Accession Number:

AD1155156

Title:

Programming of Graphene Properties via Defect Design and Characterization

Descriptive Note:

[Technical Report, Final Report]

Corporate Author:

HANYANG INDUSTRY-UNIVERSITY COOPERATION

Personal Author(s):

• Park, Won

Report Date:

2021-11-22

Pagination or Media Count:

23

Abstract:

Defects play an important role in crystalline materials, making the actual properties quite different from defect-free perfect crystals. For example, in semiconductors, an extremely small amount of impurity dopants can significantly change the electrical properties so that Si can have either p-type or n-type characteristics. Especially in graphene and other 2-dimensional 2D materials, most defects are exposed to the outside and thus, they are supposed to have a more critical effect on the properties. Here, we propose programming graphene properties via defect design and functionalization on the basis of high-quality nano-patterned graphene with disordering yet with contamination-free edges and a near-single crystal structure. Most chemical vapor deposition CVD grown graphene has many defects, such as grain boundaries GBs, point defects, and wrinkles. These defects are developed randomly, and thus they are difficult to control. So, to engineer the defects and to program the properties, we first established the growth of high-quality, single-crystal graphene to minimize the unintentionally incorporated defects such as GBs. We then carried out engineering edge defects in graphene by introducing artificial defects in graphene or growing edge-controlled flakes and characterized these defects depending on the edge chirality. Although conventional graphene patterning via lithography and etching has been suggested to introduce edge defects in graphene, this approach causes C atoms at the edges to become disordered and contaminated with residues and thus lose the intrinsic properties of the defects. Here, we suggested defect design and functionalization by developing contamination-free edge defects and wrinkles.

Descriptors:

• chemical vapor deposition
• crystals
• field effect transistors
• semiconductors
• spectra
• two dimensional
• two-dimensional materials
• air force
• density functional theory
• materials
• raman spectra
• spectroscopy
• air force research laboratories
• band gaps
• crystal structure
• diffraction
• electrical properties

Subject Categories:

• Crystallography
• Mechanics
• Miscellaneous Materials

Distribution Statement:

[A, Approved For Public Release]