Optoelectronic, luminescence, and nonlinear properties of a non-centrosymmetric Cd(II)-based complex

Abstract

Single crystals of 1,2-diammoniumcyclohexane tetrabromocadmate(II) monohydrate, abbreviated as CdDACH, have been obtained by the slow evaporation solution growth method using methanol as solvent. Single-crystal X-ray diffraction analysis has been utilized to compute the unit cell parameters of the CdDACH crystal. The molecular structure has been analyzed by FTIR, FT-Raman, and ATG/DSC measurements. The electronic behavior has been determined by DFT methods at the B3LYP/LANL2DZ level. The UV/Visible spectrum indicates a direct band gap (4.88 eV) and a low cut-off wavelength (250 nm) for the crystal. Photoluminescence measurement of CdDACH yielded a broad peak at 506 nm with a width at half-maximum of 94 nm. Electrical and optical parameters, namely refractive index (n), extinction coefficient (k), electrical conductivity (σe), and optical conductivity (σopt), have been derived by means of diffuse-reflectance spectroscopy. With a high optical conductivity of 1010 s−1, the suitability of the photo-response of the crystal for use in devices that perform information processing has been established. The first hyperpolarizability (β) and second hyperpolarizability (γ) of the material have been theoretically investigated through TD-DFT calculations. The third-order susceptibility χ(3) of CdDACH crystals, estimated by the Lorentz approximation, was found to be of the order of 10−4 esu. The obtained results indicate that CdDACH may be adopted for future second and third harmonic generation applications.