Hybrid electroluminescence devices with solution-processed mixed emitting layers of red quantum dots and blue small molecules

Hybrid electroluminescence (EL) devices with mixed emission layers (EMLs) were developed to achieve balanced peaks from red quantum dots (QDs) and blue phosphorescent small molecules. The EML was prepared by mixing QDs and small molecules in an organic solvent, and then adding polystyrene to disrupt the aggregation of the host material. These unique bichromatic devices exhibited two distinct EL peaks with similar intensities over 10 V, and the voltage dependent EL spectra were investigated systematically. These hybrid EL devices showed a maximum luminance of 1057.7 cd/m² and a current efficiency of 2.45 cd/A. These results indicate that the unique mixed EMLs have potential for use as white devices using fewer fabrication steps.