Theoretical study of thermal transport in graphene nanostructures

• Main Author: Su, Kelvin Kewen.
• Other Authors: Tay Beng Kang
• Format: Final Year Project
• Language: English
• Published: 2010
• Subjects: DRNTU::Engineering::Electrical and electronic engineering::Molecular electronics
• Online Access: http://hdl.handle.net/10356/38707
• Institution: Nanyang Technological University

Thermal management becomes increasingly important as the device size reduces to the nanosize. The increased power density in the downscaled device affects the functionality. Hence, it is vital to have a good thermal device material to conduct excessive heat away efficiently so as to maintain its performance. Molecular Dynamics (MD) simulation is a powerful tool that can be used to study the thermal conductivity of materials. Most importantly, it is useful in measuring or observing facts that cannot be realised through experiments. In MD simulations, the thermal conductivity can be computed either using the non-equilibrium or equilibrium techniques. Firstly, a MD simulation is performed to investigate the effect of the Nosé-Hoover thermostat on an equilibrium system. Next, the Nose-Hoover Q-factor is optimized to achieve the minimum possible thermal boundary resistance that exists between the thermostatted and non-thermostatted regions. Then, the direct method (Fourier’s Law) is employed to compute the thermal conductivity of the single-layer graphene system. Secondly, a diamond-graphene-diamond hybrid structure is built for MD simulation to determine the region of interfacial scattering by varying the length of the graphene sheet. Prior to that, we discuss on a devised approach in determining the type of phonon modes in the graphene. For the future tasks, it is interesting to find out the scattering dimension in the graphene of the hybrid structure. Next, further investigation can be carried out to study on how the scattering will affect the graphene thermal conductivity in the hybrid structure.