The structural, electronic, and optical properties of hydrofluorinated germanene (GeH1-xFx): a first-principles study.

V Kumar,Anita Sinha,R Santosh,J Kumar

doi:10.1007/s00894-021-04741-0

Abstract

The structural, electronic, and optical properties of hydrofluorinated germanene have been studied with different occupancy ratios of fluorine and hydrogen. The hybridization of H-1s and Ge-4p orbitals in hydrogenated germanene and F-2p and Ge-4p orbitals in fluorinated germanene plays a significant role in creating an energy bandgap. The binding energy and phonon calculations confirm the stability of hydrofluorinated germanene decreases with the increase of the F to H ratio. The value of the energy bandgap decreased by increasing the ratio of F and H. The optical properties have been studied in the energy range of 0-25eV. Six essential parameters such as energy bandgap (Eg), binding energy (Eb), dielectric constant ε(0), refractive index n(0), plasmon energy (ћωp), and heat capacity (Cp) have been calculated for different occupancies of H and F in hydrofluorinated germanene for the first time. The calculated values of structural parameters agree well with the reported values.

Highlights

In recent years, much attention has been given to the study of graphene, silicene, and germanene due to their exceptional properties such as linear dispersing energy bands, mass-less Dirac Fermions behavior of electrons, quantum Hall-effect, high electron mobility, etc. [1,2,3,4,5]
The calculation of structural parameters has been started with the hydrogenated germanene in chair (C) -configuration
The values of energy bandgap (Eg) for fully hydrogenated and fluorinated germanene are in good agreement with known values

Summary

Introduction

Much attention has been given to the study of graphene, silicene, and germanene due to their exceptional properties such as linear dispersing energy bands, mass-less Dirac Fermions behavior of electrons, quantum Hall-effect, high electron mobility, etc. [1,2,3,4,5]. Several DFT calculations confirm that hydrogenated germanene shows a large bandgap compared to fluorinated germanene [14, 22,23,24]. The authors have recently studied several properties of functionalized graphene, silicene, and germanene using first-principle calculations [27,28,29].

Results

Conclusion