The texture formation on the surface of SnO2:F films was carried out using a four component CVD reaction system with tin tetrachloride as a main source. The texture up to about 30% in terms of the haze value could be formed by selecting CVD parameters. It was found in the transmission measurement of hazy SnO2:F films that a part of incident light escaped from the cut edges of the glass substrate even if the integration sphere was used. A nondestructive immersion method is proposed. This enables more exact evaluation of light quantity effectively transmitted to the active part of the a-Si solar cell when it is combined with the reflectance measurement of a pseudocell. It was also found that the reflectance of pseudocells decreased as the haze value increased, and as the shape of grains became sharper when the haze values were similar.

Multilayer coatings consisting of thin silver layers sandwiched between layers of transparent conducting metal oxides were investigated from the view-point of low-resistance electrodes for use in flat panel displays. Optimization of the multilayer coatings resulted in a five-layer coating composed of indium and zinc oxide composite material (IZO) and silver containing 1 wt% of palladium (Ag–Pd). The coatings had satisfactory properties of low resistance, high transmittance, high moisture and alkali resistance, and good patterning.

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Silver-based multilayer coatings are well known to be transparent films with low electrical resistivity. In particular, indium and zinc composite oxide (IZO)/silver containing palladium (AgPd) multilayer coatings have good pattering properties and durability. However, the IZO/AgPd multilayer coatings do not have sufficient alkali durability as transparent electrodes of flat panel displays (FPDs). In order to solve this problem, coatings covered with a protective layer of tin-doped indium oxide (ITO) were investigated. Over-coating of an ITO layer degraded the patterning properties of the multilayer coatings because the etching rates of ITO, IZO and AgPd layer were very different. From the viewpoint of controlling the etching rate of each layer independently, the etching solution composed of hydrobromic acid and iron chloride was adjusted, so that the ITO/IZO/AgPd/IZO/AgPd/IZO/substrate multilayer coatings could be fabricated into fine patterns for electrodes. The multilayer coatings thus prepared are more tolerable for alkali detergents used in the production process of FPDs.

Hydrogen plasma treatment of textured Sn0,:F TCO (transparent conductive oxide) films coated with ZnO layer of lOOA in thickness was investigated for high efficiency a-Si solar cells. It was found that ZnO over-layered structure was effective to improve the hydrogen plasma durability. Furthermore, it was shown that the resistivity of over-layered "CO films decreased dramatically after the hydrogen plasma treatment at a temperature of 300°C without any change in optical transmission. The decrease in resistivity was due to the sufficient increase in Hall mobility, which was caused by the elimination of chemical reduction. After the hydrogen plasma treatment under the optimized condition, the highest Hall mobility of 70 cm2/V.sec, sheet resistance below 5 n l s q . and optical transmission above 85% were attained.