The Application Research Of PEDOT:PSS Transparent Electrode In Organic Optoelectronic Devices

In recent years, with the advantages of low-cost, large-scale preparation, wide range of material selection and flexible, organic optoelectronic devices have received considerable attention. In order to achieve flexible folding, find the ideal flexible transparent electrode is an urgent problem. The conductive polymer, poly(3,4-ethylenedioxythiophene): ploy(4-stytenesulfoate)(PEDOT:PSS) has good flexibility, high transmittance, easy processing, is a very potential ideal flexible transparent electrode, however there still exist problems such as poor stability, low conductivity of thin films, mismatching with wide band gap hole transport materials, lack of application at the cathode. This thesis mainly engaged in organic light-emitting devices(OLED) and organic solar cells(OPV) as the research object, system to optimized the preparation process, investigated the influence of substrate pretreatment and annealing conditions to film and photoelectric properties of PEDOT:PSS films; doped with high-boiling organic solvent to improve and repair photoelectric properties of PEDOT:PSS; investigated the practicability of adjusting film work function with function layer in electrode interface. Research conclusions are as follows:1. Optimization of PEDOT:PSS thin film preparation process. Firstly optimized oxygen plasma treatment conditions of ITO surface systematically, improved the surface properties of ITO so that the PEDOT:PSS solution can form a uniform film on the surface of ITO; Secondly, optimized the annealing parameters of PEDOT:PSS films. The result showed that the properties of PEDOT:PSS films was closely related to annealing conditions, with the appropriate annealing temperature and time, good connectivity between the particles will increase the conductivity thereby improving the device performance.2. Study on repair of invalid PEDOT:PSS solution. The properties of PEDOT:PSS solution decreased with the growth of exposure to the air time. In this thesis, after doped with ethylene glycol and glycerol in invalid PEDOT:PSS solution, the invalid PEDOT:PSS solution would recover performance, corresponding electrical properties of organic light-emitting devices or even better than not exposed to the air environment of PEDOT: PSS films.3. Study on adjusting of work function with function layer on the surface of PEDOT:PSS. After introducing the Mo O3 function layer on the surface of ITO/PEDOT:PSS, device performance did not improve but decay with the increased Mo O3 thickness; After introducing the Cs2CO3 function layer on the surface of ITO/PEDOT:PSS, this structure present obvious cathode characteristics, can be used as electronic collection of solar cell devices. Moreover, after adding Cs2CO3 function layer on PEDOT:PSS surface, organic solar cell present photovoltaic characteristics, the open circuit voltage increased from 0V to 0.44 V, the short circuit current density was 10.84 m A/cm2 and power conversion efficiency was 1.85%. Successfully implement the use of PEDOT:PSS as the cathode and the electron collector.