{"id":{"repo_id":"umn","oai_identifier":"oai:conservancy.umn.edu:11299/102277"},"canonical_url":"https://search.dev.ndltd.org/etd/umn/oai:conservancy.umn.edu:11299/102277","repository":{"repo_id":"umn","name":"University of Minnesota","base_url":"https://conservancy.umn.edu/server/oai/request"},"display":{"title":"Nonthemal plasma synthesis of indium phosphide nanocrystals and electrical properties of doped silicon nanocrystal films.","abstract":"This thesis is concerning the plasma synthesis of semiconductor nanocrystals (NCs). Two systems of nanocrystals were studied, indium phosphide and doped silicon. A new method of synthesis of InP NCs is presented. It represents a new route for the synthesis of high quality compound semiconductor NCs. Additionally the electronic properties of doped silicon NCs were studied as a function of the doping concentration. Indium phosphide nanocrystals (InP NCs) were synthesized using a nonthermal plasma. The NCs were synthesized using a simple capacitively coupled plasma where the precursors are flowed through a 3/8” quartz tube with two outer ring electrodes. The size of the NCs was primarily controlled through the residence time of the NCs in the plasma. Residence times of 2-10 ms lead to particles with mean sizes between ~2.5-4 nm with size distributions less than 25% of the mean particle size. The mass yield for this system was found to be up to 40 mg/hr. When a ZnS shell was grown around the InP NCs, size-tunable emission from the blue-green to the red was observed. Quantum yields as high as 15% were observed with this synthesis route. This route allows for synthesis of free-standing NCs that can be easily manipulated with colloidal based techniques or included in devices without stabilizing ligands. The electrical conductivity of phosphorus doped Si NCs was studied as a function of the doping concentration. Doped Si NCs with mean sizes of 8-13 nm were spun cast onto a substrate with pre-deposited aluminum electrodes. The spin cast process produces films with zero to several monolayers of NCs. The conductivity of the films varies continuously from 10-11 S/cm for intrinsic NCs to 10-1 S/cm for highly doped NCs. These results indicate that the dopants are electrically active. The interpretation of these results means that the electronic properties of NCs can be tuned in a similar fashion as bulk semiconductors by introducing dopants. The ability to successfully dope NCs can have broad impact on the ability to form semiconductor devices.","abstract_html":"This thesis is concerning the plasma synthesis of semiconductor nanocrystals (NCs). Two systems of nanocrystals were studied, indium phosphide and doped silicon. A new method of synthesis of InP NCs is presented. It represents a new route for the synthesis of high quality compound semiconductor NCs. Additionally the electronic properties of doped silicon NCs were studied as a function of the doping concentration. Indium phosphide nanocrystals (InP NCs) were synthesized using a nonthermal plasma. The NCs were synthesized using a simple capacitively coupled plasma where the precursors are flowed through a 3/8” quartz tube with two outer ring electrodes. The size of the NCs was primarily controlled through the residence time of the NCs in the plasma. Residence times of 2-10 ms lead to particles with mean sizes between ~2.5-4 nm with size distributions less than 25% of the mean particle size. The mass yield for this system was found to be up to 40 mg/hr. When a ZnS shell was grown around the InP NCs, size-tunable emission from the blue-green to the red was observed. Quantum yields as high as 15% were observed with this synthesis route. This route allows for synthesis of free-standing NCs that can be easily manipulated with colloidal based techniques or included in devices without stabilizing ligands. The electrical conductivity of phosphorus doped Si NCs was studied as a function of the doping concentration. Doped Si NCs with mean sizes of 8-13 nm were spun cast onto a substrate with pre-deposited aluminum electrodes. The spin cast process produces films with zero to several monolayers of NCs. The conductivity of the films varies continuously from 10-11 S/cm for intrinsic NCs to 10-1 S/cm for highly doped NCs. These results indicate that the dopants are electrically active. The interpretation of these results means that the electronic properties of NCs can be tuned in a similar fashion as bulk semiconductors by introducing dopants. The ability to successfully dope NCs can have broad impact on the ability to form semiconductor devices.","abstract_has_math":false,"creators":["Gresback, Ryan Gerard"],"institution":null,"degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2010,"date_issued":"2010-02","date_published":"2010-02","updated_at":"2026-07-24T05:20:09Z","subjects":["Plasma synthesis","Nanocrystals","Plasma","Doping concentration","Electronic properties","Mechanical Engineering"],"languages":["en_US"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://purl.umn.edu/102277","outbound_label":"Repository record","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Gresback, Ryan Gerard"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2011-04-05T19:00:38Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2011-04-05T19:00:38Z"]},{"key":"dc:date.issued","label":"Date","values":["2010-02"]},{"key":"dc:type","label":"Dc Type","values":["Thesis or Dissertation"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Plasma synthesis","Nanocrystals","Plasma","Doping concentration","Electronic properties","Mechanical Engineering"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en_US"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://purl.umn.edu/102277"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["University of Minnesota M.S. thesis. February 2010. Major: Mechanical Engineering. Advisor: Professor Uwe Kortshagen. 1 computer file (PDF); vi, 56 pages, appendices A-B."]},{"key":"dc:description.abstract","label":"Abstract","values":["This thesis is concerning the plasma synthesis of semiconductor nanocrystals (NCs). Two systems of nanocrystals were studied, indium phosphide and doped silicon. A new method of synthesis of InP NCs is presented. It represents a new route for the synthesis of high quality compound semiconductor NCs. Additionally the electronic properties of doped silicon NCs were studied as a function of the doping concentration. Indium phosphide nanocrystals (InP NCs) were synthesized using a nonthermal plasma. The NCs were synthesized using a simple capacitively coupled plasma where the precursors are flowed through a 3/8” quartz tube with two outer ring electrodes. The size of the NCs was primarily controlled through the residence time of the NCs in the plasma. Residence times of 2-10 ms lead to particles with mean sizes between ~2.5-4 nm with size distributions less than 25% of the mean particle size. The mass yield for this system was found to be up to 40 mg/hr. When a ZnS shell was grown around the InP NCs, size-tunable emission from the blue-green to the red was observed. Quantum yields as high as 15% were observed with this synthesis route. This route allows for synthesis of free-standing NCs that can be easily manipulated with colloidal based techniques or included in devices without stabilizing ligands. The electrical conductivity of phosphorus doped Si NCs was studied as a function of the doping concentration. Doped Si NCs with mean sizes of 8-13 nm were spun cast onto a substrate with pre-deposited aluminum electrodes. The spin cast process produces films with zero to several monolayers of NCs. The conductivity of the films varies continuously from 10-11 S/cm for intrinsic NCs to 10-1 S/cm for highly doped NCs. These results indicate that the dopants are electrically active. The interpretation of these results means that the electronic properties of NCs can be tuned in a similar fashion as bulk semiconductors by introducing dopants. The ability to successfully dope NCs can have broad impact on the ability to form semiconductor devices."]},{"key":"dc:title","label":"Title","values":["Nonthemal plasma synthesis of indium phosphide nanocrystals and electrical properties of doped silicon nanocrystal films."]}]}],"canonical_facts":{"dc:creator":["Gresback, Ryan Gerard"],"dc:date.accessioned":["2011-04-05T19:00:38Z"],"dc:date.available":["2011-04-05T19:00:38Z"],"dc:date.issued":["2010-02"],"dc:description":["University of Minnesota M.S. thesis. February 2010. Major: Mechanical Engineering. Advisor: Professor Uwe Kortshagen. 1 computer file (PDF); vi, 56 pages, appendices A-B."],"dc:description.abstract":["This thesis is concerning the plasma synthesis of semiconductor nanocrystals (NCs). Two systems of nanocrystals were studied, indium phosphide and doped silicon. A new method of synthesis of InP NCs is presented. It represents a new route for the synthesis of high quality compound semiconductor NCs. Additionally the electronic properties of doped silicon NCs were studied as a function of the doping concentration. Indium phosphide nanocrystals (InP NCs) were synthesized using a nonthermal plasma. The NCs were synthesized using a simple capacitively coupled plasma where the precursors are flowed through a 3/8” quartz tube with two outer ring electrodes. The size of the NCs was primarily controlled through the residence time of the NCs in the plasma. Residence times of 2-10 ms lead to particles with mean sizes between ~2.5-4 nm with size distributions less than 25% of the mean particle size. The mass yield for this system was found to be up to 40 mg/hr. When a ZnS shell was grown around the InP NCs, size-tunable emission from the blue-green to the red was observed. Quantum yields as high as 15% were observed with this synthesis route. This route allows for synthesis of free-standing NCs that can be easily manipulated with colloidal based techniques or included in devices without stabilizing ligands. The electrical conductivity of phosphorus doped Si NCs was studied as a function of the doping concentration. Doped Si NCs with mean sizes of 8-13 nm were spun cast onto a substrate with pre-deposited aluminum electrodes. The spin cast process produces films with zero to several monolayers of NCs. The conductivity of the films varies continuously from 10-11 S/cm for intrinsic NCs to 10-1 S/cm for highly doped NCs. These results indicate that the dopants are electrically active. The interpretation of these results means that the electronic properties of NCs can be tuned in a similar fashion as bulk semiconductors by introducing dopants. The ability to successfully dope NCs can have broad impact on the ability to form semiconductor devices."],"dc:identifier.uri":["http://purl.umn.edu/102277"],"dc:language.iso":["en_US"],"dc:subject":["Plasma synthesis","Nanocrystals","Plasma","Doping concentration","Electronic properties","Mechanical Engineering"],"dc:title":["Nonthemal plasma synthesis of indium phosphide nanocrystals and electrical properties of doped silicon nanocrystal films."],"dc:type":["Thesis or Dissertation"]},"updated_at":"2026-07-24T05:20:09Z"}