Multilayered nanocoatings allow outstanding properties with broad potential for glazing applications. Here, we report on the development of a multilayer nanocoating for zinc oxide (ZnO) and antimony doped tin oxide (ATO). The combination of ZnO and ATO thin films with their promising optical properties is a cost-efficient alternative for the production of energy-efficient glazing. It is an effective modification of the building envelope to reduce current high domestic demand of electrical power for air conditioning, especially in hot climates like Saudi Arabia. In this paper, we report the development of a nanocoating based on the combination of ZnO and ATO. Principle material and film investigations were carried out on lab-scale by dip coating with chemical solution deposition (CSD), while with regard to production processes, chemical vapor deposition (CVD) processes were evaluated in a second stage of the film development. It was found that with both processes, high-quality thin films and multilayer coatings with outstanding optical properties can be prepared. While keeping the optical transmission in the visible range at around 80%, only 10% of the NIR (near infrared) and below 1% of UV (ultraviolet) light passes these coatings. However, in contrast to CSD, the CVD process allows a free combination of the multilayer film sequence, which is of high relevance for production processes. Furthermore, it can be potentially integrated in float glass production lines.
Ultrasound assisted additive free synthesis of nanocrystalline zinc oxide