Hybrid color-conversion layers for white emission from fluorescent blue organic light-emitting diodes

Abstract Hybrid color-conversion layers (CCLs) were developed to convert a blue emission from fluorescent organic light-emitting diodes (OLEDs) to obtain a white emission with a high color rendering index (CRI). The hybrid CCLs were composed of an inorganic phosphor, organic dye, and silicon dioxide (SiO 2 ) scattering nanoparticles. The inorganic phosphors convert a part of blue emission from OLEDs to a green-yellow emission effectively. A part of the green-yellow emission was consecutively converted to a red emission with the organic dye. Using the hybrid CCLs, we obtained a balanced white emission with the highest CRI of 93 and the color temperature of 3500 K. The high CRI white OLED showed the power efficiency of 11 lm/W which was enhanced by 1.9 times from that of the blue fluorescent OLED. We showed that the utilization of the SiO 2 nanoparticles did not only enhance the power efficiency but also significantly reduce the white color variation to the viewing angle.