Chapters authored
Theoretical and Experimental Characterization of Silicon Nanoclusters Embedded in Silicon-Rich Oxide films
We present theoretical calculations using DFT method and the Global Reaction Model (GRM) for molecular structures and photoluminescence (PL) and Fourier Transform Infrared (FTIR) spectroscopy for silicon nanoclusters (Si-NCs) embedded in silicon rich oxide (SRO) films. Correlations between theoretical predictions and experimental results are made taking as reference experimental results obtained from measurements performed on SRO thin films obtained by the Hot Filament Chemical Vapor Deposition (HFCVD) technique. Our theoretical predictions are general since they do not depend on the particular technique used to obtain such films but rather the suggested SinOn structures. A good correlation exists for Eg values for films grown at 1300°C corresponding to Si8O8 and Si16O16 molecular structures suggested and for films grown at 1150°C with Si9O9. Regards PL correlation, a film grown at 900°C gives a spectrum peaked at 440nm and 548nm while theoretical one shows peaks at 471nm and 549.8 nm for a structure Si16O16. Such sample with a further annealing displays peaks at 405nm, 749nm and 820nm with theoretical predictions at 415nm using Si6O6. As for FTIR, theoretical calculations predict vibrational mode frequencies of bonds Si-O and Si-H whose values are well located in the experimental frequency range corresponding to the structure Si16O16.
Part of the book: New Research on Silicon