Scanning tunneling microscopy and spectroscopy of wet chemically synthesized porous graphene nanoribbons on hydrogen passivated silicon (100)

Parsons, Kaitlyn Ann

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https://hdl.handle.net/2142/109379 Copy

Description

Title

Scanning tunneling microscopy and spectroscopy of wet chemically synthesized porous graphene nanoribbons on hydrogen passivated silicon (100)

Author(s)

Parsons, Kaitlyn Ann

Issue Date

2020-11-30

Director of Research (if dissertation) or Advisor (if thesis)

Lyding, Joseph W

Doctoral Committee Chair(s)

Lyding, Joseph W

Committee Member(s)

• Girolami, Gregory S
• Li, Xiuling
• Zhu, Wenjuan

Department of Study

Electrical & Computer Eng

Discipline

Electrical & Computer Engr

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

• scanning tunneling microscopy
• scanning tunneling spectroscopy
• graphene nanoribbons
• hydrogen passivation
• silicon

Abstract

This dissertation investigates wet-chemically synthesized atomically precise porous graphene nanoribbons (GNRs) exfoliated onto hydrogen passivated silicon H:Si(100) substrates using a dry contact transfer (DCT) method under ultrahigh-vacuum (UHV) conditions. The porous GNRs are characterized in UHV using scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS). A unique electronic feature is observed at the pore sites in the STM topographic images. STS measurements indicate the presence of the pores significantly increases the bandgap compared to the surrounding GNR material. First-principles density functional theory (DFT) simulations are used to predict the band structure for the porous GNR. This is compared to theoretical simulations of the non-porous GNR case in order to elucidate how the addition of the pore to the GNR affects the electronic structure. Experimental results and first-principles computation modeling were shown to be in good agreement. Atomically precise GNRs with strategically placed pores expand the possibilities for applications in single-molecule detection and selectivity, including desalination and DNA sequencing.

Graduation Semester

2020-12

Type of Resource

Thesis

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http://hdl.handle.net/2142/109379

Copyright and License Information

Copyright 2020 Kaitlyn Parsons

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