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 ¼ 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 mol ) 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 ðςÞ, 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.

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In this study, the RHF and B3LYP methods with cc-pVDZ basis set have been used to investigate the non-linear optical (NLO), electronic, optoelectronic and thermodynamic properties of bis (ethylenedithio) tetrathiafulvalene and its chlorine and bromine derivatives. The results show that the undoped molecule denoted BEDT-TTF or ET (Eg =3.88 eV) and its derivatives are semi-conductors materials. However, one of them, Br4ET molecule doped with bromine, considerably improves its energy band gap Eg =2.88 eV is less than 3 eV, which makes more ineresting electronic properties. Some parameters such as dipole moment, average polarizability and first order hyperpolarizability have been calculated. In order to compare the results of molecules and with those of Urea, we have computed first molecular hyperpolarizability ꞵ, doped structures (ET chlorinated and brominated) find applications in telecommunication, in modern communication technology and data storage as NLO active materials. Moreover, the chemical potential, ionization potential, electron affinity, electronegativity, global hardness, softness, refractive index, dielectric constant, electric field and electric susceptibility have also been determined. The results show that there is a good electronic transfer within the doped molecules and could have potential applications as semiconductor components, photovoltaic and photonic devices. Finally thermodynamic properties have been also computed.