{"id":{"repo_id":"wustl","oai_identifier":"oai:openscholarship.wustl.edu:etd-1850"},"canonical_url":"https://search.dev.ndltd.org/etd/wustl/oai:openscholarship.wustl.edu:etd-1850","repository":{"repo_id":"wustl","name":"Washington University in St. Louis","base_url":"https://openscholarship.wustl.edu/do/oai/"},"display":{"title":"Surface Passivation of Colloidal II-IV Semiconductor Quantum Belts and Quantum Wires: Synthesis, Mechanism and Optical Studies","abstract":"My research aims to study the formation mechanism of CdSe quantum belts: QBs) and the surface passivation of CdTe quantum wires: QWs). Investigation of QB morphology and QW passivation are fundamentally important to avoid nonradiative recombination and to increase electron-transport efficiency in semiconductor solar-cell devices. The origin of CdSe QBs is a lamellar structure of cadmium-octylamine precursor complex, with an intermediate state of stripe-like assembly of CdSe magic-sized nanoclusters. Transformation of: CdSe)13 nanoclusters to CdSe quantum belts: QBs) is conducted by higher annealing-temperature and confirmed by their optical and structural characterization. The QBs possess a thickness of 1.5-2.0 nm with a width of 7-15 nm and length of >1 micrometer. Most remarkably, the QBs have a superior morphology with noticeably high quantum efficiency: QE, 30 ± 10 %), comparable to quantum rods. High QE is explained by a delocalized exciton recombination with a lower density of defect sites. The colloidal CdTe quantum wires: QWs) are preferred for solar-cell applications due to a tunable diameter range: 5-60 nm), a long length dimensionality: > 5 micrometer), and near-IR band-gap emission energy: 1.5 eV). Successive surface passivation with Lewis acids and bases successfully passivates the QW surface. A significantly enhanced CdTe QW quantum efficiency: QE, 5-8 %) is achieved, which is two orders of magnitude larger than the previous disappointing QE: < 0.01 %). Enhanced photoluminescence: PL) emission reveals intrinsic higher and lower emission bands for CdTe QWs. Enhanced photoluminescence excitation: PLE) features consistently match previous theoretical calculations for electronic transitions. Significantly high QEs of CdSe QBs: 30 ± 10 %) and CdTe QWs: 5-8 %) promise colloidal 1D quantum structures suitable for bio-imaging and solar-cell applications.","abstract_html":"My research aims to study the formation mechanism of CdSe quantum belts: QBs) and the surface passivation of CdTe quantum wires: QWs). Investigation of QB morphology and QW passivation are fundamentally important to avoid nonradiative recombination and to increase electron-transport efficiency in semiconductor solar-cell devices. The origin of CdSe QBs is a lamellar structure of cadmium-octylamine precursor complex, with an intermediate state of stripe-like assembly of CdSe magic-sized nanoclusters. Transformation of: CdSe)13 nanoclusters to CdSe quantum belts: QBs) is conducted by higher annealing-temperature and confirmed by their optical and structural characterization. The QBs possess a thickness of 1.5-2.0 nm with a width of 7-15 nm and length of &gt;1 micrometer. Most remarkably, the QBs have a superior morphology with noticeably high quantum efficiency: QE, 30 ± 10 %), comparable to quantum rods. High QE is explained by a delocalized exciton recombination with a lower density of defect sites. The colloidal CdTe quantum wires: QWs) are preferred for solar-cell applications due to a tunable diameter range: 5-60 nm), a long length dimensionality: &gt; 5 micrometer), and near-IR band-gap emission energy: 1.5 eV). Successive surface passivation with Lewis acids and bases successfully passivates the QW surface. A significantly enhanced CdTe QW quantum efficiency: QE, 5-8 %) is achieved, which is two orders of magnitude larger than the previous disappointing QE: &lt; 0.01 %). Enhanced photoluminescence: PL) emission reveals intrinsic higher and lower emission bands for CdTe QWs. Enhanced photoluminescence excitation: PLE) features consistently match previous theoretical calculations for electronic transitions. Significantly high QEs of CdSe QBs: 30 ± 10 %) and CdTe QWs: 5-8 %) promise colloidal 1D quantum structures suitable for bio-imaging and solar-cell applications.","abstract_has_math":false,"creators":["Liu, Yi-Hsin"],"institution":null,"degree_name":"Doctor of Philosophy (PhD)","degree_level":"Dissertation","degree_discipline":"Chemistry","degree_department":null,"school":null,"contributors":["William Buhro"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2010,"date_issued":"2010-05-24T07:00:00Z","date_published":"2010-05-24T07:00:00Z","updated_at":"2026-07-24T06:13:05Z","subjects":["Chemistry","Inorganic","Physical","Physics","Condensed Matter","CdSe","CdTe","NANOCLUSTERS","QUANTUM BELTS","QUANTUM WIRES","SURFACE PASSIVATION"],"languages":["English (en)"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier.doi","label":"DOI","values":["https://doi.org/10.7936/K7QC01J4"],"render_values":[{"text":"https://doi.org/10.7936/K7QC01J4","href":"https://doi.org/10.7936/K7QC01J4","code":true}]}]},"links":{"outbound_url":"https://openscholarship.wustl.edu/etd/851","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["William Buhro"]},{"key":"dc:creator","label":"Author","values":["Liu, Yi-Hsin"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.available","label":"Dc Date Available","values":["2014-05-25T07:00:00Z"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Chemistry"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Doctor of Philosophy (PhD)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Chemistry","Inorganic","Physical","Physics","Condensed Matter","CdSe","CdTe","NANOCLUSTERS","QUANTUM BELTS","QUANTUM WIRES","SURFACE PASSIVATION"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["English (en)"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://openscholarship.wustl.edu/etd/851"]},{"key":"dc:identifier.doi","label":"DOI","values":["https://doi.org/10.7936/K7QC01J4"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["My research aims to study the formation mechanism of CdSe quantum belts: QBs) and the surface passivation of CdTe quantum wires: QWs). Investigation of QB morphology and QW passivation are fundamentally important to avoid nonradiative recombination and to increase electron-transport efficiency in semiconductor solar-cell devices. The origin of CdSe QBs is a lamellar structure of cadmium-octylamine precursor complex, with an intermediate state of stripe-like assembly of CdSe magic-sized nanoclusters. Transformation of: CdSe)13 nanoclusters to CdSe quantum belts: QBs) is conducted by higher annealing-temperature and confirmed by their optical and structural characterization. The QBs possess a thickness of 1.5-2.0 nm with a width of 7-15 nm and length of >1 micrometer. Most remarkably, the QBs have a superior morphology with noticeably high quantum efficiency: QE, 30 ± 10 %), comparable to quantum rods. High QE is explained by a delocalized exciton recombination with a lower density of defect sites. The colloidal CdTe quantum wires: QWs) are preferred for solar-cell applications due to a tunable diameter range: 5-60 nm), a long length dimensionality: > 5 micrometer), and near-IR band-gap emission energy: 1.5 eV). Successive surface passivation with Lewis acids and bases successfully passivates the QW surface. A significantly enhanced CdTe QW quantum efficiency: QE, 5-8 %) is achieved, which is two orders of magnitude larger than the previous disappointing QE: < 0.01 %). Enhanced photoluminescence: PL) emission reveals intrinsic higher and lower emission bands for CdTe QWs. Enhanced photoluminescence excitation: PLE) features consistently match previous theoretical calculations for electronic transitions. Significantly high QEs of CdSe QBs: 30 ± 10 %) and CdTe QWs: 5-8 %) promise colloidal 1D quantum structures suitable for bio-imaging and solar-cell applications."]},{"key":"dc:title","label":"Title","values":["Surface Passivation of Colloidal II-IV Semiconductor Quantum Belts and Quantum Wires: Synthesis, Mechanism and Optical Studies"]}]}],"canonical_facts":{"dc:contributor":["William Buhro"],"dc:creator":["Liu, Yi-Hsin"],"dc:date.available":["2014-05-25T07:00:00Z"],"dc:description.abstract":["My research aims to study the formation mechanism of CdSe quantum belts: QBs) and the surface passivation of CdTe quantum wires: QWs). Investigation of QB morphology and QW passivation are fundamentally important to avoid nonradiative recombination and to increase electron-transport efficiency in semiconductor solar-cell devices. The origin of CdSe QBs is a lamellar structure of cadmium-octylamine precursor complex, with an intermediate state of stripe-like assembly of CdSe magic-sized nanoclusters. Transformation of: CdSe)13 nanoclusters to CdSe quantum belts: QBs) is conducted by higher annealing-temperature and confirmed by their optical and structural characterization. The QBs possess a thickness of 1.5-2.0 nm with a width of 7-15 nm and length of >1 micrometer. Most remarkably, the QBs have a superior morphology with noticeably high quantum efficiency: QE, 30 ± 10 %), comparable to quantum rods. High QE is explained by a delocalized exciton recombination with a lower density of defect sites. The colloidal CdTe quantum wires: QWs) are preferred for solar-cell applications due to a tunable diameter range: 5-60 nm), a long length dimensionality: > 5 micrometer), and near-IR band-gap emission energy: 1.5 eV). Successive surface passivation with Lewis acids and bases successfully passivates the QW surface. A significantly enhanced CdTe QW quantum efficiency: QE, 5-8 %) is achieved, which is two orders of magnitude larger than the previous disappointing QE: < 0.01 %). Enhanced photoluminescence: PL) emission reveals intrinsic higher and lower emission bands for CdTe QWs. Enhanced photoluminescence excitation: PLE) features consistently match previous theoretical calculations for electronic transitions. Significantly high QEs of CdSe QBs: 30 ± 10 %) and CdTe QWs: 5-8 %) promise colloidal 1D quantum structures suitable for bio-imaging and solar-cell applications."],"dc:identifier":["https://openscholarship.wustl.edu/etd/851"],"dc:identifier.doi":["https://doi.org/10.7936/K7QC01J4"],"dc:language":["English (en)"],"dc:subject":["Chemistry","Inorganic","Physical","Physics","Condensed Matter","CdSe","CdTe","NANOCLUSTERS","QUANTUM BELTS","QUANTUM WIRES","SURFACE PASSIVATION"],"dc:title":["Surface Passivation of Colloidal II-IV Semiconductor Quantum Belts and Quantum Wires: Synthesis, Mechanism and Optical Studies"],"thesis:degree_discipline":["Chemistry"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Doctor of Philosophy (PhD)"]},"updated_at":"2026-07-24T06:13:05Z"}