired the electrical properties. The deterioration in the electrical properties of IZTO films, however, was compensated for by the higher optical transparency. Therefore, reduced-indium IZTO films are promising alternatives for some transparent conducting oxide applications. (C) 2014 Elsevier B.V. All rights reserved.