Effects Of Doping And Annealing On The Electroluminescent Performance Of Ir（piq）₃

Organic light emitting devices (OLEDs) have attracted much attention during past decades for their application on flat panel displays and solid-state lighting. With the incorporation of phosphorescent heavy metal complexes, both singlet and triplet exactions could be harvested for light emission, therefore100%internal quantum efficiency, in principal, could be achieved in the phosphorescent OLEDs. Very high efficiencies have been achieved from small molecular based OLED via multilayer structures. The efficiency of polymer phosphorescent light emitting devices (PhPLEDs) are much less than that of small molecular devices, PhPLED is attractive due to its low cost and potential roll-to-roll manufacturing on large area based on varieties of printing techniques, this thesis of two aspects:First, based on the tested the electroluminescent characteristics of electro phosphorescent devices with Ir(piq)3phosphorescent materials doped PVK,mcp and TAZ.We analyze the energy transfer situation in the different host doped system Second, the influence of the Carrier transmission on the performance of the devices is also investigated. At last we investigate the influence of film surface morphology and Phase change of host and gust materials on the performance of the devices. This thesis consists of five chapters. In the first chapter, the development and the mechanism of organic light-emitting devices are introduced. The second chapter is aimed at the preparation and test method of Phosphorescent electroluminescent devices. The following two chapters study the above mentioned aspects by experiments and theory. The fifth chapter is the conclusion.(1) In this thesis, we use three different materials as the host and Ir(piq)3as phosphorescence guest, and study the electroluminescent characteristics of these three kinds of host in Ir(piq)3and the influence of carrier transmission in different doping density. When the concentration of Ir (piq)3doped with PVK, TAZ and MCP were20%,18%,18%, the device have a best performance. We analyze the energy transfer situation with the PL of the thin film of Ir (piq)3doped in PVK, TAZ and MCP with1%and3%in this different doped system. We conclude that the energy transfer of Ir (piq)3doping MCP system is better than the Ir(piq)3dopingPVKandTAZsystem.(2) Based on (1),We use Ir(piq)3material as phosphorescence gust, mep as the host material, and fabricate a series of device with doped different material of Transmission function. We investigate the influence of Carrier transmission in different doped density of PCBM and Alq3doped in emitting layer. It makes excitons easier to dissociation of the PCBM doped with emitting layer. When the emitting layer of doped with Alq3, carrier transmission characteristics are improved, It make electronic and hole better in Luminous center, it reduce the quenching of interface in different organic layer and Improve device performance. Furthermore, by different annealing of emitting layer, we study the influence of film surface morphology and Phase change of host and gust materials on the performance of the devices. We conclude that when the film emitting layer annealing temperature and time of annealing for90℃and15min, the luminescent properties of device are the best.