Ashley L. Gibb

Atomic Resolution Imaging of Grain Boundary Defects in Monolayer Chemical Vapor Deposition-Grown Hexagonal Boron Nitride

Grain boundaries are observed and characterized in chemical vapor deposition-grown sheets of hexagonal boron nitride (h-BN) via ultra-high-resolution transmission electron microscopy at elevated temperature. Five- and seven-fold defects are readily observed along the grain boundary. Dynamics of strained regions and grain boundary defects are resolved. The defect structures and the resulting out-of-plane warping are consistent with recent theoretical model predictions for grain boundaries in h-BN.

Longitudinal Splitting of Boron Nitride Nanotubes for the Facile Synthesis of High Quality Boron Nitride Nanoribbons

Boron nitride nanoribbons (BNNRs), the boron nitride structural equivalent of graphene nanoribbons (GNRs), are predicted to possess unique electronic and magnetic properties. We report the synthesis of BNNRs through the potassium-intercalation-induced longitudinal splitting of boron nitride nanotubes (BNNTs). This facile, scalable synthesis results in narrow (down to 20 nm), few sheet (typically 2-10), high crystallinity BNNRs with very uniform widths. The BNNRs are at least 1 μm in length with minimal defects within the ribbon plane and along the ribbon edges.

Metal insulator semiconductor solar cell devices based on a Cu2O substrate utilizing h-BN as an insulating and passivating layer

We demonstrate cuprous oxide (Cu2O) based metal insulator semiconductor Schottky (MIS-Schottky) solar cells with efficiency exceeding 3%. A unique direct growth technique is employed in the fabrication, and hexagonal boron nitride (h-BN) serves simultaneously as a passivation and insulation layer on the active Cu2O layer. The devices are the most efficient of any Cu2O based MIS-Schottky solar cells reported to date.

In Situ High Temperature Atomic Resolution Transmission Electron Microscopy of 2D Nanomaterials

1 Department of Chemistry, University of California Berkeley, Berkeley, CA USA 2 Department of Physics, University of California Berkeley, Berkeley, CA USA 3 Materials Science Division, Lawrence Berkeley National Lab, Berkeley CA USA 4 National Center for Electron Microscopy, Berkeley, CA USA 5 Department of Materials Science, Pennsylvania State University, State College, PA USA 6 Department of Physics, Peking University, Beijing, China