Fully Anisotropic Solution of the Three Dimensional Boltzmann Transport Equation

The development of accurate modeling techniques for nanoscale thermal transport is an active area of research. Modern day nanoscale devices have length scales of tens of nanometers and are prone to overheating, which reduces device performance and lifetime. Therefore, accurate temperature profiles are needed to predict the reliability of nanoscale devices. The majority of models that appear in the literature obtain temperature profiles through the solution of the Boltzmann transport equation (BTE). These models often make simplifying assumptions about the nature of the quantized energy carriers (phonons). Additionally, most previous work has focused on simulation of planar two dimensional structures. This thesis presents a method which captures the full anisotropy of the Brillouin zone within a three dimensional solution to the BTE. The anisotropy of the Brillouin zone is captured by solving the BTE for all vibrational modes allowed by the Born Von-Karman boundary conditions.

Wetting of Graphene

Graphene, a remarkable 2D material, has attracted immense attention for its unique physical properties that make it ideal for a myriad of applications from electronics to biology. Fundamental to many such applications is the interaction of graphene with water, necessitating an understanding of wetting of graphene. Here, molecular dynamics simulations have been employed to understand two fundamental issues of water drop wetting on graphene: (a) the dynamics of graphene wetting and (b) wetting of graphene nanostructures. The first problem unravels that the wetting dynamics of nanodrops on graphene are exactly the same as on standard, non-2D (or non-layered) solids – this is an extremely important finding given the significant difference in the wetting statics of graphene with respect to standard solids stemming from graphene’s wetting translucency effect. This same effect, as shown in the second problem, interplays with roughness introduced by nanostructures to trigger graphene superhydrophobicity following a hitherto unknown route.