1. Center for Functional Nanomaterials Seminar

    "Graphene/Graphite: Schottky Devices and Fundamental Science"

    Presented by Xiaochang Miao, University of Florida, Gainesville

    Thursday, August 1, 2013, 10 am
    Bldg. 735 — Conf Rm B

    Hosted by: Chuck Black

    Graphene has drawn intensive research attention both to discover the underlying fundamental science and to exploit its great potential in novel electronic device applications. In the first half of this talk, I will describe experiments that demonstrate the formation of Schottky barriers at the interface of graphene and a surprisingly wide range of semiconductors such as Si, GaN, GaAs and 4H-SiC. Thanks to graphene's high optical transmittance, the graphene/n-Si Schottky diodes can be used for photovoltaic (PV) applications. Moreover, polymer doping of such devices achieves record-high power conversion efficiencies (8.6%) in all graphene-based PV cells. Complementary to the device applications, in the latter half of this talk, I will discuss fundamental physical studies, including: 1) the strain induced suppression of weak-localization in CVD-grown grapheme, and 2) the extinction of ferromagnetism (FM) in highly oriented pyrolytic graphite after thermal annealing. The suppression of weak-localization is due to the dramatically reduced intervalley scattering, while the unusual FM is related to the lattice imperfection. These results are in good agreement with previous studies.