Device Modeling of Quantum Dot–Organic Light Emitting Diodes for High Green Color Purity

In this study, the optimal structure for obtaining high green color purity was investigated by modeling quantum dot (QD)–organic light-emitting diodes (OLED). It was found that even if the green quantum dot (G-QD) density in the G-QD layer was 30%, the full width at half maximum (FWHM) in the green wavelength band could be minimized to achieve a sharp emission spectrum, but it was difficult to completely block the blue light leakage with the G-QD layer alone. This blue light leakage problem was solved by stacking a green color filter (G-CF) layer on top of the G-QD layer. When G-CF thickness 5 μm was stacked, blue light leakage was blocked completely, and the FWHM of the emission spectrum in the green wavelength band was minimized, resulting in high green color purity. It is expected that the overall color gamut of QD-OLED can be improved by optimizing the device that shows such excellent green color purity.