Substrate temperature effect on the nanoscale multilayer ZnS/Ag/ZnS for heat mirror application

Nanoscale multilayers of ZnS/Ag/ZnS were deposited on Corning glass substrates at different substrate temperatures. The depositions were carried out in high vacuum using electron beam deposition technique at 20, 60, 100 and 150 °C, respectively. The optical and electrical performance of each single layer and the accomplished ZnS/Ag/ZnS multilayer system were characterized using spectroscopic ellipsometry analysis, XRD and finally AFM. Based on these analyses and associated theories, such as the characteristic matrix theory, the optimized multilayer system was speculated and tested. Crystallographic structures of the films were studied by X-ray diffraction. In addition to X-ray diffraction, morphological characterizations were carried out by AFM in order to observe the deposited particle size, packing and roughness of the films. The optimum performance was achieved at the substrate temperature of 60 °C.