Title: Improved luminescence properties of nanocrystalline silicon films deposited by plasma enhanced chemical vapour deposition technique at low temperature

Authors: Atif Mossad Ali, Ali Al-Hajry, M.S. Al-Assiri

Addresses: Department of Physics, Faculty of Science, King Khalid University, Abha, P.O. 9004, Saudi Arabia Department of Physics, Faculty of Science, Assiut University, Assiut 71516, Egypt. ' Department of Physics, Faculty of Science, Najran University, Najran, P.O. 1988, Saudi Arabia. ' Department of Physics, Faculty of Science, King Khalid University, Abha, P.O. 9004, Saudi Arabia

Abstract: Nanocrystalline silicon (nc-Si) films have been prepared by plasma-enhanced chemical vapour deposition (PECVD). The feed gases were SiF₄/SiH₄/H₂. The deposition temperature, T_d and the air exposure time were varied. The optical properties of the films were evaluated by measurement of the photoluminescence (PL) and the structural properties were investigated by measurements of x-ray diffraction, Fourier transform infrared absorption and Raman scattering. The structural changed from an amorphous to a nanocrystalline phase at T_d = 80°C. In addition, it suggests that T_d low condition lead to the increase in the density of SiH-related bonds and a decrease in the average grain size, <δ>. The oxygen absorption peak increases with the air exposure time. The PL intensity increases and blue shifts consistently with the decrease of <δ> and increase of oxygen content.

Keywords: nanocrystalline silicon; photoluminescence; grain size; plasma CVD; chemical vapour deposition; deposition temperature; air exposure time; nanomaterials; nanotechnology; luminescence properties.

DOI: 10.1504/IJNBM.2009.027703

International Journal of Nano and Biomaterials, 2009 Vol.2 No.1/2/3/4/5, pp.110 - 117

Published online: 08 Aug 2009 *

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