The contribution of the amorphous phase in nanocrystalline thin films of germanium and gallium arsenide

The nanoscale semiconductor structures obtained by evaporation in high vacuum at different temperatures show anomalous high photoconductivity. This may be connected with the structure of clusters which can consist of both crystalline and amorphous phases. We propose a method of extracting amorphous and crystalline contributions to the clusters. This method is based on the extraction of corresponding contributions to the extended x‐ray absorption fine structure (EXAFS) spectra. The method of EXAFS spectroscopy allows information to be obtained about the local atomic structure of materials in different states, including gases and liquids. The macro‐structure of films was examined by different methods, i.e. x‐ray diffraction, transmission electron microscopy (TEM), and atomic force microscopy (AFM). We obtained the volume portion of the amorphous phase to the nanosized particles of Ge as about 70% and for GaAs about 50%. Copyright © 2004 John Wiley & Sons, Ltd.