In this study, the crystalline 1,5-diaminonaphthalene lead iodide [C10H6(NH3)2]PbI4 (DANPI) was investigated for synthesis conditions in two methods: (i) crystallization in the above-mentioned solution,and (ii) crystallization in a solution with temperature gradients. Optical microscopy and powder X-ray diffraction (XRD) was used to evaluate crystal structure, and the luminescence of the formed crystalswas determined by photoluminescence spectroscopy (PL). The results showed that DANPI crystals were formed in the solution with temperature gradients but no crystals were formed using the method of decreasing temperature. Observed under an optical microscope, the obtained crystals are orange in color, about 200 µm in size, almost square in shape, with sharp crystal edges, and thin plates. The XRD data showed that obtained DANPI crystal has a monoclinic (monoclinic) lattice type, space group P21c (14) with lattice parameters a, b, c are 11.2252 Å , 8,9337 Å, 8,7750 Å, respectively, and α = γ = 90o, β = 90,601o. The PL spectrum showed that the material was capable of emitting in the 520 nm to 550 nm region, corresponding to the green color.