Model dielectric function analysis of the critical point features of silicon nanocrystal films in a broad parameter range
Emil Agocs1,2 , Androula G. Nassiopoulou3, Silvia Milita4, and Peter Petrik2
1 Doctoral School of Molecular- and Nanotechnologies, Faculty of Information Technology, University of Pannonia, Egyetem u.10, Veszprém, H-8200, Hungary
2Research Institute for Technical Physics and Material Science (MFA), Research Centre for Natural Sciences, H-1525 Budapest, POB 49, Hungary
3 IMEL/NCSR Demokritos, Aghia Paraskevi, 153 10 Athens, Greece
4 CNR-IMM Sezione Bologna, Via Gobetti, 40129 Bologna, Italy 2013
Abstract
Due to quantum-confinement the band structure of silicon nanocrystals (NCs) is different from that of bulk silicon and strongly depends on the NC size. The samples we investigated have been prepared using chemical vapor deposition and annealing allowing a good control of the parameters in terms of both thickness and NC size, being suitable as model systems. The problem of the analysis is that the critical point features of the dielectric function can only be described with acceptable accuracy when using numerous parameters. The majority of the fit parameters are that describing the oscillators of different line-shapes. In this work we show how the number of fit parameters can be reduced by a systematic analysis to find non-sensitive and correlating parameters to fix and couple as much parameters as possible.
