The Experimental And Quantum Chemistry Studies On Blue Fluorescence Materials With Anthracene Core And Their OLED Devices

Organic light-emitting devices (OLEDs) have become a research hotspot and drawn greatscientific attentions for more than three decades. Compared with traditional display devices, theyhave many advantages, such as self emission, easy preparation, wide viewing angle, flexible, lowerproduction costs and so on. In OLEDs, the design of electroluminescent materials and theoptimization of device structure play very important roles for device performance, which affect theprocess of commercialization of OLEDs. As anthracene derivatives have many distinctive features,such as high fluorescent quantum yield, good thermal stability, and excellent carrier mobility, theyhave been the reaseach highlights among the electroluminescent materials. In this work, based onanthracene core, three blue fluorescent polycyclic aromatic hydrogencarbons (PAHs) were studiedby experimental and quantum chemistry simulation. The main research contents are as followings:In chapter l, the research background and recent research development of OLEDs werereviewed; the structure of this thesis was introduced.In chapter2, various kinds of organic electroluminescent materials used for OLEDs werereviewed, such as fluorescent light-emitting materials and phosphorescent materials with bluefluorescent light-emitting materials discussed in detail.In chapter3, focusing on OLEDs, the operation principle, device structure and performancecharacterization were summarized. In addition, our device fabrication chamber and the test systemwere introduced.In chapter4, based on three anthracene derivatives, we studied the photophysical andelectrochemical properties; and thermal history was analized. Then employing one of theanthracene derivatice as emitter, OLED devices were fabricated. It could be concluded thatsubstitution on the main fused aromatic rings influences the behaviors of photophysiccal andelectrochemical properties of the materials. Moreover, these anthracene derivatives were verythermally stable.In chapter5, the basic concept and the method of quantum chemistry calculations wereintroduced. Using the quantum chemistry calculations, we optimized molecular structure andcalculated the reorganization energy of the three molecules. The derived energy levels wereconsistent with the experimental values. In addition, based on the three materials, we fabricatedorganic light-emitting devices with the structure of ITO (30/)/NPB (700)/PAH (450)/ Alq3(250)/MgAg (2000). It can be found that in OLED device, the energy levels (bothHOMO and LUMO) of the host-emitters play an important role in carriers injection andrecombination and also exciton diffusion.The chapter6is a conclusion.