A Study On Exciplex-based Organic Light-Emitting Diodes

Organic light emitting diode?OLED?has made a great development in the flat display and the solid-state lighting to replace LCD since 1980s.In recent years,the third generation of electromechanical luminescent materials of thermally activated delayed fluorescence?TADF?materials have gradually become the focus of research on OLED materials.From T₁ to S₁,the TADF materials can achieve nearly 100%internal quantum efficiency?IQE?.As the intermolecular TADF material,exciplex can also achieve so high IQE.However,its formation mechanism is not clear,especially the blue exciplex.In this thesis,the mechanism of exciplex is studied and a new type of exciplex device is prepared.?1?Utilizing m-MTDATA and TmPyPB to form blue exciplex,the mechanism is explained through the theoretical calculation.Because of its high triplet energy?2.54 ev?,it is used as a host material to develop high efficiency PhOLED.In addition,WOLED has been successfully prepared using the exciplex as the host material.These findings have a great effect on the design of the exciplex and the preparation of high efficient OLED.?2?Based on m-MTDATA/TmPyPB exciplex,four devices are prepared by different mixture between D and A.The effect of the structure on device performance has been made reasonable analysis.The blend device is the best choice.In addition,four devices are prepared by four different doped region and its influence on device performance are explained scientifically.?3?Based on the formation mechanism of exciplex and the blend device structure,two new-type exciplex systems?m-MTDATA/AB123 and NPB/AB123?are prepared.Firstly,the property of TADF is verified,and then the devices based on the new-type exciplex host material are prepared.This has a revelatory effect on the preparation of OLED decices with both exciplex and other properties,such as the ultra-long lifetime.