Study On New Pyrene Derivatives And Its Applications As Solid-State Lighting

At present,the OLED device prepared by the solution method not only has the problem of high driving voltage,but also faces the problem of serious roll-off under high brightness.At the same time,it also faces the problem of lack of high-performance materials.As a third-generation luminescent material,the delayed luminescent material has the advantages of high efficiency,low cost,and environmental friendliness,and thus has attracted widespread attention.In this paper,some problems in the wet preparation of OLED devices using delayed fluorescent materials are studied.(1)In order to solve the problem that the starting voltage of OLED devices is generally high due to the solution method,in this study,the “stepped” energy level structure is realized using the blended main body,and four kinds of main bodies are studied,namely MCP,MCP: TAPC,and MCP: TAPC:OXD-7,TCTA:TAPC:OXD-7,guest material is red delayed fluorescent material TXO-TPA.Through the exploration and optimization of the main structure,a low-light-on-voltage OLED device was prepared,and the on-off voltage was reduced to 2.7 V.(2)For the OLED device prepared by the solution method,the problem of high roll-off efficiency under high brightness is serious.The polymer matrix PVK is used and a green TADF material 4Cz IPN is doped as a guest.Through the exploration of the solvent system to control the interface and film morphology,an OLED device with the best performance was prepared with a brightness of 56120 cd/m2,a current efficiency of 23.4 cd/A,and an efficiency roll-off of less than 18%(1000-10000 cd/m2),achieving high brightness,high efficiency,low roll-off OLED devices.(3)Finally,in this study,four quinone derivatives were used as sensitizers,which were introduced into the luminescent layer to prepare red TADF OLED devices.Sensitized TADF devices were prepared by the sensitization of reagents and the combination of the light-emitting layer structure.It was finally found that when a sensitizer was added using a PVK:OXD-7:4CZIPN host,doping with a sensitizer of 3 wt% significantly improved the performance of the device,the brightness increased by 17%,and the efficiency increased by 49%.When using PVK:OXD-7:30 wt% TXO-TPA host,doping sensitizers also improved the device performance,with 5% sensitization being the best.