HETEROJUNCTIONS AND DEVICES OF COLLOIDAL SEMICONDUCTOR-FILMS AND QUANTUM DOTS

We present an electrical characterization of thin film semiconductor d evices based on porous nanocrystalline TiO2 anatase films. It is shown that the TiO2 films can be doped, and that injecting or blocking elec trical contacts can be established by metals, semiconductors, and oxid es. This opens the way for the preparation of a number of all-solid-st ate devices. We present results on a Schottky barrier, a two-layer het erojunction on amorphous silicon, and a distributed heterojunction inv olving PbS quantum dots adsorbed on the internal surface of the TiO2 f ilm. (C) 1996 American Institute of Physics.