Edge conductivity in PtSe$_2$ nanostructures
This addresses the challenge of optimizing nanoelectromechanical sensing and photodetection in PtSe2 for semiconductor applications, but it is incremental as it builds on known material properties and computational methods.
The study tackled the problem of understanding electrical conductivity in polycrystalline PtSe2 nanostructures by modeling ribbons, surfaces, nanoflakes, and nanoplatelets with lateral widths of 5 to 15 nm, finding that electrical conductivity is localized on the edges for sizes below 10 nm, suggesting transport channels in thin films might be dominated by edge networks.
PtSe$_2$ is a promising 2D material for nanoelectromechanical sensing and photodetection in the infrared regime. One of its most compelling features is the facile synthesis at temperatures below 500 °C, which is compatible with current back-end-of-line semiconductor processing. However, this process generates polycrystalline thin films with nanoflake-like domains of 5 to 100 nm size. To investigate the lateral quantum confinement effect in this size regime, we train a deep neural network to obtain an interatomic potential at DFT accuracy and use that to model ribbons, surfaces, nanoflakes, and nanoplatelets of PtSe$_2$ with lateral widths between 5 to 15 nm. We determine which edge terminations are the most stable and find evidence that the electrical conductivity is localized on the edges for lateral sizes below 10 nm. This suggests that the transport channels in thin films of PtSe$_2$ might be dominated by networks of edges, instead of transport through the layers themselves.