The present invention relates to light emitting materials including a novel Ir complex, where the Ir is provided with a primary ligand selected from phenyl pyridine ligands substituted with at least one Cl atom. Such light emitting materials have been found to have a significantly enhanced photoluminescence quantum yield over other Ir complexes with a phenyl pyridine ligand having no Cl atom, or even over those with a phenyl pyridine ligand having a halogen atom other than Cl, such as a Br or F atom, and as a result specifically improve the efficiency of a light emitting device. The present invention further relates to the use of such light emitting materials and an organic light emitting device including such light emitting materials.
The present invention relates to light emitting materials including a novel Ir complex, where the Ir is provided with a primary ligand selected from phenyl pyridine ligands substituted with at least one Cl atom. Such light emitting materials have been found to have a significantly enhanced photoluminescence quantum yield over other Ir complexes with a phenyl pyridine ligand having no Cl atom, or even over those with a phenyl pyridine ligand having a halogen atom other than Cl, such as a Br or F atom, and as a result specifically improve the efficiency of a light emitting device. The present invention further relates to the use of such light emitting materials and an organic light emitting device including such light emitting materials.
Room-temperature combinatorial screening of cyclometallated iridium(iii) complexes for a step towards molecular control of colour purity
A library of emission spectra of 90 bis-cyclometallated iridium complexes has been obtained using a simple combinatorial approach performed at room temperature. Trends in emission maxima are rationalized using Hammett parameters and invoking inter ligand energy transfer (ILET) processes. The screening approach allowed us to observe trends in the broadness of emission spectra opening the way for a rational approach to the engineering of the emission colour purity at a molecular level. Finally limitations to the screening strategy are discussed using a case study that involves two different monodentate ligands.