High throughput differential phase contrast (DPC) imaging of Si-MoS2 core-shell structure

Gatan instrument used

The Stela^® hybrid-pixel camera, utilizing DECTRIS technology, enables a high signal-to-noise ratio (via electron counting) high dynamic range diffraction imaging at fast frame rates (>16,000 fps). STEMx^® system hardware synchronizes the scanning probe to the detector frame rate, enabling high throughput 4D scanning transmission electron microscopy (4D STEM) data acquisition and processing within the DigitalMicrograph^® software.

Background

Transition metal dichalcogenide (TMD) core-shells are very recently emerged structures with potential applications in optoelectronics, biomedicine, energy, and sensing^{[1, 2]}. In such materials, a multilayer TMD shell encapsulates a nano-sized core, presenting the opportunity to engineer and design the shell defects/properties/functionality via manipulating the underlying core structure. The core shell structure also provides a natural platform to leverage built-in strain to tune electronic and chemical properties. DPC is applied to elucidate the in-built electric field distribution across the core-shell structure.