Correlating Nanocrystalline Structure with Electronic Properties in 2D Platinum Diselenide

TL;DR

This study explores how the nanocrystalline structure of thermally grown PtSe₂ thin films influences their electronic and piezoresistive properties, providing insights for optimizing 2D material-based devices.

Contribution

It establishes a correlation between nanocrystalline structure variations and electronic/piezoresistive properties in PtSe₂ films, aiding targeted material optimization.

Findings

Crystallite size affects sheet resistivity.

Orientation influences charge carrier mobility.

Structural variations correlate with electronic properties.

Abstract

Platinum diselenide (PtSe${_2}$) is a two-dimensional (2D) material with outstanding electronic and piezoresistive properties. The material can be grown at low temperatures in a scalable manner which makes it extremely appealing for many potential electronics, photonics, and sensing applications. Here, we investigate the nanocrystalline structure of different PtSe${_2}$ thin films grown by thermally assisted conversion (TAC) and correlate them with their electronic and piezoresistive properties. We use scanning transmission electron microscopy for structural analysis, X-ray photoelectron spectroscopy (XPS) for chemical analysis, and Raman spectroscopy for phase identification. Electronic devices are fabricated using transferred PtSe${_2}$ films for electrical characterization and piezoresistive gauge factor measurements. The variations of crystallite size and their orientations are found to have a strong correlation with the electronic and piezoresistive properties of the films, especially the sheet resistivity and the effective charge carrier mobility. Our findings may pave the way for tuning and optimizing the properties of TAC-grown PtSe${_2}$ towards numerous applications.