Electrostatic Imaging of Encapsulated Graphene
arXiv:1911.04114 · doi:10.1088/2053-1583/ab254e
Abstract
Devices made from two dimensional materials such as graphene and transition metal dichalcogenides exhibit remarkable electronic properties of interest to many subdisciplines of nanoscience. Owing to their 2D nature, their quality is highly susceptible to contamination and degradation when exposed to the ambient environment. Protecting the 2D layers by encapsulation between hexagonal boron nitride layers significantly improves their quality. Locating these samples within the encapsulant and assessing their integrity prior to further processing then becomes challenging. Here we show that conductive scanning probe techniques such as electrostatic force and Kelvin force microscopy makes it possible to visualize the encapsulated layers, their charge environment and local defects including cracks and bubbles on the sub-micrometer scale. Our techniques are employed without requiring electrical contact to the embedded layer, providing valuable feedback on the local electronic quality prior to any device etching or electrode deposition. We show that these measurement modes, which are simple extensions of atomic force microscopy, are perfectly suited for imaging encapsulated conductors and their local charge environments.
12 pages, 7 figures
References in corpus (6)
- Boron nitride substrates for high-quality graphene electronics
- Suspended Graphene: a bridge to the Dirac point
- Micrometer-scale ballistic transport in encapsulated graphene at room temperature
- STM Spectroscopy of ultra-flat graphene on hexagonal boron nitride
- Single Layer Behavior and Its Breakdown in Twisted Graphene Layers
- Multicomponent fractional quantum Hall effect in graphene