Structural, electrical and optical characterization of semiconducting Ru2Si3

Recent band structure calculations indicate, that ruthenium silicide (Ru2Si 3) is semiconducting with a direct band gap. Electrical measurements lead t o a band gap around 0.8 eV which is technologically important for fiber com munications. This makes Ru2Si3 a promising candidate for silicon-based opti cal devices, namely LEDs. We present results on the epitaxial growth of rut henium silicide films on Si(100) and Si(111) fabricated by the template met hod, a special molecular beam epitaxy technique. We structurally characteri zed the films by Rutherford backscattering and ion channeling, X-ray diffra ction and transmission electron microscopy. To determine the electrical res istivity at high temperatures films were grown on insulating substrates to prevent parallel conduction through the substrate. Finally we show first re sults of the optical absorption performed by photothermal deflection spectr oscopy indicating pronounced absorption above 1.5 eV. (C) 2000 Elsevier Sci ence B.V. All rights reserved.