The effectiveness of low-emissivity coating on a polymer film
This work describes the effectiveness of low-emissivity (low-E) coating on the polymer film with TiO2/ZnO:Ga/Ag/ZnO:Ga/TiO2 structure and the results of heat monitoring. The characteristics of the coating which determine the reduction of heat loss by the low-E coating are given. Also the results of efficiency calculations for low-E coating are presented, such as resistance to heat transfer, heat savings when installing low-E coating on the polymer film, etc. The heat monitoring is carried out to determine the effectiveness of low-E coating. The results of heat monitoring illustrate the effectiveness of low-E coating.
The base layer effect on the d.c. conductivity and structure of direct current magnetron sputtered thin films of silver
Abstract Many low-emissivity solar-control optical coatings on glass consist of a repeating dielectric–silver–dielectric thin film period. We have investigated the effect of structure of the dielectric base layer on the conductivity, structure, and thermal stability of contiguous silver films up to 500 A thick. All individual layers were deposited by d.c.-magnetron cathode sputtering. Specifically, a detailed comparison of thin films of amorphous zinc stannate with crystalline zinc oxide showed that the latter improves the conductivity of 50–100 A and thicker silver layers. X-Ray diffraction analysis showed that zinc oxide with a preferred basal plane orientation results in the preferred growth of the Ag(111) planes parallel to the float glass substrate. Transmission electron microscopy results support the above observation. The transmission electron microscopy results also indicate that the silver–dielectric interface is of similar quality in both cases, thus eliminating the role of the interface as a major cause of the above difference. Our data on the structure and electrical properties of heat-treated samples suggest that the preferential growth of the silver layer results in its higher thermal stability.
Hillock formation, hole growth and agglomeration in thin silver films
Abstract Thin silver films deposited onto quartz substrates by cathodic sputtering showed hillock growth on annealing in vacuum and in atmospheres of oxygen, helium and argon. Further heating in an oxygen atmosphere caused hole growth and finally led to agglomeration in the films, whereas no hole formation or agglomeration was observed on annealing the films in vacuum and in helium or argon atmospheres. The phenomenon of hillock formation observed in the present case has been explained on the basis of thermal stress relaxation occuring by diffusion creep, with the additional effect of the high surface diffusion of silver atoms on an oxygen-covered silver surface. The hole growth observed as a result of annealing in an oxygen atmosphere could be suitably explained by surface diffusion of silver atoms while the agglomeration occurs during the process of achieving a minimum energy configuration.