Study On The Magnetic Field Effect Of Organic Light Emitting Diodes Based On AlQ Luminescence

Organic light emitting diodes(OLED)have always been a research hotspot in the field of organic optoelectronics because of their significant advantages in flat panel exhibit technology applications and solid-state lighting.At present,the application prospect of OLED is still limited by its complicated internal micro process and production technology.Since Kalinowski found organic magneto-conductivity effect and organic magneto-electroluminescence effect in organic lightemitting diodes based on small molecule 8-hydroxyquinoline aluminum(AlQ),researchers began to use organic magnetic field effects(MFEs)to study the internalmechanism of OLED,and realizing effective regulation of the organic magnetic field effect is one of the modus to resolve the narrow application prospects of OLED.In addition,there are still few researches on the regulation mechanism of the organic magnetic field effect.Although some research groups have conducted similar discussions,compared with the complexity of the internal process of OLED,the effective control method of the organic magnetic field effect is still insufficient.Therefore,the study of more extensive methods of regulating the organic magnetic field effect has certain value and significance in promoting the development and application of OLED.The organic semiconductor light-emitting material AlQ(Alq3)has been widely used in theoretical research and industrial productionbecause of its good thermal stability.Therefore,in this paper,organic electroluminescent devices with different structures have been prepared based on AlQ,and we study its photoelectric properties and magnetic field effects,the study provides a new method and way to realize the effective regulation of the organic magnetic field effect.The main point of this paper contains the following parts:The first chapter presents the research history and status quo,device structure and light-emitting theory of organic light emitting diodes.Then the organic magnetic field effect is introduced from the aspects of research progress,theoretical basis and physical mechanism.Finally,the research significance and main content of this thesis are introduced.Chapter two first introduces several methods and manufacturing processes of organic light emitting diodes.Then the method to measure the photoelectric characteristics and magnetic field effects of organic light emitting diodes is introduced.In the third chapter,AlQ:LiQ is used as the electron transport layer,and the optical-electromagnetic integrated measurement technology is used to study the result of the electron-transport layer on the magnetic-field effect of the organic light-emitting diode.At different voltages and temperatures,measured the changes in the current intensity and electroluminescence intensity of the device(ITO/MoO3/NPB/AlQ/AlQ:LiQ/CsCl/Al)with the effect of an external magnetic field,and confirms the truth of magnetic-conductance effect(MC)and magneto-luminescence effect(MEL)of the device under different voltages and different doping thicknesses,the mechanism of the magnetic-field effect of the device at low temperature is also discussed.The experimental results prove that by converting the doping thickness of the electron transport layer,the electron injection can be effectively controlled,so that the triplet exciton concentration of the light-emitting layer can be adjusted,and finally the organic magnetic effect can be adjusted.The fourth chapter uses AlQ as the device connection layer,and the structure is successfully prepared as ITO/MoO3(5nm)/NPB(30nm)/AlQ(40nm)/CsCl(1nm)/AlQ(0,5,10,15nm)/MoO3(10nm)/NPB(30nm)/AlQ(40nm)/CsCl(0.5nm)/Al(120n m)stacked organic electroluminescent devices,and the influence of the thickness of theconnection layer,the bias voltage of the device and the temperature on the magnetic field effect of the stacked device is systematically studied.The test consequences testify that the thickness of the connection layer of the laminated devicehas a great influence on various interactions within the device,and the level of saturation of the MEL can be controlled by changing the thickness of the connection layer.The work in this chapter gives us a deeper understanding of the working mechanism and magnetic effect mechanism of laminated organic light emittingdiodes,and further enriches the research on the magnetic effect mechanism of laminated organic light emitting diodes.Chapter five is to use CoPc as the anode buffer layer to prepare the structure ITO/MoO3(5nm)/CoPc(0,2,4,6nm)/NPB(60nm)/AlQ(80nm)/CsCl(0.6nm)/Al(120nm),the MC and MEL curves of the device were measured experimentally.The effects of applied-voltage,buffer-layer thickness and temperature on the MC and MEL curve are discussed,and the process of magnetic effect mechanisms such as HFI,STT,TTA,and TQA are discussed.The experimental results prove that changing the thickness of the buffer layer has a great effect on effectively regulating the magnetic field effect,which further enriches the research content of the organic magnetic field effect.