Thin films were grown by vacuum co-evaporation of CsI and PbI₂ compounds from two independent crucibles. X-ray diffraction spectroscopy revealed formation of CsPbI₃ and Cs₄ PbI₆ nanoaggregates in the thin film samples and gave an estimate of their volume percentage as well. It provided also the grain size estimates, which were compared with direct observation of a thin film surface by atomic force microscopy. The absorption, luminescence and decay kinetics characteristics of thin films grown were measured. The optical characteristics of the mentioned ternary nanoaggregates were determined and compared with those of CsPbX₃ and Cs₄ PbX₆ (X = Cl, Br) bulk structures.