Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10633698 | Optical Materials | 2005 | 6 Pages |
Abstract
In this study we report results on a series of Si/SiO2 multilayers periods deposited by standard CMOS processes on thermally oxidised Si substrates. Each period was formed by alternating a low-pressure chemical vapour deposition (LPCVD) nanocrystalline silicon thin film and a SiO2 thin film obtained by atmospheric pressure chemical vapour deposition (APCVD). High-resolution TEM (HRTEM) and Raman spectroscopy have been used for the physical characterisation of the nc-Si/SiO2 multilayers. The HRTEM analysis revealed a columnar structure, with an average grain size of 15Â nm for the silicon layers. The Si-SiO2 interfaces were smooth with a surface roughness for silicon layers less than 1Â nm, as estimated from HRTEM analysis. Raman measurements demonstrate that the nanocrystalline silicon (nc-Si) layers are free-of-stress. Room temperature photoluminescence (PL) spectra, obtained by using a 325Â nm continuous wave (CW) laser excitation, showed a broad blue peak centred on 440Â nm. The intensity of the blue PL band increased with the number of periods in the nc-Si/SiO2 multilayers. The origin of this intense room temperature blue PL band is discussed.
Related Topics
Physical Sciences and Engineering
Materials Science
Ceramics and Composites
Authors
M. Modreanu, E. Aperathitis, M. Androulidaki, M. Audier, O. Chaix-Pluchery,