Preparation and properties of Si/SnO2 heterojunctions

A combined spray-CVD method is discussed by which SnO2 films can be prepared reproducibly using the high-temperature hydrolysis reaction of SnCl4. Homogeneous films of good conductivity were obtained when the reaction mixture SnCl4/H2O contained only 50 percent or less of the stoichiometric amount of water. Heterojunctions were produced by depositing the films on Si single crystals. For these devices the dependence of the photocurrent-voltage curve on the conductivity of the SnO2 was analyzed.