White light-emitting devices based on the combined emission from red CdSe/ZnS quantum dots, green phosphorescent, and blue fluorescent organic molecules

We report on a white hybrid light-emitting device realized by combining red emission from CdSe/ZnS quantum dots (QDs), green emission from a phosphorescent organic complex tris[2-4(4-toltyl)phenylpyridine]iridium $\left[\text{Ir}{\left(\text{mppy}\right)}_3\right]$ , and blue emission from a fluorescent organic emitter $2,2^{\prime },7,7^{\prime }$ -tetrakis(2,2-diphenylvinyl)spiro-$9,9^{\prime }$ -bifluorene. Energy transfer processes from the organic components to the QDs have been analyzed versus the $\text{Ir}{\left(\text{mppy}\right)}_3$ concentration in order to optimize the device performances. A maximum external quantum efficiency of 2.1%, corresponding to a power efficiency of 2.2 lm/W at $13\text{mA}/{\text{cm}}^2$ , and a color rendering index of 89.8 at $10200\text{cd}/{\text{m}}^2$ were achieved.