Structural and optical properties of vacancy-ordered double halide perovskites, Cs2TiI6 films

•The possibility of synthesizing the titanium-based vacancy-ordered double halide Perovskites, Cs2TiI6 films via simple inverse temperature crystallization method.•Alternatives materials structural designed in overcoming the instability and toxicity issues of Pb-based perovskites.•The structural and optical properties including crystal structures, microstrain, dislocation density, absorption and band gap of synthesized Cs2TiI6 films was highlighted in this manuscript.•Provide insights into developing non-toxic and high-efficiency perovskite materials for optoelectronic devices.