Enhancement of the electrical properties of graphene for electronic devices

Graphene, a one-atom-thick two-dimensional material, has drawn great interest for many electronic and optoelectronic applications due to its extraordinary properties. The properties of the graphene can be modified with different chemical methods and introduced new properties, which widens its potential for applications. The non-covalent modification of graphene is one of the basic techniques for modifying the electrical properties of graphene without disrupting the structure.
In this thesis, the high-quality graphene has been synthesized and electrical properties of graphene have been tuned by using self-assembly monolayers (SAMs). For graphene synthesis, copper foil pre-treatment was performed using the mechanical-chemical polishing method. Afterwords, graphene films were synthesized on pre-cleaned copper foil by atmospheric pressure chemical vapor deposition under the optimized conditions. It was found that copper surface and growth conditions play a significant role in high quality graphene growth. Additionally, sheet resistance and mobility of graphene were measured by Hall Effect measurement system. The sheet resistance of graphene was found about 718 Ω/sq with 96.8% of transmittance. Furthermore, obtained graphene was doped with surface transfer method using various SAMs including 4-Fluorophenyl boronic acid, 3,4-Difluorophenyl boronic acid, 3,4,5-Trimethoxyphenyl boronic acid, Boron trifluoride dimethyl etherate, TPA and CAR. It has been found that SAMs modify the density of its charge carriers, thus, the electrical properties of graphene films have been altered. As a result, depending on the type of SAMs the carrier type of graphene can controllably be changed from p-type to n-type and the electrical properties of graphene could be modified by several SAMs. We believed that this study could open up a wide range of possibilities for electronic and optoelectronic applications.