Research On Key Manufacturing Technology Of Carbon Quantum Dots Based Organic Electroluminescence Devices

Organic electroluminescence devices?OLED?have made remarkable achievements and breakthrough after decades of development.Both in the field of research or in commercialization have made great progress.However,there are still some problems with OLED,such as the choice of light-emitting materials is less and expensive,the stability and life of the device is low,and the process is complicated,etc.In view of the above problems,this paper puts forward some new thoughts and ideas.A more cleaner,environmentally friendly and inexpensive carbon quantum dots material was used in OLED,which designed to increase the efficiency of the device,reduce the preparation cost and decrease environmental pollution.Carbon quantum dots based organic electroluminescent devices were fabricated.Carbon quantum dots nanomaterials were prepared by method of microwave,and the prepared carbon quantum dots were characterized by TEM.Carbon quantum dots were prepared in the organic structure of OLED by the method of vacuum coating technology and spin coating technology,and the effects of carbon quantum dots on the blue OLED with the structure of ITO/m-MTDATA/ NPB/CDs/BCP/Alq3/Al,red OLED with the structure of ITO/m-MTDATA/NPB/CDs/ Alq3:Rubrene:DCJTB/Alq3/Al and yellow OLED with the structure of ITO/m-MTDATA/ NPB/CDs/MADN:Rubrene/Alq3/Al were studied respectively.The experimental results show that the OLED with the function of the carbon quantum dots is superior to the traditional OLED devices in terms of the brightness and luminous efficiency.The carbon quantum dots as biological phosphor were prepared,and the conversion of light emitting devices with carbon quantum dots as phosphor was studied.Based on the inhibitory effect of starch on the luminescence quenching of carbon quantum dots,the carbon quantum dots phosphor with starch as matrix was prepared.A blue OLED with emission wavelength of 463 nm was prepared.Under the excitation of blue OLED,the phosphor showed stable green light emission.In addition,the influence of phosphor thickness on the device was studied by preparing phosphor with different coating thickness.Finally,when the phosphor thickness is 1mm,the prepared phosphor device exhibits green light emission with color coordinates of?0.35,0.46?.The experimental results show that the carbon quantum dots phosphor can effectively change the spectrum and chromaticity of the device,and achieve the modulation of the light.The effect of nickel oxide nanostructured buffer layer on the performance of blue OLED was studied.Through the measurement and characterization of the NiO particle morphology,it has been proved that the NiO particles prepared by the electrochemical deposition method have good nanostructure.According to the different deposition time of Ni film,four groups of comparative experiments were prepared.The experimental results show that the nanostructured NiO buffer layer can effectively improve the hole injection efficiency,thereby increasing the hole-electron pair generation and recombination efficiency.Finally,when the deposition time of Ni is 30 s,the device has the best luminescence performance.OLED based on PET substrate and glass substrate were prepared,and the effect of flexible substrate materials on the performance of the device was studied.The experimental results show that the multilayer structure based on PET substrate exhibits good light emission characteristics.However,compared to rigid substrate devices,flexible devices still have some defects in the luminance,luminous efficiency and current density.In view of the current problems in the flexible devices,the paper puts forward the improvement measures of adding the SiO₂ improvement layer between flexible substrate material and anode material.At the end of this paper,the encapsulation methods for flexible OLED were introduced.One method is to prepare a thin film barrier on the device;another method is to add a flexible cover between the substrate and the functional layer.Both encapsulation techniques provide a reference for improving the performance of flexible displays.