A series of organic-inorganic hybrid tin halides formulated as Sn(phen)XmYn (phen = 1,10-phenanthroline, X/Y = Cl, Br, I, m + n = 4) were designed and prepared to study main group metal halides as photosensitive dyes. The colors of compounds are tunable with the change of mole ratio of the halides due to the ligand to ligand charge-transfer (LLCT). Intense visible-range absorption can be obtained by increasing the mole ratio of iodine and intense ultraviolet fluorescence emission can be obtained by increasing the mole ratio of chlorine. DFT calculations suggest that the LLCT occurs from electron-rich halide ion to π* orbit of phen. The iodide materials have narrow energy gap and suitable energy level of the excited state for exciton transfer to TiO2 semiconductor. Photocurrent responses experiments using the compounds treated TiO2 electrodes showed that upon irradiation stable photocurrent generated and Sn(phen)I4 has the best photosensitive behavior.