Pure and barium ion (Ba2+)-doped ammonium di hydrogen ortho phosphate (ADP) crystals were grown from aqueous solution using a slow evaporation process. The presence of Ba2+ ions in the lattice was confirmed by X-ray diffraction (XRD) pattern of the grown crystals, which revealed improved transparency for the compound. Green emission was observed in photoluminescence studies of the grown crystals. The results of Fourier-transform infrared (FTIR) spectroscopy, ultraviolet-visible (UV-visible) spectrum analysis, energy-dispersive X-ray analysis (EDAX) and dielectric studies on the grown crystals were reviewed in detail. A regular slow cooling evaporation method was used to grow the crystals of pure and Ba2+-doped ADP from aqueous solution.