Quantum transport simulation is used to examine the properties of graphene nanoribbons in geometries that can be fabricated through bottom-up chemical synthesis. The chevron graphene nanoribbon is shown to have an electronic structure analogous to traditional semiconductor superlattices. It is shown how this property could be utilized to create a new type of device, which exhibits both negative differential resistance and steep-slope (< 60 mV/decade) switching for low-power electronics applications. We discuss BerkeleyNano3D, a new quantum transport simulator based on the non-equilibrium Green’s function (NEGF) formalism, which is capable of efficient three-dimensional device simulation on large computing clusters.
Finally, the phenomenon of ferroelectric negative capacitance is examined through the lens of phase-field simulations based on the time-dependent Ginzburg-Landau equation. This phenomenon has been previously predicted as a means to enable energy-efficient steep-slope device with minimal modification to existing transistor processes. Simulation results from three-dimensional phase-field modeling provide new insight into the underlying mechanisms for negative capacitance and give far better agreement with experiment than previously studied single domain models.