{"id":{"repo_id":"missouri","oai_identifier":"oai:mospace.umsystem.edu:10355/33098"},"canonical_url":"https://search.dev.ndltd.org/etd/missouri/oai:mospace.umsystem.edu:10355/33098","repository":{"repo_id":"missouri","name":"University of Missouri","base_url":"https://mospace.umsystem.edu/oai/request"},"display":{"title":"High pressure spectroscopic studies of organic device materials","abstract":"A comparison of photoluminescence spectra of as-is and thermally cycled di-octyl substituted polyfluorene (PF8) under pressure has been used to disentangle inter- and intra-chain interactions. Raman study of this system shows a strong electron-phonon interaction between the Raman phonon and the electronic continuum. Photoluminescence and phosphorescence studies of a ladder type poly(para-phenylene) (PhLPPP) under pressure have given for the first time an evidence that the singlet-triplet splitting remains almost a constant under enhanced intermolecular interaction. For polymer bulkheterojunctions of P3HT or PhLPPP with PCBM, the photoluminescence and absorption spectra reveal that the LUMO band-edge off-set increases with pressure. Raman studies under pressure show that the molecular ordering is barely affected by pressure in the pristine P3HT, whereas the ordering decreases with pressure in PCBM blended P3HT beyond 3.0 GPa.","abstract_html":"A comparison of photoluminescence spectra of as-is and thermally cycled di-octyl substituted polyfluorene (PF8) under pressure has been used to disentangle inter- and intra-chain interactions. Raman study of this system shows a strong electron-phonon interaction between the Raman phonon and the electronic continuum. Photoluminescence and phosphorescence studies of a ladder type poly(para-phenylene) (PhLPPP) under pressure have given for the first time an evidence that the singlet-triplet splitting remains almost a constant under enhanced intermolecular interaction. For polymer bulkheterojunctions of P3HT or PhLPPP with PCBM, the photoluminescence and absorption spectra reveal that the LUMO band-edge off-set increases with pressure. Raman studies under pressure show that the molecular ordering is barely affected by pressure in the pristine P3HT, whereas the ordering decreases with pressure in PCBM blended P3HT beyond 3.0 GPa.","abstract_has_math":false,"creators":["Paudel, Keshab Raj, 1973-"],"institution":"University of Missouri--Columbia","degree_name":"Ph. D.","degree_level":"Doctoral","degree_discipline":"Physics and astronomy (MU)","degree_department":null,"school":null,"contributors":[],"advisors":["Chandrasekhar, Meera","Guha, Suchi"],"committee_chairs":[],"committee_members":[],"year":2012,"date_issued":"2012","date_published":"2012","updated_at":"2026-07-24T03:07:35Z","subjects":["singlet-triplet splitting","di-octyl substituted polyfluorene","Raman phonon","electronic continuum"],"languages":["eng","English"],"rights":["OpenAccess."],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier.doi","label":"DOI","values":["https://doi.org/10.32469/10355/33098"],"render_values":[{"text":"https://doi.org/10.32469/10355/33098","href":"https://doi.org/10.32469/10355/33098","code":true}]}]},"links":{"outbound_url":"https://hdl.handle.net/10355/33098","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Chandrasekhar, Meera","Guha, Suchi"]},{"key":"dc:creator","label":"Author","values":["Paudel, Keshab Raj, 1973-"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2013-03-04T17:04:55Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2013-03-04T17:04:55Z"]},{"key":"dc:date.issued","label":"Date","values":["2012"]},{"key":"dc:publisher","label":"Institution","values":["University of Missouri--Columbia"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Physics and astronomy (MU)"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Doctoral"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph. 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Raman studies under pressure show that the molecular ordering is barely affected by pressure in the pristine P3HT, whereas the ordering decreases with pressure in PCBM blended P3HT beyond 3.0 GPa."]},{"key":"dc:title","label":"Title","values":["High pressure spectroscopic studies of organic device materials"]}]}],"canonical_facts":{"dc:contributor.advisor":["Chandrasekhar, Meera","Guha, Suchi"],"dc:creator":["Paudel, Keshab Raj, 1973-"],"dc:date.accessioned":["2013-03-04T17:04:55Z"],"dc:date.available":["2013-03-04T17:04:55Z"],"dc:date.issued":["2012"],"dc:description":["Title from PDF of title page (University of Missouri--Columbia, viewed on March 4, 2013).","The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file.","Dissertation advisors: Dr. Meera Chandrasekhar and Dr. Suchi Guha","Includes bibliographical references.","Vita.","Ph. D. University of Missouri--Columbia 2012.","\"December 2012\""],"dc:description.abstract":["A comparison of photoluminescence spectra of as-is and thermally cycled di-octyl substituted polyfluorene (PF8) under pressure has been used to disentangle inter- and intra-chain interactions. Raman study of this system shows a strong electron-phonon interaction between the Raman phonon and the electronic continuum. Photoluminescence and phosphorescence studies of a ladder type poly(para-phenylene) (PhLPPP) under pressure have given for the first time an evidence that the singlet-triplet splitting remains almost a constant under enhanced intermolecular interaction. For polymer bulkheterojunctions of P3HT or PhLPPP with PCBM, the photoluminescence and absorption spectra reveal that the LUMO band-edge off-set increases with pressure. Raman studies under pressure show that the molecular ordering is barely affected by pressure in the pristine P3HT, whereas the ordering decreases with pressure in PCBM blended P3HT beyond 3.0 GPa."],"dc:identifier.doi":["https://doi.org/10.32469/10355/33098"],"dc:identifier.uri":["https://hdl.handle.net/10355/33098"],"dc:language":["English"],"dc:language.iso":["eng"],"dc:publisher":["University of Missouri--Columbia"],"dc:rights":["OpenAccess."],"dc:subject":["singlet-triplet splitting","di-octyl substituted polyfluorene","Raman phonon","electronic continuum"],"dc:title":["High pressure spectroscopic studies of organic device materials"],"dc:type":["Thesis"],"thesis:degree_discipline":["Physics and astronomy (MU)"],"thesis:degree_level":["Doctoral"],"thesis:degree_name":["Ph. D."],"thesis:institution_name":["University of Missouri--Columbia"]},"updated_at":"2026-07-24T03:07:35Z"}