Composition for forming film having wrinkle structure and method of forming the film

A method of forming a film, comprising:

• providing a composition comprising a first photo-curable agent, a second photo-curable agent, and a photoinitiator dissolved in a mixed photo-curable agent including the first and second photo-curable agents to form a composition layer on a substrate, the first photo-curable agent having a first cut off wavelength of light transmittance, the second photo-curable agent having a second cut off wavelength of light transmittance that is shorter than the first cut off wavelength of light transmittance;
• controlling a blending ratio of concentrations of the first photo-curable agent and the second photo-curable agent to control a size of a wrinkle structure;
• and
• curing the composition layer to form a film having a randomly ordered wrinkle structure,
• wherein the photoinitiator has a cut off wavelength of light absorbance less than or equal to about 310 nm, the cut off wavelength of light absorbance being the smallest light wavelength at which a solution layer has a light absorbance of less than or equal to about 0.05, the solution layer having a thickness of about 10 mm and including about 1.0×10−4 mol % of the photoinitiator.