2D BeP2 monolayer: investigation of electronic and optical properties by driven modulated strain.

Shivam Kansara,Yogesh Sonvane,Sanjeev K Gupta,P N Gajjar

doi:10.1039/d0ra03599h

Abstract

Recently, the two-dimensional (2D) material beryllium diphosphide (BeP2) has attracted significant attention for potential device applications due to its Dirac semimetal state, dynamic and thermal stability, and high carrier mobility. In this work, we investigated its electronic and optical properties under biaxial Lagrangian strain using density functional theory (DFT). Electronic band gaps and effective charge carrier mass were highly sensitive to the Lagrangian strain of BeP2 monolayer. The bandgaps of BeP2 varied from 0 eV to 0.30 eV for 2% to 8% strain, where the strain range is based on the final stable condition of the system. The absorption spectra for the dielectric properties show the highest absorption peaks in the infrared (IR) region. These abundant strain-dependent studies of the BeP2 monolayer provide guidelines for its application in infrared sensors and devices.

Highlights

Strain effects in systems are considered to be highly sensitive effective and convenient tools for their tuning electronic, transport, and optical properties.[1,2,3,4,5,6] The applied strain effects can be interpreted as an elastic eld applied to materials, which modi es the geometrical structure of their crystals due to the interaction between the elastic eld and crystalline eld, in uencing the electronic band structure,[7] and nally tuning the physical,[8] chemical and catalytic properties[9] of materials
As a universal structure, the 2D BeP2 material with Dirac cones found precisely at the Fermi level,[13] high carrier mobility and novel strain-tunable Dirac semimetal state of ultrathin BeP2 can be altered by strain
We have carried out ab initio density functional theory (DFT) calculations, which were implemented using the Vienna Ab initio Simulation Package (VASP).[37,38]

Summary

Introduction

Strain effects in systems (metal, semiconductor, and insulator) are considered to be highly sensitive effective and convenient tools for their tuning electronic, transport, and optical properties.[1,2,3,4,5,6] The applied strain effects can be interpreted as an elastic eld applied to materials, which modi es the geometrical structure of their crystals due to the interaction between the elastic eld and crystalline eld, in uencing the electronic band structure,[7] and nally tuning the physical,[8] chemical and catalytic properties[9] of materials These tools are especially reasonable for the design of two-dimensional (2D) crystals because their low-dimensional structure can sustain much larger strain compared to bulk crystals.[10,11] For example, the black phosphorus (BP) monolayer has been strained up to a noteworthy value of 30% without any dislocation or plastic deformation in its crystal structure,[12] giving a wide range to tune its mechanical and electronic properties.[1] Besides, as a universal structure, the 2D BeP2 material with Dirac cones found precisely at the Fermi level,[13] high carrier mobility and novel strain-tunable Dirac semimetal state of ultrathin BeP2 can be altered by strain.

Methods

Results

Conclusion