Tailoring the Dimensionality of Tellurium Nanostructures via Vapor Transport Growth

TL;DR

This paper demonstrates controlled vapor deposition methods to synthesize tellurium nanostructures of various dimensions, including pillar-like, pennette-like, and ultrathin 2D tellurene, with potential applications in electronics and optoelectronics.

Contribution

It introduces a scalable vapor deposition approach to tailor tellurium nanostructure dimensionality, including the growth of ultrathin 2D tellurene without additives.

Findings

Salt additives enhance pillar dimensionality and large planar grains.

Optimized growth kinetics enables monolayer tellurene synthesis.

Characterization confirms high surface quality and desirable physical properties.

Abstract

The interest in tellurium nanostructures is on the rise due to their outstanding physical properties including high carrier mobility, anisotropic charge conduction, photoconductivity, thermoelectricity, and piezoelectricity. Applications in related technologies require tailoring the synthesis of tellurium from its preferred vertical growth toward the lateral growth. Here, the synthesis of pillar-like and pennette-like structures of tellurium through a powder vapor deposition technique has been discussed. It has been shown that exploiting salt additives such as NaCl in vapor deposition technique can enhance tellurium pillar dimensionality toward large planar grains. Further, we report on the synthesis of hexagonal ultrathin tellurium nanoflakes, namely tellurene, from few-layer to monolayer thickness by optimizing the growth kinetics without the usage of any additives. In addition, we explore the surface quality and physical properties of as-grown two-dimensional (2D) tellurium, using a variety of characterization techniques, including Raman spectroscopy, scanning electron microscopy, atomic force microscopy, and Kelvin probe force microscopy. This study provides a pivotal scheme for enabling scalable 2D tellurium integration in numerous potential applications for electronics and optoelectronic devices.