In-Plane Anisotropies of Polarized Raman Response and Electrical Conductivity in Layered Tin Selenide

TL;DR

This study investigates the anisotropic optical and electrical properties of single crystal SnSe nanoplates, revealing strong directional dependence crucial for optimizing thermoelectric and optoelectronic devices.

Contribution

It provides a comprehensive analysis of the anisotropic Raman response and electrical conductivity in SnSe nanostructures, advancing understanding of their directional properties.

Findings

Anomalous anisotropic polarized Raman spectra in SnSe nanoplates

Strong angular dependence of electrical conductivity in SnSe NPs

Insights into anisotropic interactions for device applications

Abstract

The group IV-VI compound SnSe, with an orthorhombic lattice structure, has recently attracted particular interest due to its unexpectedly low thermal conductivity and high power factor, showing great promise for thermoelectric applications. SnSe displays intriguing anisotropic properties due to the puckered low-symmetry in-plane lattice structure. Low-dimensional materials have potential advantages in improving the efficiency of thermoelectric conversion, due to the increased power factor and decreased thermal conductivity. A complete study of the optical and electrical anisotropies of SnSe nanostructures is a necessary prerequisite in taking advantage of the material properties for high performance devices. Here, we synthesize the single crystal SnSe nanoplates (NPs) by chemical vapor deposition. The angular dependence of the polarized Raman spectra of SnSe NPs shows anomalous anisotropic light-mater interaction. The angle-resolved charge transport of the SnSe NPs expresses a strong anisotropic conductivity behavior. These studies elucidate the anisotropic interactions which will be of use for future ultrathin SnSe in electronic, thermoelectric and optoelectronic devices.