Preparation of quantum dot luminescent materials through the ink approach

Highlights: • Quantum dot luminescent films were prepared by "ink" approach using urethane acrylate. • This "quantum dot ink" has better polymer–particle interfacial adhesion and can overcome quantum dot aggregation. • This approach is promising to prepare quantum dot related luminescent device components. Highly transparent and luminescent UV curable polyurethane acrylate/quantum dot (QD) nanocomposite material was prepared using "QD inks" approach by UV curing. First, water soluble CdTe QDs (λ_em = 510 nm, 540 nm and 620 nm) were synthesized. Urethane acrylate prepolymer was used as the media for the "QD ink" and 2-hydroxy-2-methylpropiophenone (HMPF, also called 1173) was used as the photoinitiator. FT-IR spectra showed that there were strong vibrations at 1725 cm⁻¹ which was contributed from the –CO groups after the polymerization, while the end –CCH₂ group vibration at 964 cm⁻¹ and 993 cm⁻¹ disappeared. Thermogravimetric analysis of the resultants showed the 5% weight loss up to 150 °C which was the free water content; and 9.18% loss of the weight was the dehydrate of the resins in 150 °C–301.75 °C; weight loss of 93% from 300 °C to 450 °C was the decomposition. Mechanical tests showed that the elongation at break was 12.96%, and that the tensile strength was 5.39 MPa. This "QD ink" approach is attractive in the preparation of luminescent materials and thus is prospective in the development of QD devices.