Pure room temperature phosphorescence emission of an organic host-guest doped system with a quantum efficiency of 64%

A new doped system with pure phosphorescent emission is constructed using four 1-(4-(diphenylamino)phenyl)-2-phenylethan-1-one derivatives containing halogen atoms as the guests and benzophenone as the host. That is, the doped system has only phosphorescence emission while almost no fluorescence emission and the phosphorescence quantum efficiency reaches up to 64%. Moreover, the ISC efficiency of excitons can be adjusted by changing the excitation wavelength, so the doped materials can selectively emit green phosphorescence or cyan fluorescence.