High‐Transmittance and High‐Haze Composite Particle‐Free Optical Diffusers Enabled by Polymerization‐Induced Phase Separation

Abstract

Optical diffusers with combined high transmittance and high haze are desired for the light management of various optoelectronic devices. However, the fabrication of such optical diffusers is still a grand challenge, limiting the wide application of optical diffusers. Herein, a technique by combining polymerization‐induced phase separation (PIPS) and postpolymer encapsulation to make composite particle‐free optical diffusers is proposed, achieving combined high transmittance and high haze. By altering the composition of two porogens, the morphology of the porous structure can be well tailored, which generates different scattering modes. Furthermore, the transmittance and haze spectra can be tuned by varying the diffuser thickness. At an optimized form, a composite optical diffuser is capable of achieving superhigh haze (88%), while maintaining a high degree of transparency (88%). Finally, the optical diffusers are applied to phosphor‐converted light‐emitting diodes for color uniformity enhancement and quantum dot films for photoluminescence intensity improvement. The present technique provides a facile, low‐cost, and easily scalable route for making optical diffusers with high transmittance and haze, which may facilitate their real‐world application.