{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/129743"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/129743","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"The electronic characterization of a type 9A graphene nanoribbon using scanning tunneling microscopy and spectroscopy","abstract":"Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2027-05-01","abstract_html":"Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2027-05-01","abstract_has_math":false,"creators":["Berg, Abigail W"],"institution":"University of Illinois Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Electrical & Computer Engr","degree_department":null,"school":null,"contributors":["Lyding, Joseph W","Zhu, Wenjuan","Choquette, Kent D","Sinitskii, Alexander"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2025,"date_issued":"2025-05-02","date_published":"2025-05-02","updated_at":"2026-07-22T22:25:05Z","subjects":["graphene","graphene nanoribbon","carbon-based materials","low-dimensional materials","2D materials","scanning tunneling microscopy","spectroscopy"],"languages":["en","eng"],"rights":["Copyright 2025 Abigail W. Berg"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://hdl.handle.net/2142/129743","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Lyding, Joseph W","Zhu, Wenjuan","Choquette, Kent D","Sinitskii, Alexander"]},{"key":"dc:creator","label":"Author","values":["Berg, Abigail W"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2025-05-02","2025-05"]},{"key":"dc:type","label":"Dc Type","values":["text","Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Electrical & Computer Engr"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["graphene","graphene nanoribbon","carbon-based materials","low-dimensional materials","2D materials","scanning tunneling microscopy","spectroscopy"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en","eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2025 Abigail W. Berg"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://hdl.handle.net/2142/129743"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2027-05-01","The student, Abigail Berg, accepted the attached license on 2025-04-28 at 17:09.","The student, Abigail Berg, submitted this Dissertation for approval on 2025-04-28 at 17:10.","This Dissertation was approved for publication on 2025-05-02 at 09:01.","DSpace SAF Submission Ingestion Package generated from Vireo submission #22038 on 2025-10-19 at 19:54:27","This dissertation presents the electronic characterization of a type 9A graphene nanoribbon (GNR) synthesized through a bottom-up solution-based approach and analyzed using scanning tunneling microscopy (STM) and spectroscopy (STS). The study focuses on the structural and electronic properties of this novel GNR variant, which features functionalized end groups designed to facilitate controlled interactions and potential device integration. The GNRs were exfoliated onto hydrogen-passivated silicon (H:Si(100)) substrates using the dry contact transfer (DCT) method in an ultra-high vacuum (UHV) environment. High-resolution STM imaging revealed distinct morphological features, including an average length of 18.25 nm and occasional structural defects attributed to missing phenyl groups. The electronic properties were further investigated using STS, which showed an average bandgap of 2.13 eV, with spatial variations due to quantum confinement effects and the influence of functional end groups. Density functional theory (DFT) calculations predicted a bandgap of 1.4 eV, which increased to 3.71 eV after GW correction, closely aligning with experimental observations. Notably, bilayer GNRs were observed for the first time, demonstrating an unexpected increase in bandgap compared to monolayer counterparts, contrary to theoretical predictions. This phenomenon suggests additional interlayer interactions that warrant further investigation. Moreover, hydrogen depassivation nanolithography (NL) was employed to modify the substrate beneath the GNRs, resulting in selective pinning and local metallic behavior. These findings contribute to the broader understanding of GNR-based nanoelectronics by elucidating the impact of structural modifications on electronic properties. The observed electronic behavior, combined with the stability of the GNRs under nanolithographic modification, underscores their potential for future applications in nanoscale devices. Further research into mixed-dimensional systems incorporating GNRs and transition metal dichalcogenides (TMDs) could yield novel heterostructures with tailored electronic properties for next-generation semiconductor technologies."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["The electronic characterization of a type 9A graphene nanoribbon using scanning tunneling microscopy and spectroscopy"]}]}],"canonical_facts":{"dc:contributor":["Lyding, Joseph W","Zhu, Wenjuan","Choquette, Kent D","Sinitskii, Alexander"],"dc:creator":["Berg, Abigail W"],"dc:date":["2025-05-02","2025-05"],"dc:description":["Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2027-05-01","The student, Abigail Berg, accepted the attached license on 2025-04-28 at 17:09.","The student, Abigail Berg, submitted this Dissertation for approval on 2025-04-28 at 17:10.","This Dissertation was approved for publication on 2025-05-02 at 09:01.","DSpace SAF Submission Ingestion Package generated from Vireo submission #22038 on 2025-10-19 at 19:54:27","This dissertation presents the electronic characterization of a type 9A graphene nanoribbon (GNR) synthesized through a bottom-up solution-based approach and analyzed using scanning tunneling microscopy (STM) and spectroscopy (STS). The study focuses on the structural and electronic properties of this novel GNR variant, which features functionalized end groups designed to facilitate controlled interactions and potential device integration. The GNRs were exfoliated onto hydrogen-passivated silicon (H:Si(100)) substrates using the dry contact transfer (DCT) method in an ultra-high vacuum (UHV) environment. High-resolution STM imaging revealed distinct morphological features, including an average length of 18.25 nm and occasional structural defects attributed to missing phenyl groups. The electronic properties were further investigated using STS, which showed an average bandgap of 2.13 eV, with spatial variations due to quantum confinement effects and the influence of functional end groups. Density functional theory (DFT) calculations predicted a bandgap of 1.4 eV, which increased to 3.71 eV after GW correction, closely aligning with experimental observations. Notably, bilayer GNRs were observed for the first time, demonstrating an unexpected increase in bandgap compared to monolayer counterparts, contrary to theoretical predictions. This phenomenon suggests additional interlayer interactions that warrant further investigation. Moreover, hydrogen depassivation nanolithography (NL) was employed to modify the substrate beneath the GNRs, resulting in selective pinning and local metallic behavior. These findings contribute to the broader understanding of GNR-based nanoelectronics by elucidating the impact of structural modifications on electronic properties. The observed electronic behavior, combined with the stability of the GNRs under nanolithographic modification, underscores their potential for future applications in nanoscale devices. Further research into mixed-dimensional systems incorporating GNRs and transition metal dichalcogenides (TMDs) could yield novel heterostructures with tailored electronic properties for next-generation semiconductor technologies."],"dc:format":["application/pdf"],"dc:identifier":["https://hdl.handle.net/2142/129743"],"dc:language":["en","eng"],"dc:rights":["Copyright 2025 Abigail W. Berg"],"dc:subject":["graphene","graphene nanoribbon","carbon-based materials","low-dimensional materials","2D materials","scanning tunneling microscopy","spectroscopy"],"dc:title":["The electronic characterization of a type 9A graphene nanoribbon using scanning tunneling microscopy and spectroscopy"],"dc:type":["text","Thesis"],"thesis:degree_discipline":["Electrical & Computer Engr"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois Urbana-Champaign"]},"updated_at":"2026-07-22T22:25:05Z"}