Amorphous zinc oxide thin films have been processed out of an aqueous solution applying a one step synthesis procedure. For this, zinc oxide containing crystalline water (ZnO x H(2)O) is dissolved in aqueous ammonia (NH(3)), making use of the higher solubility of ZnO x H(2)O compared with the commonly used zinc oxide. Characteristically, as-produced layers have a thickness of below 10 nm. The films have been probed in standard thin film transistor devices, using silicon dioxide as dielectric layer. Keeping the maximum process temperature at 125 degrees C, a device mobility of 0.25 cm(2)V(-1)s(-1) at an on/off ratio of 106 was demonstrated. At an annealing temperature of 300 degrees C, the performance could be optimized up to a mobility of 0.8 cm(2)V(-1)s(-1) (C) 2011 Elsevier B.V. All rights reserved.