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Title:A study of the molecular behavior in the vibronic and excitonic properties of silicon nanoparticles
Author(s):Rao, Satish Kodali
Doctoral Committee Chair(s):Nayfeh, Munir H.
Department / Program:Physics
Subject(s):silicon nanoparticles
electrochemical etching
Raman Spectroscopy
General Atomic Molecular Electronic Structure System (GAMESS) Copmutation
Abstract:The molecular behavior of silicon nanoparticles, produced via electrochemical etching of a bulk precursor, is studied. The smallest particle, 1 nrn in diameter, is amenable to first principles modeling due to the manageable number of atoms in the structure. The ability to produce these particles in macroscopic amounts allows for the testing of these models through various optical techniques. Raman spectroscopy measurements, performed on 1 nrn silicon nanoparticles suspended in liquid, were found to agree well with vibrational modes calculated using Hartree-Fock theory through the GAMESS package. The Raman peaks offer direct evidence of stretched Si-Si surface dimers in the reconstructed particle, which have been suggested to be the source of its optical activity. The peak positions and FWHM's, along with calculations of the normal modes, suggest that the nanoparticle exhibits strong molecular behavior despite its derivation from a bulk structure. Low temperature PL measurements show the involvement of the dimers in the luminescence characteristics.
Issue Date:2006
Genre:Dissertation / Thesis
Other Identifier(s):5513593
Rights Information:©2006 Rao
Date Available in IDEALS:2012-06-07

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