Ab initio investigation of nonlinear optical, electronic, and thermodynamic properties of BEDT-TTF molecule: doping with boron

G F Olinga Mbala; M T Ottou Abe; Z Ntieche; G W Ejuh; J M B Ndjaka

doi:10.1016/j.heliyon.2021.e07461

Ab initio investigation of nonlinear optical, electronic, and thermodynamic properties of BEDT-TTF molecule: doping with boron

Heliyon. 2021 Jul 3;7(7):e07461. doi: 10.1016/j.heliyon.2021.e07461. eCollection 2021 Jul.

Authors

G F Olinga Mbala¹, M T Ottou Abe^{1

2}, Z Ntieche^{1

3}, G W Ejuh^{4

5}, J M B Ndjaka¹

Affiliations

¹ Faculty of Science, Department of Physics, University of Yaoundé I, P.M.B 812, Yaoundé, Cameroon.
² Laboratory of Pharmaceutical Technology, Institute of Medical Research and Medicinal, Plants Studies, P.O Box 6163, Yaounde, Cameroon.
³ Local Materials Promotion Authority (MIPROMALO), P.O. Box 2396, Yaounde, Cameroon.
⁴ Department of Electrical and Electronic Engineering, National Higher Polytechnic Institute, University of Bamenda, P. O. Box 39, Bambili, Cameroon.
⁵ Department of General and Scientific Studies, IUT-FV Bandjoun, University of Dschang, P.M.B 134, Bandjoun, Cameroon.

Abstract

In this study, the RHF, B3LYP and wB97XD methods with cc-pVDZ basis set have been used to investigate the influence of carbon atoms substitution with boron atoms on the non-linear optical, electronic, optoelectronic and thermodynamic properties of BEDT-TTF ( $C_{10} H_{8} S_{8}$ ). The results show that the undoped molecule denoted BEDT-TTF or ET (Eg = 3.88 eV) and its derivatives are semi-conductors materials. However, doping $C_{10} H_{8} S_{8}$ with both 3B and 2B, creating a strong donor-acceptor system and considerably improves its energies gap (Egap). The Eg values of these doped molecules are between 2.2 and 2.39 eV less than 3 eV, which makes more interesting electronic properties. The nonlinear optical parameters such as dipole moment (μ), average polarizability ˂α˃ and first-order hyperpolarizability ( $β_{m o l}$ ) have been calculated and compared with the corresponding values of Urea used as prototypical material to study the NLO properties of the compound. These values obtained indicate that these materials exhibit good nonlinear optical properties. Moreover, we have also computed the chemical softness $(ς)$ , ionization potential (IP), electron affinity (AE), global hardness (η), refractive index (n), dielectric constant (ε), electric field (E) and electric susceptibility (χ), total electronic energy (Eo), enthalpy H, entropy S. These results indicate that these new materials doped with boron are promising candidates for the construction of optoelectronics and photonic devices.

Keywords: BEDT-TTF; Doping; Hyperpolarizability; NBO; Nonlinear optical properties; Optoelectronic.