Enhancing the SHG effect of zinc chloride-doped DAST single crystals: new potential materials for nonlinear optical device applications

The ionic organic salts of 4-dimethylamino-N-methyl-4-stilbazolium tosylate (DAST) single crystal hold the predominant place on potential organic nonlinear crystalline materials and electro-optic applications. In this present work, we have reported the synthesis and growth of ZnCl₂-doped DAST single crystals with different concentrations. The crystal was grown by the slow evaporation technique at room temperature. Structural and lattice constants of the grown crystals were determined by the powder X-ray diffraction (PXRD), and furthermore, confirm along with single-crystal X-ray diffraction (SXRD). FTIR studies affirm the presence of different vibrational modes of assignments and the presence of elements in the grown crystals was identified by EDAX study. The linear optical properties confirmed by UV–Vis absorption studies, and the calculated bandgap energies for pure 2.19 eV and dopants have 3.46, 3.41 and 3.36 eV for suitable materials for insulating and semiconductor behaviors. The second harmonic generation (SHG) output received from the pure and doped DAST crystal with applied input laser energy is 1.1 mJ/pulse using Kurtz–Perry powder technique. The obtained SHG efficiency for 0.01 mol ratio dopants have slightly less than the pure is 0.96, and 0.03, 0.05 mol, has 1.20 and 1.80 times greater than that of DAST. Hence, the results reveal that the doped crystal is very useful for optoelectronic and terahertz applications.