Some Physical Properties of Pure and Fluorine-Doped Tin Oxide Films Used as Transparent Conducting Oxide

Abstract

For architectural use, coated window glass can be categorized into two classes: low-emissivity (E) window glass and solar control window films. Low-E glass serves a thermal insulation function. The application of low-E glass to buildings will significantly reduce energy consumption, mainly during cold seasons. Solar control films are designed to absorb or reflect incident solar radiation in order to diminish solar heat gains through glass. The application of selective coatings, i.e., low-E coating in glazings, allows for a more efficient management of heating and cooling loads of a building. Low-E coatings include many transparent conductors (TCs). TCs have a wide variety of uses. One of the applications of TCs is their use as low-emissivity windows in buildings. Another example is where the front surfaces of solar cells are covered with transparent electrodes. TCs’ ability to reflect thermal infrared heat is exploited to produce energy-conserving windows. Therefore, TCs can contribute to energy savings and can be considered important eco-materials for a sustainable energy future. This chapter includes an investigation of some of the physical properties of pure and fluorine-doped tin oxide thin films, which are TCs. Thin films were prepared on borosilicate glass slides by the spray pyrolysis technique. The optical energy gap was calculated for pure SnO₂ films. The structure of specimens was studied by the X-ray diffraction technique. The mechanical durability of doped tin oxide thin films is related to hardness. Vickers hardness and microhardness techniques were used to investigate the hardness of tin oxide thin films. We conclude that tin oxide thin films are harder than glass substrates.