Wei XL, Bando Y, Golberg D
. Electron Emission from Individual Graphene Nanoribbons Driven by Internal Electric Field
. Acs Nano [Internet]. 2012;6:705-711. 访问链接Abstract
Electron emission from individual graphene nanoribbons (GNRs) driven by an internal electric field was studied for the first time Inside a high resolution transmission electron microscope equipped with a state-of-art scanning tunneling microscope sample holder with independent twin probes. Electrons were driven out from Individual GNRs under an internal driving voltage of less than 3 V with an emission current increasing exponentially with the driving voltage. The emission characteristics were analyzed by taking Into account monatomic thickness of GNRs. While deviating from the two-dimensional Richardson equation for thermionic emission, they were well described by the recently proposed by us phonon-assisted electron emission model. Different from widely studied field electron emission from graphene edges, electrons were found to be emitted perpendicularly to the atomic graphene surfaces with an emission density as high as 12.7 A/cm(2). The internally driven electron emission is expected to be less sensitive to the microstructures of an emitter as compared to field emission. The low driving voltage, high emission density, and internal field driving character make the regarded electron emission highly promising for electron source applications.
Tang D-M, Ren C-L, Wang M-S, Wei X, Kawamoto N, Liu C, Bando Y, Mitome M, Fukata N, Golberg D
. Mechanical Properties of Si Nanowires as Revealed by in Situ Transmission Electron Microscopy and Molecular Dynamics Simulations
. Nano Letters. 2012;12:1898-1904.
Golberg D, Costa P, Wang MS, Wei XL, Tang DM, Xu Z, Huang Y, Gautam UK, Liu BD, Zeng HB, et al. Nanomaterial Engineering and Property Studies in a Transmission Electron Microscope
. Advanced Materials [Internet]. 2012;24:177-194. 访问链接Abstract
Modern methods of in situ transmission electron microscopy (TEM) allow one to not only manipulate with a nanoscale object at the nanometer-range precision but also to get deep insights into its physical and chemical statuses. Dedicated TEM holders combining the capabilities of a conventional high-resolution TEM instrument and atomic force -, and/or scanning tunneling microscopy probes become the powerful tools in nanomaterials analysis. This progress report highlights the past, present and future of these exciting methods based on the extensive authors endeavors over the last five years. The objects of interest are diverse. They include carbon, boron nitride and other inorganic one- and two-dimensional nanoscale materials, e.g., nanotubes, nanowires and nanosheets. The key point of all experiments discussed is that the mechanical and electrical transport data are acquired on an individual nanostructure level under ultimately high spatial, temporal and energy resolution achievable in TEM, and thus can directly be linked to morphological, structural and chemical peculiarities of a given nanomaterial.