Development of the Composition Shifting Semiconductor Film by Controlling Nucleation

Abstract

Present transparent conductive films utilized for solar cells are produced mainly by using ITO (Indium tin oxide). The main component of ITO, indium is rare metal and is said to become lack in near the future. Therefore the development of the new transparent conductive film is the urgent business.

In these days, die sensitized solar cells are anticipated to become new major solar cells. Their electrode is composed with titania crystals coated on the transparent conductive film. It is said that its best manufacturing process is the wet type procedure, that is, the nucleation and crystal growth. However it is said to be difficult to develop it. I think the difficulty come from the lack of the knowledge to control its real behaviors. In this study, as the first state of the development of transparent semiconductor electrode, the nucleation process of tin oxide generated by the hydrolysis of tin chloride (IV) was investigated.

Through this study, following conclusions were obtained.

1. Larger crystals can be obtained by the calcination of the amorphous precursor than fine crystals.

2. A transparent conductive film were successfully developed by spreading and calcinating the hydrolysis product of tin chloride under high concentration and low pH conditions.