The Structure And Performance Study Of Field Emission Cathode OLED Devices

Organic light emitting diodes as a new generation of flat panel displaytechnology, has a series of advantages, such as ultrathin, super light，widelyperspective, active emitting, high luminous efficiency, short response time and lowdriving voltage, wide color gamut and so on. In recent years OLED has become ahotspot in research of flat-panel display. Since2003, this kind of display technologyis applied on the MP3players and other screen. But OLED devices have problems inlife and luminous efficiency, thus limits its popularization and application.At present, the domestic and foreign research related to OLED devices aremostly looking for a better device structure and invention of new organic material. Interms of device structure, in order to combine OLED display and mature silicontechnology, people put forward the silicon-based top launch OLED devices (top-emitting organic light emitting diode, TOLED). In this kind of device structure, lightcomes from the transparent electrode, and circuit can be designed on the silicon. Sothis kind of TOLED solves the light-emitting area and the driving circuit competingproblem, improving the luminous efficiency of the device. However, the preparationof transparent eledtrode of TOLED devices has also become a difficultproblem. From this perspective, this thesis mainly does the following three aspects:1．The study of the organic layer thickness matching. We prepared the traditionallaunch OLED devices on the ITO glass substrate, and studied the thickness matchingaffect of the electron transport layer Alq3and the hole transport layer NPB on theperformance of OLED devices. At last we discussed the hole buffer layer (CuPc)effecting on the stability and the life of the device.2．The energy filter magnetron sputtering technology preparation of ITO thinfilm technology research. We prepared ITO thin film by the energy filteringmagnetron sputtering (EFDMS) technology, and discussed the photoelectricproperties of ITO films with different filtering electrode wangshan mesh and the substrate temperature. Experimental results show that when wangshan meshs were60mesh,70mesh,80mesh,100mesh,110mesh,120mesh,130mesh,150mesh,170mesh,200mesh,220mesh and300mesh, the resistance of the ITO thin film firstincreased then decreased with the change of mesh. When WangShan mesh increasedto200mesh, film resistivity of the lowest is4.7×10-4Ω.cm, and the highest lightincreased to93%. In low temperature range, the influence of temperature on the filmin the visible light transmittance is not very big. As the temperature increases, thetransmittance of ITO thin films increased slightly and the resistivity is lowering.When the temperature is90℃, the resistivity of thin films is lowest and thetransmission of light is best.3. The research of TOLED device. The traditional launch OLED devices wasprepared on the glass substrate. The device structure was Al/Alq3/NPB/ITO. The ITOanode was prepared respectively with the method of DMS and EFDMS. Wecompared the effect of luminescence brightness and current density for TOLEDdevices with different preparation methods of ITO anode.We prepared Si/C/Alq3/NPB/CuPc/ITO device, which Si was treated withdifferent methods. With king kong gypsum grinding, HF cleaning, Ti platingprocessing the silicon substrate, we prepared the nanometer amorphous carbon filmon the substrate. Compareing carbon membrane surface morphology and structuralproperties with different treatment on silicon substrate,We prepared TOLED devicewith different carbon membrane as the cathode and metal Al film as anode. Theexperimental results show that the silicon TOLED with Ti plating on deviceperformed was best, HF cleaning silicon was second and grinding of silicon deviceperformed was the worst. Finally，with Ti plating amorphous carbon membrane as thecathode, with EFDMS technology preparation of ITO as the anode, we prepared theSi/C/Alq3/NPB/CuPc/ITO device and research its current density and brightnesscharacteristics.