Transparent Electrical Conductive In-Sn Oxide Films

Transparent electrical conductive films, recently, have been studied for wide applications in electrooptic devices such as display panels and solar sell, etc. The purpose of this investigation is to research the Sn-doped indium oxide films with low electrical resistivity, high visible transmission by chemical spray deposition method. The film was deposited on pyrex, quarz, and soda-lime glass plate to find the optimum substrate temperature and Sn concentration. For the spray solution, InCl_3-SnCl_4 combination was adopted. These films were deposited on the substrate in a temperature ranging from 400℃ to 900℃, then, the optimum substrate temperature was found to be in the range of 500℃-700℃, and optimum concentration of Sn being in the range of 1 at.%-17at.% Under these temperature conditions, electrical sheet resistance as low as 70 ohm/square of the film has been obtained using Sn, 1 at.% spray solution, and that of 100 ohm/square obtained using 9 at.% solution. The optical transmission of these films was about 90% in the visible and near-infrared range. The decrease in electrical sheet resistance of these films was 40% by heat treatment in O_2 atmosphere at 200℃ for 30-120 minutes, but the decrease was not observed on the optical transmission. It was found by X-ray diffraction method that these films were composed of indium oxide without crystallized tin oxide.