The surface of "unprotected" nanoscale platinum clusters (1～3nm) were modified with PPh~3, and the obtained PPh~3-Pt nanoclusters were extracted into toluene. The resulted colloidal dispersion of the PPh~3-Pt nanoclusters can spontaneously form homogeneous, optical transmissive thin films on the surface of glass under air. After heated under air at 400℃, the platinum nanocluster thin films were transformed to optical transmissive, electrically conductive platinum oxide semiconductor thin films. The film formation process was followed by UV-vis spectra measurements. The morphological structure of the films was characterized by using SEM and TEM. The relationship between the electrical conductivity of the thin films and the conditions for the film treatments was studied. Changes in the components of the thin films treated under different conditions were studied by using XPS. It has been revealed that oxygen dissolved in the colloidal solution takes an important role in the film formation process of the PPh~3-Pt nanoclusters.

Key words: PLATINUM OXIDE, SEMICONDUCTOR, THIN FILMS, PLATINUM, COLLOID, SCANNING ELECTRON MICROSCOPES, TRANSMISSION ELECTRON MICROSCOPY