Copper-Zinc Oxide Synergistic Approach as Low-Emissivity Material for Energy-Saving Windows

Abstract

In luxurious glass buildings and constructions, heat gain (or heat loss) mostly comes through the windows. Infrared (IR) radiation is an important factor that causes the entry of heat into the buildings. To save energy consumption of air conditioners, low-emissivity (Low-E) glass coating applications are focused. In the energy-saving field, transparent conductive oxide (TCOs) are used as coatings to minimized IR entry. In this work, copper-doped zinc oxide (CZO) is synthesized for thermal reflective material. Cu(II) ions are doped to ZnO by a sol-gel method to obtain CZO nanoparticles and is coated on a glass substrate. The morphology of CZO is investigated with scanning electron microscopy (SEM); phase crystallinity is determined by X-ray diffraction (XRD); and UV-Vis-NIR spectroscopy is used to characterize UV/IR-shielding and also the optical transparency. IR cameras and in-lab thermal insulation setup are used to test the heat insulation properties. The result shows that 15% copper-doped zinc oxide has the best insulation from IR rays with the lowest temperature in the interior (T3) of 50.6°C while the outer temperature (T2) was at 85.5°C the lowering of the temperature by 34.9°C (cooler by 59%). CZO synthesized from the sol-gel method has promising properties for Low-E glass coating applications.