Growth mechanism and physicochemical properties of L-threonine silver nitrate (LTSN) single crystal for frequency doubling and optical limiting applications

A semi-organic nonlinear optical crystal of L-threonine silver nitrate (LTSN) was successfully cultivated using a slow evaporation solution growth method at ambient temperature. The grown LTSN crystals were thoroughly characterized through various methods like single crystal and powder X-ray diffraction (XRD), UV–Vis-NIR spectroscopy, FTIR, thermal analysis, microhardness, dielectric measurements, laser damage threshold (LTD), second harmonic generation (SHG), Third order generation, and etching analysis. XRD results reveal that the LTSN crystallizes in a monoclinic system with a non-centrosymmetric space group of P2 ₁ . FT-IR spectroscopy confirmed the presence of all expected functional groups. Remarkable thermal stability up to 210°C is analyzed by thermogravimetric and differential thermal (TG/DT) analysis. A deep mechanical analysis was carried out to understand the complete mechanical behavior of the grown material. The UV–Vis-NIR study showed excellent optical transparency in the entire visible region, with a lower cut-off wavelength of 285.5 nm and an optical band gap E _g = 4.33 eV. In addition, optical parameters like extinction coefficient, reflectance, and linear refractive index are also calculated for the cultivated material. The laser damage threshold analysis was carried out on the surface of the cultivated material, and it was found to be 5.86 GW/cm ² . The SHG efficiency of LTSN crystal reveals an efficiency 4.38 times higher than standard. The investigation of third-order nonlinear optical characteristics and optical limiting behavior was performed utilizing the Z-scan method with a continuous wave (CW) laser operated at 532 nm. The findings indicated significant χ ⁽³⁾ values of 2.889×10 ^− 08 esu, along with an optical limiting threshold noted at 2.427 × 10 ³ Wcm ^− 2 . The dielectric analysis was carried out for the grown LTSN crystal. The growth mechanism and quality of the grown crystal were analysed by etching analysis. In summary, the results of these studies suggest that the synthesized L-threonine silver nitrate-derived material possesses potential for use in optical limiting, switching, and optoelectronic applications.