Optically enhanced organometallic ZnSO₄-doped p-dimethylamino-N-methyl-4-stilbazolium tosylate (DAST) single crystal is grown by cost-effective solution growth slow evaporation technique. Further, we investigated the dopant effects on DAST with different device properties, the structural parameters of grown single crystals were analyzed through single X-ray diffraction, powder X-ray diffraction, energy dispersive X-ray analysis (EDAX). The lower cut-off wavelength of absorbance of ZnSO₄-dopant crystals are 379, 380, 382 nm and of DAST is 388 nm which was analyzed by UV–Vis absorption spectra that reveals the improvement of optical effects. The photoluminescent spectra revealed that the pure and ZnS-doped DAST crystals exhibiting green emission characteristics which help to fabricate the green LED. The SHG studies revealed that the enhancement of second-order nonlinear efficiency of ZnSO₄-DAST-dopant crystals (ZnS 1, ZnS 3) is 1.1, 1.4 times higher than DAST and SHG efficiency of ZnS 5-doped DAST crystal decreased due to deformation of crystal structure. The thermogravimetric analysis exhibits good thermal stability such that 258.74 °C for pure and 259.41, 259.77, 258.94 °C for ZnSO₄-dopant crystals which ensures that the high thermal stability than DAST crystal. The exploration of various properties of the results of grown ZnS-doped DAST crystals are utilized exclusively in the fields of optoelectronic and nonlinear optical (NLO) device applications.