Design And Photoelectric Properties Of Organic Light Emitting Diode Devices

Organic Light Emitting Diode(OLED)is very promising in the field of flat panel display and solid-state lighting due to its unique advantages such as self-luminescence,surface light source,fast response speed,wide viewing angle,and thin thickness.In this paper,the fabrication and performance optimization of red phosphorescent OLED devices based on Undoped Emitting Layer(UEML)were carried out;the electron injection layer of red phosphorescent OLED devices based on Alq3 simple device structure and undoped structure was studied;And proposed the device structure of organic-inorganic stack(OLED on ILED),carried out the layout design of blue ILED(Inorganic Light Emitting Diodes)based on monolithic integration process improvement,and prepared and tested blue ILED.1.Traditional doped phosphorescent OLEDs are unstable due to the uncertainty of co-evaporation.In this paper,a novel structure-host-guest stacking undoped red phosphorescent OLED is proposed,and its host-guest stacking layer number,singlehost thickness and single-guest thickness are optimized.It is concluded that the best repeated stacking layer number is 5 layers.When the thickness of the single host is 3nm,the device has better performance than other single host thicknesses,and when the thickness of the guest is 0.2 nm,it also has better performance.And the current efficiency of undoped device is not lower than that of the traditional doped device,and shows better repeatability of device fabrication.2.Effective Electron Injection Layer(EIL)is one of the important factors to achieve high performance of OLED devices.In this paper,we propose the use of sodium fluoride(NaF),cesium fluoride(CsF)to replace the traditional lithium fluoride(LiF),and demonstrate the improved OLED while changing the thickness of sodium fluoride,cesium fluoride(CsF)as EIL device performance.Firstly,the performance comparison of LiF,NaF,CsF and CsCl as the electron injection layer was carried out on the OLED device based on the Alq3 light-emitting layer.Then,some mechanisms of the performance difference of LiF,CsF,NaF as electron injection layers were studied,and the conclusions related to their atomic diameters and ionization energies were drawn.3.Based on the above research basis,the device performance of undoped red phosphorescent OLEDs based on CsF as the electron injection layer and TPBI as the electron transport layer was studied,which is similar to the above based on Liq and Bphen(4,7-diphenylene)-1,10-phenanthroline)undoped red phosphorescent OLEDs were compared for performance,and it was found that using CsF as the electron injector,its maximum current efficiency at a thickness of 2 nm was higher than that of Liq and Bphen undoped OLEDs.The red phosphorescent device has a 2x performance Impro vement.The thickness variation of the cesium fluoride EIL results in a very balanced electron injection,which is also applicable to the fabrication of other OLED devices.Using an optimized EIL is one of the beneficial ways to improve the performance of OLED applications.4.The display panel usually adopts the horizontal arrangement of sub-pixels to achieve full color.Such low geometric fill factors and complex alignment processes inherently limit display panel resolution improvements.In this paper,an organicinorganic composite light-emitting structure of OLED on ILED is proposed,and the display device is fabricated by vertically stacking sub-pixels,which will greatly incr ease the fill factor,thereby realizing ultra-high-resolution display.And the blue ILED layout design work was carried out,the blue ILED was prepared by 7-step lithography,and the related properties of the blue ILED were tested,and some related process research was also carried out.