Study On Organic Light-Emitting Devices Improved By PANI Conductive Polymer

With the rapid development of economics, People have been aiming to research FPD (flat panel display) characteristic of the properties of super-slim,high definition. In comparison with the traditional displays such as CRT, LCD, OLED (organic light-emitting display) has been looked as "the third generation"flat panel displays and aroused great interests among researchers and industries due to its outstanding advantages including active light-emitting, wide viewing angle, high definition, low power consumption, prompt response and good aseismatic performance. However, the existing OLED is expected to be further improved because there still have been some deficiencies such as poor stability, short life-span , low emissive efficiency and so on in it. Therefore, in this paper we'll apply conductive polymer to modify ITO surface in expectation of improving the contact properties between ITO electrode and MEH-PPV light-emitting materials, and consequently polymer OLED which is stable in light-emitting performance are obtained. The following is included: 1) To analysis the character of OLED briefly and put emphasis on discussing mechanism of light-emitting, principles of working, structure, light-emitting materials and so on. And then to survey the present status and prospects in application about polymer OLED. 2) To design and fabricate the single layer and double layers polymer OLED which possess the structure of ITO/MEH-PPV/Al and ITO/Pan/MEH-PPV/Al respectively; To explore the influence of MEH-PPV concentration on the thickness of organic films by measuring the thickness of films between MEH-PPV luminescence layers. 3) To create PAn films which are different in character by means of the electrochemical polymerization or transforming PAn solution obtained by chemosynthesis into films through rotate coating method. Then to character the properties of structure,conductivity, surface appearance and optics and so on. The primary results show that the rotate coating method is superior to the electrochemical polymerization. 4) To investigate the threshold voltage, light-emitting intensity, life-span time of polymer OLED. The results indicate performances of the double layers devices are fundamentally superior to that of the single layer devices. This may have something to do with the factors that deficiencies are reduced and complex efficiency of carrier is improved after the ITO electrode is modified by PAn. 5) To Analysis the surface appearance of polymer OLED before and after it is out of effect through SEM, It was found that Joule heat originating from the working process of the devices make water and oxygen in air constantly saturate into the inside of the devices, oxidation and corrosion occur on the surface of Al electrode , organic light-emitting layer ages gradually, finally these lead to the devices's being out of effect thoroughly.