Illustrious influence of amino acid L-threonine (LT) on structural and optical insights of Zinc Thiourea Sulphate (ZTS) crystal

Abstract

Mentioned communication explores the modification in properties of Zinc Thiourea Sulphate (ZTS) crystal due to L-Threonine (LT) addition. Superior quality LT-doped ZTS crystal with 0.5 M% concentration of LT was grown by the slow evaporation solution growth technique. Powder X-ray diffraction technique was applied to study the cell parameters which confirmed orthorhombic crystal structure of both pure and LT-ZTS crystal with slight variation in cell parameters. Shimatzu make spectrophotometer confirmed the UV-Visible spectral analysis in the range of 200–900 nm which affirmed the 94% transmittance, enhanced bandgap value (4.72 eV), lower cut-off value (246 nm) and lower optical constants viz. extinction coefficient, polarizability, refractive index, and reflectance of LT-ZTS crystal. The higher second harmonic generation (SHG) efficiency of LT-doped ZTS was pointed by Kurtz Perry powder method (3.06 times of pure ZTS crystal and 3.62 times of KDP crystal) using Nd: YAG laser. The colour centered emission and electronic purity of parent and doped ZTS crystals were examined which resulted in the violet emission in visible region for both pure and LT-ZTS crystals. Z-scan technique is used to identify the Kerr lensing nonlinearity in pure and LT-doped ZTS crystal. Close aperture Z-scan curve demonstrated negative refraction nonlinearity (self-defocusing nature) for pure and positive refraction nonlinearity (self-focusing nature) for LT-ZTS crystal. Calculated value of refraction nonlinearity n2 is −2.2 × 10[Formula: see text] cm2/W for pure ZTS and [Formula: see text]4.99 × 10[Formula: see text] cm2/W for LT-ZTS crystal. Open aperture Z-scan showed reverse saturable absorption effect (RSA) in pure ZTS and saturable absorption effect (SA) in LT-ZTS crystal. The [Formula: see text] value is 2.85 × 10[Formula: see text] cm/W for pure ZTS and 3.92 × 10[Formula: see text] cm/W for LT-ZTS crystal. The [Formula: see text]3 of ZTS crystal is 6.133 × 10[Formula: see text] cm/W and 1.655 × 10[Formula: see text] cm2/W for LT-ZTS crystal. The transition in TONLO parameters is observed due to doping of LT in ZTS. The obtained parameters indicated the superiority of LT-ZTS for application in distinct laser stabilization systems, UV shelter and NLO applications.