Flexible but Mechanically Robust Hazy Quantum Dot/Glass Fiber Reinforced Film for Efficiently Luminescent Surface Light Source

Abstract

Color conversion films with haze have aroused interest for use in surface light sources for display and lighting applications. Surface patterning or addition of light scattering particles to the color-conversion film induces haze and consequently, improves the photoluminescence (PL) extraction. Herein, a CdSe/CdZnS quantum dots (QDs)-embedded glass fiber reinforced siloxane hybrid (QD-GFRH) film with high haze value is demonstrated, originating from refractive index mismatch between glass fiber and methacrylate-phenyl functionalized siloxane matrix. The hazy QD-GFRH film shows a twofold improvement in PL extraction, as well as robust mechanical properties, such as low thermal expansion (13 × 10−6 K−1) and high deformation resistance (E = 11.8 GPa), compared to conventional polymers. Because QDs are chemically dispersed inside the film by covalent crosslinking with siloxane matrix, the QD-GFRH film exhibits long-term (30 days) thermal and chemical stability against heat and moisture conditions [85 °C/5% relative humidity (RH), and 85 °C/85% RH]. Furthermore, the yellow photoemissive QD-GFRH film, with a smooth surface and large scale (A4 size, 210 mm × 297 mm size), is applied as a color-conversion film on a blue light-emitting diode and it covers a large color gamut (107% relative to National Television System Committee).