Optoelectronic, thermoelectric, and EFG of atomic nuclei of trityl-functionalized fullerene C60 using GGA and mBJ approximations

Abstract

Fullerene C₆₀ with high electron mobility, light absorption, and electron-accepting capability is used in the new industries and its functionalization help to improve the optoelectronic and thermoelectric of C₆₀. In this study, we have calculated the structural, optoelectronic, and thermoelectric properties of trityl-functionalized C₆₀ (C₈₁H₁₉N complex $\equiv$ C₆₀- C₂H₄N- (C₆H₅)₃C⁻) using the first-principles calculations. The exchange-correlation energies are calculated by the Generalized Gradient Approximation (GGA) and the modified Becke-Johnson (mBJ) potential. The results show that C₈₁H₁₉N has an indirect bandgap of 1.17 and 1.32 eV by GGA and mBJ approximations, respectively. The optical band gap decreases with functionalizing the C₆₀ and a redshift is observed in the absorption spectra. It is found that N atoms play a key role in the physical properties of the C₈₁H₁₉N. The calculated plasmon energy and negative dielectric function values in some optical areas show that it can be used in optical devices. In comparison with GGA, obtained results by mBJ are the more accurate. The semi-classical Boltzmann transport theory is used to study the thermoelectric properties of C₈₁H₁₉N.

The calculated figure of merit ZT show that it also suitable for using in the renewable energy sources with high efficiency. Obtained results by the Electric Field Gradients (EFGs) show that the nature of charge density around C changes from a prolate to an oblate shape.