# Negative differential conductance effect and electrical anisotropy of 2D ZrB2 monolayers

## TL;DR

This study reveals that 2D ZrB2 monolayers exhibit electrical anisotropy and negative differential conductance, with potential applications in nanoscale electronic devices, as shown through theoretical calculations of their transport properties.

## Contribution

It is the first detailed theoretical analysis of the electrical transport and NDC effect in 2D ZrB2 monolayers along different crystallographic directions.

## Key findings

- Electrical transport is similar along zigzag and armchair directions at low bias.
- High bias induces electrical anisotropy and divergence in I-V curves.
- Both ZrB2 orientations exhibit negative differential conductance.

## Abstract

Two-dimensional (2D) metal-diboride ZrB2 monolayers was predicted theoretically as a stable new electronic material [A. Lopez-Bezanilla, Phys. Rev. Mater., 2018, 2, 011002 (R)]. Here, we investigate its electronic transport properties along the zigzag (z-ZrB2) and armchair (a-ZrB2) directions, using the density functional theory and non-equilibrium Green's function methods. Under low biases, the 2D ZrB2 shows a similar electrical transport along zigzag and armchair directions as electric current propagates mostly via the metallic Zr-Zr bonds. However, it shows an electrical anistropy under high biases, and its I-V curves along zigzag and armchair directions diverge as the bias voltage is higher than 1.4 V, as more directional B-B transmission channels are opened. Importantly, both z-ZrB2 and a-ZrB2 show a pronounced negative differential conductance (NDC) effect and hence they can be promising for the use in NDC-based nanodevices.

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Source: https://tomesphere.com/paper/1812.01123