In this work transparent thin films of Ag+1-In+3 co-doped SnO2 were obtained using robotic spray pyrolysis. The effect of silver doping concentration on their optical, electrical and structural properties was investigated. Silver co-doping was varied between 0 and 12 at% in the precursor solution keeping the concentration of indium fixed at 2 at%. The optical transmittance has values between 90.3 and 82.7%, when the Ag+1 doping ranges from 0 to 12 at%. The X-ray diffraction shows a single SnO2 phase, for silver doping between 0 and 8 at%, and a new silver oxide phase when the silver increases up to 12 at%. The current-voltage characteristics show diode-like behavior for low and high doping concentrations, corresponding to 2 and 12 at%. The films exhibit photocurrent which is affected by the silver amount in the structure. The highest and most stable generated photocurrent was achieved for samples with 12 at% Ag+1 (C) 2015 Elsevier B.V. All rights reserved.