Synthesis And Oled-device Performance Of Spiro [Fluorene-9,9'-xanthene]-based Electroluminescent Materials

Nearly 30 years of research,organic light-emitting diodes?OLEDs?have been used in the field of flatpanel display and solid-state lighting.Spiro[fluorene-9,9?-xanthene]?SFX?has three-dimensional orthogonal configuration,wide bandgap and bipolar characteristics.It can be synthesized by a facile“one-pot”route,thus is very cost-effective,and it has multiple positions on the aromatic units for functionalization.Therefore,SFX-based phosphorescent host and guest can obtain high performance and low cost OLED light emitting layer material.In this paper,firstly,2?-SFXpy and 2-SFXpy compounds was synthesized by a simple"one-pot"Friedel-Crafts cyclization and Suzuki-Miyaura coupling reaction.The two compounds were compared by their nuclear magnetic resonance.The photophysical and electrochemical properties of the two compounds were studied by UV-Vis absorption spectra,fluorescence spectra and single crystal X-ray diffraction.All of the research results indicate that the 2?-SFXpy is a promising phosphorescent blue OLED host material.Secondly,Ir?SFXbtz?₃ and Ir?SFXpy?₃ complexes were SFX-based orange and yellow phosphorescent emitter material.The properties of the OLED devices were systematically investigated by vacuum evaporation.Orange/red devices results show that the performance of the device is less affected by the thickness of the light-emitting layer.The white phosphorescent OLEDs were prepared by vacuum evaporation method using Ir?SFXbtz?₃ and Ir?SFXpy?₃ as phosphorescent emitter.The results show that Ir?SFXbtz?₃can be used as red-orange material to fabricate white light device.and the barrier layer Ir?ppz?₃ was introduced into the light emitting layer to improve the device performance.When the 3nm electron blocking layer was introduced into the light emitting layer,the current efficiency,power efficiency and color coordinate of the devices based on Ir?SFXpy?₃ were 16.70cd/A,15.06m/W and?0.29,0.41?.The device without the introduction of electron blocking layer light shines off the white area.The efficiency of white light device made of complex Ir?SFXbtz?₃ is higher than that of white light device made of complex Ir?SFXpy?₃?...