Two-Dimensional Graphene/h-BN Heterostructures for Nanoelectronics

posted Jun 14, 2013, 8:34 AM by Timothy Fisher   [ updated Jun 24, 2013, 7:40 PM by Nick Glavin ]

Student: Nicholas Glavin

Faculty: Tim Fisher

Sponsor: Air Force Research Laboratory

Summary:  Atomically thin two-dimensional materials including graphene and hexagonal-boron nitride are attracting significant interest in the research community due to their intrinsic optical and electronic properties.  In particular, graphene, a two dimensional atomically thin sheet of sp2 bonded carbon atoms, has been shown to exhibit ambipolar transport and the highest electron mobilities of any material to date.  However, the lack of a significant band gap limits graphene for use in transistor applications.  Hexagonal-BN sheets stacked on graphene as well as h-BN domains substituted within the graphene lattice have been investigated as two potential techniques to engineer and control the band structure without significantly altering the mobility. Ideally, transistors fabricated from a bottom-up growth and/or controlled levels of BN substitution could lead to precise control of film thickness and quality, the reduction of interfacial electron scattering upon stacking, enable for better scale-up potential in future devices, and produce a significant band gap for transistor functionality.  This work focuses on growth and characterization of stackable and substituted graphene/h-BN heterostructures by means of Pulsed Laser Deposition (PLD), Molecular Beam Epitaxy (MBE), and microwave annealing techniques, with a focus on the understanding of electron and phonon transport at the nanoscale domain.