The Preparation And Study On Conductive Polyaniline/ITO Electrode For Organic Light Emitting Diode

In this paper,it introduces the light-emitting principle of OLED and performance evaluation index,and briefly reviews the ITO transparent electrode and conductive polyaniline modified ITO transparent electrode.The basic structure characteristics of the conductive polyaniline,synthesis technology and application are summarized.The application and significance of PANI/ITO composite electrode in OLED device is briefly reviewed.The sol-gel method was used to prepare ITO sol,then the transparent ITO conductive film on the transparent glass is prepared by spin coating technique;Electrochemical polymerization technology was used to prepare experiment composite electrodes.Organic luminescent materials were deposited by spin coating and steaming plating on experiment composite electrode surface for OLED devices.Raman,UV-Vis NIR spectra were used to study the composition and light transmittance of ITO spin coated films.The effects of sintering heat treatment temperature on the crystallinity of ITO spin coating film were investigated by XRD.The morphography of the surface of the specimen was observed by AFM.The surface resistance was measured with a four point probe,Raman,SEM and four point probe were used to study the process of the polymerization of aniline monomer on the surface of the ITO.The luminescence properties of the OLED device was examined by luminance meter,the main conclusions are as follows:?1?Indium tin oxides films prepared by sol-gel spin coating were mixed by In₂O₃ liked cubic bixbyite structure and SnO_x.The films were smooth and the light-transmittance were above 70%.The square resistance of films by spin coated for several times was about hundreds of ohms.The block resistance of thin film with higher sintering temperature is smaller under the same coating layer,and The block resistance increases with the thickness of the coating layer under the same sintering temperature.?2?when the heat treatment temperature was 300 ?,the XRD diffraction peaks of sample are the same to the indium tin oxide diffraction peaks.The grain size of sample increased and the crystal structure is more complete when the heat treatment temperature was 500 ??3?The difference of potential of each redox peak pair increases with the cycle number and scan rate increases with the cycle number and scan rate,and redox reversibility of the obtained PANI during aniline polymerization on ITO surface by cyclic voltammetry.In the potentiostatic method,aniline monomer contention greatly impact on the polymerization induction period.The polymerization of aniline was hard when the potentiostatic was lower 0.8V,in the same time,the PANI was capable to peroxidating and decomposing when the potentiostatic was higher 1.0V.?4?The ITO/PANI/Alq₃/Al organic electro-luminescent device was prepared in this paper.It was found that the PANI could effectively improve the performance of the device,and got the best performance when the concentration of PANI was 4 mg.m L-1?12nm?.It concluded that the introduction of PANI could effectively cut down the barrier of hole injection,at the same time,the electron was obstructed in the light emitting layer.The carrier recombination rate of electron-hole was improved.