Description:
Reference #: 01008
The University of South Carolina is offering licensing opportunities for a method of achieving thin to thick graphene from a few monolayers to several microns with excellent surface morphology and uniformity, the combination of which is not realizable by other techniques.
Invention Description:
The subject invention is a novel method of growing epitaxial graphene by changing the silicon loss mechanism necessary for subsequent C-rich layers to form. This allows thickness and electronic properties to be controlled simultaneously, breaking the fundamental trade-off between crystal quality and thickness present in traditional epitaxial growth techniques.
Advantages and Benefits:
1. Si is removed selectively and efficiently from the SiC surface unlike other etching methods (e.g. hydrogen or HCI).
2. Growth can be performed with any cut off substrate (e.g. 0°, 2°, 4°, 8°, etc.) or any polytype (3C, 4H, 6H, etc.) since silicon removal process is enhanced irrespective of substrate type.
3. Applicable to any growth reactor (e.g. horizontal or vertical)
Potential Applications:
While current graphene growth has focused on producing 1 to 2 atomic monolayers for radio frequency applications, there is an emerging need for thicker layers for engineered carbon electrodes for use in batteries, hydrogen storage, emissions sensing, highly efficient solar cells, fuel cells, and other applications where accessible surface area is critical.
Testing and Development:
X-ray photoelectron spectroscopy showed a growth rate of more than 100 monolayers/hour of extremely high quality epitaxial graphene, which is much faster than any other technique previously used. The Raman spectrum of the film showed an intrinsic G-peak of approximately 1580cm-1, a disorder D-peak at approximately 1350cm-1, and a double resonant, stacking dependent 2D-peak of about 2700cm-1. Other key Raman metrics further illustrate the thick, high quality of the graphene: very low ration of D/G intensity (comparable to the best in literature), extremely sharp 2D-peak (suitable for electronic applications because of the film’s superior electronic properties), symmetric 2D-peak (critical for improvement over traditional graphene electrodes), and no measurable peak around 2950cm-1 (indicative of the planar registry of the film to the substrate, which is very surprising considering the thickness of the films).