LOW-TEMPERATURE SCANNING-TUNNELING-MICROSCOPY AND SPECTROSCOPY OF THEPBSE-CL THIN-FILMS

Scanning tunneling microscope operating at 4.2 K was used for investig ation of the surface topography and local energy spectrum of the PbSe: Cl epitaxial films on BaF2 substrates. The information on the film gro wth mechanism and the surface topography was obtained. Scanning tunnel ing spectroscopy experiments at low temperatures showed the features o f the local electron density in the grains and grain boundaries. The t unneling spectra of the grains with the average size of 0.1 divided by 0.3 mu m correspond to the bulk material properties. For the first ti me the information on energy spectrum of the grain boundaries with the size around 10 nm was obtained. Their local energy spectrum differs f rom the grains' ones. The local electron density in the grain boundari es varies also from one point to other.