Research Of Organic/inorganic Composite Structure Device

At present, OLEDs(organic light emitting devices) formed by the multi-layer structure of organic thin films, with flat, active high brightness, high contrast, fast response, low driving voltage advantages, is considered a new technology what most likely alternative to liquid crystal displays in the future. With technology developping, OLEDs in optical areas of research has made remarkable achievements. Although OLEDs has been years of research, but there are a series of problems such as low electron injection efficiency, poor stability and short life of the device. This is because most of the properties of organic photovoltaic materials are electron transport in nature,or the nature of hole transport, electron and hole mobility difference between the larger, which makes the imbalance of electron and hole injection, resulting in the overall device hard to improve luminous efficiency. And most organic materials are hole transport category, electron transport is very limited type of material, this is the reason why light emitting can not meet the requirements of practical now. In order to effectively solve the light-emitting existence of these problems, at the same time get a better light-emitting devices, Organic materials and inorganic composite materials prepared, full use of organic materials and inorganic materials with their respective advantages so that in flat panel display technology has great application prospect. The main work of this thesis is preparing organic / inorganic composite electroluminescent devices . This paper reviews the electroluminescent technology background and status, and current research progress. Again light-emitting OLED with no mechanism for basic exposition, understanding of organic / inorganic composite structure the development process of the device. In the second chapter introduces the components of the preparation process, but also the performance of the device key test parameters. Finally, the current prevalence of light-emitting device emitting efficiency is low, work issues such as device performance is not stable enough, our experimental group usedⅡ-Ⅵgroup inorganic semiconductor material as the hole buffer layer devices, preparation of organic / inorganic composite devices, and analyze the optical properties of the device.First use ofⅡ-Ⅵinorganic semiconductor material ZnO as a hole buffer layer to preparation organic / inorganic composite structure device: the device ITO/ZnO/ NPB/Alq3/Al. PR655-Keithley2400 system using measurements, by the current-voltage characteristics, brightness-voltage characteristic curve of luminous efficiency-voltage characteristics and energy band theory, on the ZnO buffer layer films as the hole to improve the physical mechanism of the device performance was discussed. That the introduction of ZnO hole buffer layer can block too much the holes from the anode, so that electrons and holes in the compound becomes more balanced, in order to achieve the improvement of luminescent properties of the device.Secondly,use the same forⅡ-Ⅵgroup inorganic semiconductor material ZnS as a hole buffer layer, the same structure prepared organic / inorganic composite structure device: ITO/ZnS/NPB/Alq3/Al. In the case of other conditions consistenting with the film parameters, comparing ZnO as a hole buffer layer, think that ZnS as a hole buffer layer that not only did not increase but decreased the efficiency of light-emitting devices, mainly because that the ZnS film that is too thin caused quantum tunnel effect, result in holes injection more.