In order to increase the performance of a solar-thermal flat-plate collector, we insert a double glazing with low-emitting (low-e) coating on the inner glass pane. The low-e coating system is based on sputter deposited aluminum-doped zinc oxide (AZO) and additional antireflective (AR) coatings. In this paper, we analyze the optical and electronic AZO film properties in dependence of the process parameters such as substrate temperature, argon pressure, direct current (DC) power, and target doping concentration. Emphasis is placed on the influence of these coating properties and the application of AR coatings on the efficiency of the double-glazed collector. Simulations of the collector efficiency with our collector model are presented. (C) 2012 Elsevier B.V. All rights reserved.