Electrical properties of p–n contact with oxide semiconductor thin films fabricated by liquid phase method

A p-type semiconductor, NiO, and n-type semiconductors, ZnO and TiO2, were used for making a p–n contact. These oxide semiconductor films were prepared by a liquid phase method using zinc and nickel acetates, titanium tetraisopropoixde and diethanolamine as a stabilizing agent. After coating on ITO sputtered glass substrate, the film was dried and fired at 600°C. The coating was repeated to form a stacking structure of glass/ITO (electrode)/n-type/p-type. The multilayered films using NiO, ZnO and TiO2 exhibited typical rectifying I–V characteristics. The intermediate compounds of NiTiO3 was formed between NiO and TiO2 layers and this multilayered film had a p–i–n structure after firing.