| Research in organic light-emitting diodes (OLED) has been rapidly spread worldwide in recent years. It has become particularly interesting in the fields of flat-panel displays and lighting. In order to overcome the shortcomings of low efficiency, short lifetime, many new kinds of OLED are constantly emerging. However, it's still far from enough to research the luminescent process of these devices. In this dissertation, we investigate the electronic transport of the blend film and the energy transfer characteristic between different materials, based on the application of blend-layer and quantum dots-organic light-emitting diodes.In order to explore on the characteristic of carrier transport in organics light-emitting materials, we built the setup of time-of-flight (TOF) to measure the charge carrier mobility. We have optimized the requirements at first using monolayer material, and provided a method of selecting the sampling resistor. Besides, we have analyzed the carrier injection and transport properties of monolayer OLED of poly[2-methoxy 5-(2-ethylhexyloxy)-p-phenylene vinylene] MEH-PPV by various electrochemistry methods.Firstly, we investigate the energy transfer process of the blend films of electron transport materials Alq3 and hole transport materials MEH-PPV or PVK. The F?rster radius and the energy transfer efficiency are calculated. Moreover, we investigate the effect of energy transfer on the performance of device by both the PL and EL spectroscopy. Secondly, TOF technique is used to investigate the transport property of blend film. The result exhibits that the blend materials with equivalent mobility of hole and electron can be obtained by adjusting the concentration of the component.In this thesis, we report studies of the energy and charge transfer of the CdSeS QDs (Quantum dots) and organic small molecule material Alq3. With excitation at 530 nm, the fluorescence lifetimes in the blend films show faster decay than pristine CdSeS QDs and decreases with the concentration of Alq3 increasing. However, with excitation at 400 nm, the fluorescence lifetime of CdSeS QDs in blend films are dependent on the concentration, increasing at first and then decreasing as the CdSeS QDs concentration. The maximum lifetime is located at about 53 wt% CdSeS QDs concentration. The reason is that F?rster energy transfer from the Alq3 to CdSeS QDs exists simultaneously with the charge transfer and both compete with each other. These results foreshow that the emission of CdSeS QDs in the blend films can be adjusted by controlling and balancing the energy and charge transfer processes between Alq3 and CdSeS QDs. However, there is only energy transfer process between Alq3 and CdTeS/ZnS QDs, due to the presence of ZnS shell.In order to explore on the dynamics characteristic of carrier transport in the blend films of Alq3 and QDs, we measure the carrier mobility and the dependence on electric filed and QDs concentration. These results show that the positional disorder in the blend films will be increased with the increase of QDs concentration. Moreover, the charge transfer mechanisms between Alq3 and QDs will lead to the change of the charge carrier mobility.
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