{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/31394"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/31394","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"A study of the molecular behavior in the vibronic and excitonic properties of silicon nanoparticles","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.","abstract_html":"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.","abstract_has_math":false,"creators":["Rao, Satish Kodali"],"institution":null,"degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Physics","degree_department":null,"school":null,"contributors":["Nayfeh, Munir H."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2012,"date_issued":"2012-06-07T20:36:06Z","date_published":"2012-06-07T20:36:06Z","updated_at":"2026-07-22T22:25:30Z","subjects":["silicon nanoparticles","electrochemical etching","Raman Spectroscopy","General Atomic Molecular Electronic Structure System (GAMESS) Copmutation"],"languages":["en"],"rights":["©2006 Rao"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["5513593"],"render_values":[{"text":"5513593","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/31394","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Nayfeh, Munir H."]},{"key":"dc:creator","label":"Author","values":["Rao, Satish Kodali"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2012-06-07T20:36:06Z","10000-01-01","2006"]},{"key":"dc:type","label":"Dc Type","values":["Dissertation / Thesis","text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Physics"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["silicon nanoparticles","electrochemical etching","Raman Spectroscopy","General Atomic Molecular Electronic Structure System (GAMESS) Copmutation"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["©2006 Rao"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/31394","5513593"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["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.","Submitted by William Weathers (weathrs2@illinois.edu) on 2012-06-07T20:36:06Z No. of bitstreams: 1 2006_rao.pdf: 3974850 bytes, checksum: c1fb2a83082e75a13e1417249ce2c71d (MD5)","Made available in DSpace on 2012-06-07T20:36:06Z (GMT). No. of bitstreams: 1 2006_rao.pdf: 3974850 bytes, checksum: c1fb2a83082e75a13e1417249ce2c71d (MD5) Previous issue date: 2006","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by William Weathers (weathrs2@illinois.edu) on 2012-06-07T20:36:06Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:10:35-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: Thesis","Thesis","U of I Only"]},{"key":"dc:title","label":"Title","values":["A study of the molecular behavior in the vibronic and excitonic properties of silicon nanoparticles"]}]}],"canonical_facts":{"dc:contributor":["Nayfeh, Munir H."],"dc:creator":["Rao, Satish Kodali"],"dc:date":["2012-06-07T20:36:06Z","10000-01-01","2006"],"dc:description":["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.","Submitted by William Weathers (weathrs2@illinois.edu) on 2012-06-07T20:36:06Z No. of bitstreams: 1 2006_rao.pdf: 3974850 bytes, checksum: c1fb2a83082e75a13e1417249ce2c71d (MD5)","Made available in DSpace on 2012-06-07T20:36:06Z (GMT). No. of bitstreams: 1 2006_rao.pdf: 3974850 bytes, checksum: c1fb2a83082e75a13e1417249ce2c71d (MD5) Previous issue date: 2006","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by William Weathers (weathrs2@illinois.edu) on 2012-06-07T20:36:06Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:10:35-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: Thesis","Thesis","U of I Only"],"dc:identifier":["http://hdl.handle.net/2142/31394","5513593"],"dc:language":["en"],"dc:rights":["©2006 Rao"],"dc:subject":["silicon nanoparticles","electrochemical etching","Raman Spectroscopy","General Atomic Molecular Electronic Structure System (GAMESS) Copmutation"],"dc:title":["A study of the molecular behavior in the vibronic and excitonic properties of silicon nanoparticles"],"dc:type":["Dissertation / Thesis","text"],"thesis:degree_discipline":["Physics"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."]},"updated_at":"2026-07-22T22:25:30Z"}