Growth and characterization of β-anilinium 4-hydroxybenzenesulfonate single crystals for promising optical applications

This article presents a detailed study on the growth and characterization of β-anilinium 4-hydroxybenzenesulfonate (BA4BS) single crystals, focusing on their potential applications in nonlinear optics. The research involves a comprehensive experimental investigation, including single crystal X-ray diffraction (SCXRD), powder X-ray diffraction (PXRD), UV–Vis spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TG–DTA), photoconductivity measurements, dielectric studies, and Z-scan analysis. Theoretical studies such as frontier molecular orbital (FMO) analysis, Hirshfeld surface analysis, and topological analyses are also conducted to complement the experimental data. The study reveals that BA4BS crystallizes in the centrosymmetric P2₁/c space group, exhibiting a pronounced third-order nonlinear optical response. The material demonstrates a high optical band gap of 3.819 eV, indicating its suitability for visible and ultraviolet applications. Thermal analysis shows remarkable stability up to 151°C, making it viable for device fabrication. The negative photoconductive behaviour observed highlights its potential for advanced photodetection applications. Dielectric properties and solid-state parameters are systematically analyzed, providing critical insights into the material's electrical characteristics. The Z-scan experiments confirm strong nonlinear optical behaviours, with a third-order nonlinear optical susceptibility of 2.555×10⁻⁶ esu. Overall, the study positions BA4BS as a promising candidate for advanced photonic and nonlinear optical applications, offering a comprehensive understanding of its structural, thermal, optical, and electrical properties.