There Are Organic Light-emitting Preparation And Properties Of The Device,

Organic light-emitting technology is a novel field in display industry as well as one of the hottest research topics all over the world. This dissertation focuses on the preparation and structure optimization of organic lighte-mitting diode (OLED) in order to obtain high performance and multicolor device.First, the devcice with the structure of ITO/NPB(15nm)/Alq3(x)/ Mg:Ag was prepared by thermal deposition in high vacuum. The influence of tris-(8-hydroxyquinoline) aluminum (Alq3) film thickness on the dvicec performance was examined. The result shows that the film thickness of Alq3 has remarkable effect on the performance of OLEDs. In the case of Alq3 film thickness of 40 nm, the highest performance device was obtained. It also indicates that the change of Alq3 film thickness doesn't affect the emitting spectrum of the double-layer device.Compared with green light-emitting device, blue OLED has many problems such as brightness, efficiency, stability, and color saturation, in this study we investgaited the blue OLEDs systemically: 1) Double heterosturcture OLED was charaterized. Due to the introducing of electron transport layer Alq3 and hole-blocking layer BAlq3, the energy matching was more reasonable and the carrier injecting was more effective in the double-layer device. The maximum efficiency and luminance of this device attained to 1.90 lm/W and 10,000 cd/m2, respectively. 2) Device with the structure of ITO/NPB/BAlq3/Alq3/Mg:Ag was prepared. It shows when the film thickness changes, the emission spectrum was shifted from green to blue. The reason to cause this phenomenon is due to the change of electric field in the blue OLED to induce the probality of the carrier shifted and the hole-electron recombination zone changed, which was a possible alternative to achieve color display. 3) Device with the structure of ITO/NPB/ADN:BAlq3/Alq3/Mg:Ag was fabricated. When the BAlq3 dopant concentration was about 25 mol%, a high performance devcie with luminous efficiency of 1.0 lm/W, the peak of emission spectrum at 440 nm, the CIE coordinate at (0.18, 0.15), and half lifetime of unencapsulated device about 950 hrs was achieved. 4) NPB, BAlq3 and TBP as dopants were doped into ADN matrix. It indicates not only were the...