Advanced search options

Advanced Search Options 🞨

Browse by author name (“Author name starts with…”).

Find ETDs with:

in
/  
in
/  
in
/  
in

Written in Published in Earliest date Latest date

Sorted by

Results per page:

You searched for id:"handle:10919/97366". One record found.

Search Limiters

Last 2 Years | English Only

No search limiters apply to these results.

▼ Search Limiters


Virginia Tech

1. Li, Yanlong. Scanning Probe Microscopy Study of Molecular Self Assembly Behavior on Graphene Two-dimensional Material.

Degree: PhD, Physics, 2020, Virginia Tech

As the first physical isolated two-dimensional (2D) material, graphene has attracted exceptional scientific attention. Due to its impressive properties including high carrier density, flexibility and transparency, graphene has numerous potential applications, such as solar cell, sensors and electronics. 2D molecular self-assembly is an area that focuses on organization and interaction between self-assembly behaviors of molecules on surface. Graphene is an excellent substrate for the study of molecular self-assembly behavior, and study of molecular study is very important for graphene due to potential applications of molecules on graphene. In this thesis, we present investigations of the molecular self-assembly of PCBM, C60, PTCDA and [email protected] on graphene substrate. First, we report the two types of bilayer PCBM configuration on HOPG with a step height of 1.68 nm and 1.23 nm, as well as two types of monolayer PCBM configuration with a step height of 0.7 nm and 0.88 nm, respectively. On graphene, PCBM forms one type of PCBM bilayer with a step height of 1.37 nm and one type of PCBM monolayer with a step height of 0.87 nm. By building and analyzing the models of PCBM bilayers and monolayers, we believe the main differences between two configurations of PCBM bilayer and monolayer is the tilt angle between PCBM and HOPG, which makes type I configuration the higher molecule density and binding energy. Secondly, we report the investigation of self-assembly behaviors of C60 and PTCDA on flat graphene and rippled graphene by experimental scanning tunneling microscope (STM) and theoretical density functional theory (DFT). On flat graphene, C60 forms hexagon close pack (hcp) structure, while PTCDA forms herringbone structure. On rippled graphene, C60 forms quasi-hcp structure while PTCDA forms disordered herringbone structure. By DFT calculation, we study the effect of graphene curvature on spherical C60 and planar PTCDA. Finally, we report a STM study of a monolayer of [email protected] on graphene substrate. [email protected] forms hcp structure in a small domain with a step height of 0.88 nm and lattice constant of 1.15 nm. According to our DFT calculation, for the optimal organization of [email protected] and graphene, the gap between [email protected] and graphene is 3.3 Å and the binding energy is 0.95 eV. Besides, the distance between [email protected] and [email protected] is 3.5 Å and the binding energy is 0.32 eV. Advisors/Committee Members: Heflin, James Randy (committeechair), Robinson, Hans (committee member), Cheng, Shengfeng (committee member), Tao, Chenggang (committee member).

Subjects/Keywords: Scanning Tunneling Microscope (STM); Molecular Self Assembly; Atomic Force Microscope (AFM); Graphene; 2D materials

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Li, Y. (2020). Scanning Probe Microscopy Study of Molecular Self Assembly Behavior on Graphene Two-dimensional Material. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/97366

Chicago Manual of Style (16th Edition):

Li, Yanlong. “Scanning Probe Microscopy Study of Molecular Self Assembly Behavior on Graphene Two-dimensional Material.” 2020. Doctoral Dissertation, Virginia Tech. Accessed April 09, 2020. http://hdl.handle.net/10919/97366.

MLA Handbook (7th Edition):

Li, Yanlong. “Scanning Probe Microscopy Study of Molecular Self Assembly Behavior on Graphene Two-dimensional Material.” 2020. Web. 09 Apr 2020.

Vancouver:

Li Y. Scanning Probe Microscopy Study of Molecular Self Assembly Behavior on Graphene Two-dimensional Material. [Internet] [Doctoral dissertation]. Virginia Tech; 2020. [cited 2020 Apr 09]. Available from: http://hdl.handle.net/10919/97366.

Council of Science Editors:

Li Y. Scanning Probe Microscopy Study of Molecular Self Assembly Behavior on Graphene Two-dimensional Material. [Doctoral Dissertation]. Virginia Tech; 2020. Available from: http://hdl.handle.net/10919/97366

.