Physical Properties of SnO2 Materials: II . Electrical Properties

Stannic oxide in its pure form is an n‐type wide‐bandgap semiconductor. Its electrical conduction results from the existence of point defects (native and foreign atoms) which act as donors or acceptors. Some unique properties of make the material useful for many applications. Therefore, increasing attention is being paid to studies on this oxide, especially on the methods of preparation, and its electrical and optical properties. The purpose of this series is to provide a general up‐to‐date review of the investigations carried out and to help identify important areas for further studies. The first part was concerned with the preparation and defect structure of single crystals, sintered polycrystalline samples, and thin films. In this part we review the electrical properties of these materials. The electrical properties of single crystals are well understood and the properties of sintered powder are similar to those of single crystals. However, those of films have not been explained satisfactorily up to the present time. They depend strongly on the manner of preparation and subsequent heat‐treatments in various ambients. In the third part, the optical properties of will be reviewed.