Layer Dependence of Dielectric Response and Water-Enhanced Ambient Degradation of Highly Anisotropic Black As.
Hwanhui YunSupriya GhoshPrafful GolaniSteven J KoesterK Andre MkhoyanPublished in: ACS nano (2020)
Black arsenic (BAs) is a van der Waals layered material with a puckered honeycomb structure and has received increased interest due to its anisotropic properties and promising performance in devices. Here, crystalline structure, thickness-dependent dielectric responses, and ambient stability of BAs nanosheets are investigated using scanning transmission electron microscopy (STEM) imaging and spectroscopy. Atomic-resolution high-angle annular dark-field (HAADF)-STEM images directly visualize the three-dimensional structure and evaluate the degree of anisotropy. STEM-electron energy loss spectroscopy is used to measure the dielectric response of BAs as a function of the number of layers. Finally, BAs degradation under different ambient environments is studied, highlighting high sensitivity to moisture in the air.
Keyphrases
- electron microscopy
- high resolution
- air pollution
- particulate matter
- single molecule
- solid state
- optical coherence tomography
- reduced graphene oxide
- drinking water
- highly efficient
- convolutional neural network
- room temperature
- heavy metals
- atomic force microscopy
- gold nanoparticles
- metal organic framework
- fluorescence imaging