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Journal of Nanotechnology
Volume 2011 (2011), Article ID 242398, 10 pages
Research Article

Hydrogenated Nanocrystalline Silicon Thin Films Prepared by Hot-Wire Method with Varied Process Pressure

1School of Energy Studies, University of Pune, Pune 411 007, India
2Center for Materials for Electronics Technology (C-MET), Panchawati, Pune 411 008, India
3UGC-DAE CSR, University Campus, Khandwa Road, Indore 452 017, India
4Department of Physics, University of Pune, Pune 411 007, India

Received 15 March 2011; Revised 16 April 2011; Accepted 6 May 2011

Academic Editor: Yoke Khin Yap

Copyright © 2011 V. S. Waman et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Hydrogenated nanocrystalline silicon films were prepared by hot-wire method at low substrate temperature (200C) without hydrogen dilution of silane (SiH4). A variety of techniques, including Raman spectroscopy, low angle X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, atomic force microscopy (AFM), and UV-visible (UV-Vis) spectroscopy, were used to characterize these films for structural and optical properties. Films are grown at reasonably high deposition rates (>15 Å/s), which are very much appreciated for the fabrication of cost effective devices. Different crystalline fractions (from 2.5% to 63%) and crystallite size (3.6–6.0 nm) can be achieved by controlling the process pressure. It is observed that with increase in process pressure, the hydrogen bonding in the films shifts from Si–H to Si–H2 and complexes. The band gaps of the films are found in the range 1.83–2.11 eV, whereas the hydrogen content remains <9 at.% over the entire range of process pressure studied. The ease of depositing films with tunable band gap is useful for fabrication of tandem solar cells. A correlation between structural and optical properties has been found and discussed in detail.