A composite luminescent material synthesized by forming a precursor solution, forming a perovskite quantum dot/polymer composite by transferring the precursor solution onto a first substrate, and forming a composite luminescent material by coating the perovskite quantum dot/polymer composite with a polydimethylsiloxane (PDMS) solution. An exemplary precursor solution may be formed by obtaining a first solution by dissolving a polymer in a first organic solvent, obtaining a second solution by mixing an inorganic metal halide solution and an organic amine halide solution, and mixing the first solution and the second solution.