Surface functionalization of the honeycomb structure of zinc antimonide (ZnSb) monolayer: A first-Principles study

Abstract

Structural, electronic, optic and vibrational properties of Zinc antimonide (ZnSb) monolayers and their functionalized (semifluorinated and fully chlorinated) structures are investigated by means of the first-principles calculations. The phonon dispersion curves reveal the presence of imaginary frequencies and thus confirm the dynamical instability of ZnSb monolayer. The calculated electronic band structure corroborates the metallic character with fully-relativistic calculations. Moreover, we analyze the surface functionalization effect on the structural, vibrational, and electronic properties of the pristine ZnSb monolayer. The semi-fluorinated and fully-chlorinated ZnSb monolayers are shown to be dynamically stable in contrast to the ZnSb monolayer. At the same time, semi-fluorination and fully-chlorination of ZnSb monolayer could effectively modulate the metallic electronic properties of pristine ZnSb. In addition, a magnetic metal to a nonmagnetic semiconductor transition with a band gap of 1 eV is achieved via fluorination, whereas a transition to a semiconducting state with 1.4 eV band gap is found via chlorination of the ZnSb monolayer. According to the optical properties analysis, the first absorption peaks of the fluorinated-and chlorinated-ZnSb monolayers along the in-plane polarization are placed in the infrared range of spectrum, while they are in the middle ultraviolet for the out-of-plane polarization. Interestingly, the optically anisotropic behavior of these novel monolayers along the in-plane polarizations is highly desirable for design of polarization-sensitive photodetectors. The results of the calculations clearly proved that the tunable electronic properties of the ZnSb monolayer can be realized by chemical functionalization for application in the next generation nanoelectronic devices.

Ultrahigh anisotropic carrier mobility in ZnSb monolayers functionalized with halogen atoms

“…It exhibits a nearly direct band gap of 0.38 eV with the conduction band minimum (CBM) at the Γ point and the valence band maximum (VBM) slightly away from the Γ point. This gap value is smaller than 0.5 eV reported by Bafekry et al , 41 which could be due to the consideration of spin–orbit coupling. The orbital-projected density of states show that the conduction band states near Fermi level are mainly composed of the Sb-p and Cl-p orbitals, indicating a strong orbital interaction.…”

Tunable electronic and magnetic properties of MoSi2N4 monolayer via vacancy defects, atomic adsorption and atomic doping

“…Defects can play different roles such as carrier donors, scattering, trapping, and recombination centers [36][37][38][39]. Furthermore, the properties of the 2DMs can be tailored via defect engineering [40][41][42][43].…”

First-Principles Study of Mn-Doped and Nb-Doped CsPbCl3 Monolayers as an Absorber Layer in Solar Cells

“…But, DFT study of the CsPbCl 3 monolayer showed that it consists of a wide bandgap which limits its solar cell applications; hence, we thought of opting for some alternative technique which in turn would enhance the properties of the monolayer and further our cause. For modifying various properties of the monolayer, techniques such as doping, strain engineering, applying an electric field, and many other methods are being practiced. − Here we opted for the technique of adding impurities (Mn and Nb) into our monolayer which might lead to certain modifications in its electronic properties. Even though Mn doping is highly studied, ,− the reason behind considering Mn as dopant is its ability to induce optical properties in the doped host semiconductor nanocrystals.…”