BORON DOPING OF SINGLE WALLED CARBON NANOTUBES
Open Access
- Author:
- Liu, Xiaoming
- Graduate Program:
- Physics
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- September 04, 2009
- Committee Members:
- Peter C Eklund, Dissertation Advisor/Co-Advisor
Nitin Samarth, Committee Chair/Co-Chair
Jorge Osvaldo Sofo, Committee Member
Vincent Henry Crespi, Committee Member
John V Badding, Committee Member
Jayanth R Banavar, Committee Member - Keywords:
- Carbon nanotube
boron doping
conducting films - Abstract:
- This thesis addresses the improvement of electrical properties of single walled carbon nanotubes (SWNTs), grown by different techniques, by a stable substitutional boron doping. The B-SWNTs material was created in four different ways, and <1 at.% boron was found in the SWNTs bundles with electron energy loss spectroscopy (EELS). The p-type doping is confirmed by Raman spectroscopy. The Raman D-band results and the line shape of EELS spectra show that boron is fitted into the sp2 lattice of the tube wall. B-doping was found to downshift the positions of the optical absorption bands associated with van Hove singularities (E11s E22s and E11m ) by ~40 meV relative to their positions in the acid treated and annealed SWNTs. Optical transmission studies show that B-doping increases the number of free carriers, and that it does not significantly affect the optical transmittance of the B-SWNTs films in the visible region. We found that boron-doping lowers the sheet resistance by 75% of the pristine SWNTs films. Besides, boron-doped SWNTs may provide a better modification of the semi-conducting SWNTs in a stable way. We suggest that B-SWNTs films may be a potential material for future electronic devices, such as touch-screens, organic electronics device, organic solar cells and flexible display screens, because of its strengths, including transparency, high T/R and flexibility, low cost, and easy deposition on plastic substrates.