{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/99139"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/99139","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Electronic devices based on 2D material: fabrication, characterization and analysis","abstract":"Two-dimensional (2D) crystals are layered materials with strong in-plane covalent bonding and weak Van der Waals interlayer coupling. Stable 2D materials range from insulators, to semiconductors, to metals and even superconductors. Compared to their bulk counterparts, 2D materials show many inherent unique properties in their atomically thin layers, such as high flexibility, high surface-to-bulk ratio and absence of surface dangling bonds. These distinctive properties make 2D materials promising in many applications, including logic gates, flexible electronics, communication and biomedical sensing. A successful pathway to develop these materials into mature future devices relies on characterization of their electronic properties and incorporating them with other materials. In this thesis, we studied the intrinsic and extrinsic properties of black phosphorus (BP) by AC conductance and capacitance methods. Black phosphorus capacitors with various types of gate dielectrics were fabricated and measured at varying temperatures. From the temperature dependence of the transition frequency, we determined the bandgap of the ~50 nm black phosphorus is 0.31 eV, while, from electrostatic models, our simulated bandgap is ~0.37 eV and doping is ~3 × 1018 cm-3. From the AC conductance of the BP/Al2O3 and BP/boron nitride (BN) capacitors, we extracted the interface trap density and time constant and found that the interface trap density in Al2O3 is about 10 times that in BP/BN capacitors, indicating the superior quality of the single-crystal BN. We confirmed that the interface trap density increases and the time constant decreases as the trap level approaches the valence band. We also found that BP is naturally p-type doped, and the doping concentration in BP/BN capacitors is much higher than that in BP/Al2O3 capacitors. This may be due to the fact that the Al2O3 deposited by ALD introduces n-type doping in the black phosphorus. These characterization techniques along with the intrinsic and extrinsic properties of the black phosphors obtained in this study will be very important for designing and optimizing electronic devices (such as metal-oxide field effect transistors, tunneling field effect transistor, and resonant tunneling diodes) based on BP.","abstract_html":"Two-dimensional (2D) crystals are layered materials with strong in-plane covalent bonding and weak Van der Waals interlayer coupling. Stable 2D materials range from insulators, to semiconductors, to metals and even superconductors. Compared to their bulk counterparts, 2D materials show many inherent unique properties in their atomically thin layers, such as high flexibility, high surface-to-bulk ratio and absence of surface dangling bonds. These distinctive properties make 2D materials promising in many applications, including logic gates, flexible electronics, communication and biomedical sensing. A successful pathway to develop these materials into mature future devices relies on characterization of their electronic properties and incorporating them with other materials. In this thesis, we studied the intrinsic and extrinsic properties of black phosphorus (BP) by AC conductance and capacitance methods. Black phosphorus capacitors with various types of gate dielectrics were fabricated and measured at varying temperatures. From the temperature dependence of the transition frequency, we determined the bandgap of the ~50 nm black phosphorus is 0.31 eV, while, from electrostatic models, our simulated bandgap is ~0.37 eV and doping is ~3 × 1018 cm-3. From the AC conductance of the BP/Al2O3 and BP/boron nitride (BN) capacitors, we extracted the interface trap density and time constant and found that the interface trap density in Al2O3 is about 10 times that in BP/BN capacitors, indicating the superior quality of the single-crystal BN. We confirmed that the interface trap density increases and the time constant decreases as the trap level approaches the valence band. We also found that BP is naturally p-type doped, and the doping concentration in BP/BN capacitors is much higher than that in BP/Al2O3 capacitors. This may be due to the fact that the Al2O3 deposited by ALD introduces n-type doping in the black phosphorus. These characterization techniques along with the intrinsic and extrinsic properties of the black phosphors obtained in this study will be very important for designing and optimizing electronic devices (such as metal-oxide field effect transistors, tunneling field effect transistor, and resonant tunneling diodes) based on BP.","abstract_has_math":false,"creators":["Liu, Jialun"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"M.S.","degree_level":"Thesis","degree_discipline":"Electrical & Computer Engr","degree_department":null,"school":null,"contributors":["Zhu, Wenjuan"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2018,"date_issued":"2018-03-02T20:02:39Z","date_published":"2018-03-02T20:02:39Z","updated_at":"2026-07-22T22:24:37Z","subjects":["Two-dimensional material","Black phosphorus","C-V analysis"],"languages":["en"],"rights":["Copyright 2017 Jialun Liu"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/99139","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Zhu, Wenjuan"]},{"key":"dc:creator","label":"Author","values":["Liu, Jialun"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2018-03-02T20:02:39Z","2020-03-03T10:15:39Z","2017-07-21","2017-08"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Electrical & Computer Engr"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M.S."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Two-dimensional material","Black phosphorus","C-V analysis"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2017 Jialun Liu"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/99139"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Two-dimensional (2D) crystals are layered materials with strong in-plane covalent bonding and weak Van der Waals interlayer coupling. Stable 2D materials range from insulators, to semiconductors, to metals and even superconductors. Compared to their bulk counterparts, 2D materials show many inherent unique properties in their atomically thin layers, such as high flexibility, high surface-to-bulk ratio and absence of surface dangling bonds. These distinctive properties make 2D materials promising in many applications, including logic gates, flexible electronics, communication and biomedical sensing. A successful pathway to develop these materials into mature future devices relies on characterization of their electronic properties and incorporating them with other materials. In this thesis, we studied the intrinsic and extrinsic properties of black phosphorus (BP) by AC conductance and capacitance methods. Black phosphorus capacitors with various types of gate dielectrics were fabricated and measured at varying temperatures. From the temperature dependence of the transition frequency, we determined the bandgap of the ~50 nm black phosphorus is 0.31 eV, while, from electrostatic models, our simulated bandgap is ~0.37 eV and doping is ~3 × 1018 cm-3. From the AC conductance of the BP/Al2O3 and BP/boron nitride (BN) capacitors, we extracted the interface trap density and time constant and found that the interface trap density in Al2O3 is about 10 times that in BP/BN capacitors, indicating the superior quality of the single-crystal BN. We confirmed that the interface trap density increases and the time constant decreases as the trap level approaches the valence band. We also found that BP is naturally p-type doped, and the doping concentration in BP/BN capacitors is much higher than that in BP/Al2O3 capacitors. This may be due to the fact that the Al2O3 deposited by ALD introduces n-type doping in the black phosphorus. These characterization techniques along with the intrinsic and extrinsic properties of the black phosphors obtained in this study will be very important for designing and optimizing electronic devices (such as metal-oxide field effect transistors, tunneling field effect transistor, and resonant tunneling diodes) based on BP.","Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2019-08-01","The student, Jialun Liu, accepted the attached license on 2017-07-21 at 11:25.","The student, Jialun Liu, submitted this Thesis for approval on 2017-07-21 at 11:37.","This Thesis was approved for publication on 2017-07-21 at 12:28.","DSpace SAF Submission Ingestion Package generated from Vireo submission #11567 on 2018-03-02 at 13:03:09","Made available in DSpace on 2018-03-02T20:02:39Z (GMT). No. of bitstreams: 2 LIU-THESIS-2017.pdf: 2194641 bytes, checksum: ab1d0c766fc50f3cc51ca7160bec23d2 (MD5) LICENSE.txt: 4207 bytes, checksum: f17af3982d985198026bd251459b7440 (MD5) Previous issue date: 2017-07-21","Embargo set by: Seth Robbins for item 105094 Lift date: 2020-03-02T20:02:46Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system","U of I Only Restriction Lifted for Item 105094 on 2020-03-03T10:15:39Z."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Electronic devices based on 2D material: fabrication, characterization and analysis"]}]}],"canonical_facts":{"dc:contributor":["Zhu, Wenjuan"],"dc:creator":["Liu, Jialun"],"dc:date":["2018-03-02T20:02:39Z","2020-03-03T10:15:39Z","2017-07-21","2017-08"],"dc:description":["Two-dimensional (2D) crystals are layered materials with strong in-plane covalent bonding and weak Van der Waals interlayer coupling. Stable 2D materials range from insulators, to semiconductors, to metals and even superconductors. Compared to their bulk counterparts, 2D materials show many inherent unique properties in their atomically thin layers, such as high flexibility, high surface-to-bulk ratio and absence of surface dangling bonds. These distinctive properties make 2D materials promising in many applications, including logic gates, flexible electronics, communication and biomedical sensing. A successful pathway to develop these materials into mature future devices relies on characterization of their electronic properties and incorporating them with other materials. In this thesis, we studied the intrinsic and extrinsic properties of black phosphorus (BP) by AC conductance and capacitance methods. Black phosphorus capacitors with various types of gate dielectrics were fabricated and measured at varying temperatures. From the temperature dependence of the transition frequency, we determined the bandgap of the ~50 nm black phosphorus is 0.31 eV, while, from electrostatic models, our simulated bandgap is ~0.37 eV and doping is ~3 × 1018 cm-3. From the AC conductance of the BP/Al2O3 and BP/boron nitride (BN) capacitors, we extracted the interface trap density and time constant and found that the interface trap density in Al2O3 is about 10 times that in BP/BN capacitors, indicating the superior quality of the single-crystal BN. We confirmed that the interface trap density increases and the time constant decreases as the trap level approaches the valence band. We also found that BP is naturally p-type doped, and the doping concentration in BP/BN capacitors is much higher than that in BP/Al2O3 capacitors. This may be due to the fact that the Al2O3 deposited by ALD introduces n-type doping in the black phosphorus. These characterization techniques along with the intrinsic and extrinsic properties of the black phosphors obtained in this study will be very important for designing and optimizing electronic devices (such as metal-oxide field effect transistors, tunneling field effect transistor, and resonant tunneling diodes) based on BP.","Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2019-08-01","The student, Jialun Liu, accepted the attached license on 2017-07-21 at 11:25.","The student, Jialun Liu, submitted this Thesis for approval on 2017-07-21 at 11:37.","This Thesis was approved for publication on 2017-07-21 at 12:28.","DSpace SAF Submission Ingestion Package generated from Vireo submission #11567 on 2018-03-02 at 13:03:09","Made available in DSpace on 2018-03-02T20:02:39Z (GMT). No. of bitstreams: 2 LIU-THESIS-2017.pdf: 2194641 bytes, checksum: ab1d0c766fc50f3cc51ca7160bec23d2 (MD5) LICENSE.txt: 4207 bytes, checksum: f17af3982d985198026bd251459b7440 (MD5) Previous issue date: 2017-07-21","Embargo set by: Seth Robbins for item 105094 Lift date: 2020-03-02T20:02:46Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system","U of I Only Restriction Lifted for Item 105094 on 2020-03-03T10:15:39Z."],"dc:format":["application/pdf"],"dc:identifier":["http://hdl.handle.net/2142/99139"],"dc:language":["en"],"dc:rights":["Copyright 2017 Jialun Liu"],"dc:subject":["Two-dimensional material","Black phosphorus","C-V analysis"],"dc:title":["Electronic devices based on 2D material: fabrication, characterization and analysis"],"dc:type":["text"],"thesis:degree_discipline":["Electrical & Computer Engr"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["M.S."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:24:37Z"}