Experimental Determination of Optical and Structural Properties of Nanostructured SRO films Deposited by HFCVD and Theoretical Predictions By Global Reactions Model and DFT Method

N.D. Espinosa–Torres; A.D. Hernandez de la Luz; J.F.J. Flores–Gracia; J.A. Luna–Lopez; J. MartÃƒÂ­nez–Juarez; D.E. Vazquez–Valerdi; A. Benitez–Lara

Volume : IV, Issue : X, October - 2014

Experimental Determination of Optical and Structural Properties of Nanostructured SRO films Deposited by HFCVD and Theoretical Predictions By Global Reactions Model and DFT Method

N. D. Espinosa Torres, A. D. Hernandez De La Luz, J. F. J. Flores Gracia, J. A. Luna Lopez, J. Mart Nez Juarez, D. E. Vazquez Valerdi, A. Benitez Lara

Abstract :

This current work is devoted to present some important results obtained by theoreticalcal&ndash;culations using DFTmethod and the Global Reactions Model (GRM)in relation to molecular structures and optical properties such as photoluminescence (PL),Fourier Transform Infrared (FTIR)spectroscopy and energy gaps Egfor silicon nanoclusters (Sin ch &nbsp;) em&ndash;bedded in silicon rich oxide (SRO) films. We make comparisons between theoretical predictions and experimental results taking as reference experimental results obtained from measurements performed on SRO thin films obtained by the Hot Filament Chemical Vapor Deposition (HFCDV) technique. We stress that the scope of our theoretical predictions is general since it does not depend on the particular technique used to obtain the SRO struc&ndash;ture but rather the suggested Sin on &nbsp;structure used in our GRM. As for main results found we have that a good correlation exists for Eg values in the case of films grown at 10200C corresponding to Si8 c8 &nbsp;and Si8 c16 molecular structures suggested as well as for Siox &nbsp;films grown at 11500C in such case a molecular structuretype Si9 c9 &nbsp;is associated. Regards PL correlation, Siox &nbsp;film grownat 9000C gives a PL spectrum with two main peaks at 440nm and 548nm while theoretical spectrum shows peaks at 471nm and around of 549.8 nm and the corresponding molecular structure is type Si16c16. Besides, the same sample with a further annealingdisplays luminescencepeaked at 405nm, 749nm and 820nm and in this case theoretical results predict only one correlated peak at 415nm using a molecule type Si6 c6 .Also, in relation to the FTIR correlation, theoretical calculations predict frequencies of viational modes ofbonds (rocking,bending,stretching) and (wagging, bending) whose valuesare well located in the experimental frequency range and the corresponding atomic structure is type Si16o16 .