Monolayer 2D semiconducting tellurides for high-mobility electronics

TL;DR

This paper introduces a new family of monolayer 2D tellurides with direct band gaps and ultra-high carrier mobility, promising for high-speed electronics and optoelectronic applications.

Contribution

The study identifies and characterizes a novel family of monolayer 2D tellurides with desirable electronic properties using first principles calculations.

Findings

Direct band gaps from 1.0 to 1.31 eV suitable for photonics

Anisotropic in-plane transport behavior observed

Predicted ultra-high carrier mobility

Abstract

Discovery and design of two-dimensional (2D) materials with suitable band gaps and high carrier mobility is of vital importance for photonics, optoelectronics, and high-speed electronics. In this work, based on first principles calculations using density functional theory (DFT) with PBE and HSE functionals, we introduce a family of monolayer isostructural semiconducting tellurides M2N2Te8, with M = {Ti, Zr, Hf} and N= {Si, Ge}. These compounds have been identified to possess direct band gaps from 1.0 eV to 1.31 eV, which are well suited for photonics and optoelectronics applications. Additionally, anisotropic in-plane transport behavior is observed and small electron and hole (0.11 - 0.15 me) effective masses are identified along the dominant transport direction. Ultra-high carrier mobility is predicted for this family of 2D compounds which host great promise for potential applications in high-speed electronic devices. Detailed analysis of electronic structures reveals the origins of the promising properties of this unique class of 2D telluride materials.