Patent ID: 9640769
Date: 2017-05-02
CPC Classifications: C09K,H01L,H05B

Claim:
1. A composition for an organic electroluminescent device, comprising a phosphorescent material, a charge transport material, and a solvent, wherein each of the phosphorescent material and the charge transport material is independently an unpolymerized organic compound, wherein at least one of the phosphorescent material and the charge transport material comprises two or more different materials, wherein the first oxidation potential of the phosphorescent material E the first reduction potential of the phosphorescent material E the first oxidation potential of the charge transport material E the first reduction potential of the charge transport material E satisfy the following condition: wherein when the composition contains two or more different charge transport materials, the first oxidation potential of the charge transport material E wherein when the composition contains two or more different phosphorescent materials, the first oxidation potential of the phosphorescent material E wherein the first oxidation potential and the first reduction potential are determined by cyclic voltammetry, wherein a tested material is dissolved in an organic solvent containing 0.1 mol/L of a supporting electrolyte to yield a 0.1 to 2 mM solution, oxygen is removed from the solution by bubbling of dry nitrogen, degassing under reduced pressure, or application of ultrasound, the solution in an electrically neutral state is subjected to electrolytic oxidation or reduction using a working electrode and a counter electrode at a sweep rate of 100 mV/sec, the potential of a first peak detected in the electrolytic oxidation or reduction is compared with the oxidation/reduction potential of a reference material, thereby determining the oxidation or reduction potential of the tested material, and the oxidation or reduction potential thus determined is further converted into a value versus saturated calomel electrode (SCE) as the reference electrode, and the converted value is defined as the first oxidation or reduction potential.