| The reason why organic light emitting device (OLED) displays are so attractive is that it has many superior advantages compared with liquid crystal displays, such as wide viewing angle, high color contrast, ultra thin, portable and flexible, etc. However, even though OLEDs have been developed for nearly thirty years and the performances have been improved dramatically, there are still many rigorous problems for optoelectronic materials as well as device structures, including complicated fabrication procedures, poor fluorescent blue emitters, unstable operational lifetime and most critical, poor electron transport materials. Therefore, our objectives are to achieve a robust blue emitters as well as high mobility and stable electron transport materials/composition. We also aim to develop a near infrared emission OLED which is rare according to the published literatures.;Here, we have successfully firstly characterized a series of porphyrin derivatives based devices by evaporation with other small molecules. The available evidence suggests that [Yb(TPP)(LOMe)] complexes and Pt{(Ph3-N)-TPP} act not only as the emitter, but also the charge transport layer in the devices. To address this issue, different substituted TPP complexes were synthesized to examine the electroluminescence properties of these complexes.;A highly efficient and stable sky blue OLED based on our newly designed sky blue emitter, BUBD-1, has been developed. It is among the best fluorescent sky blue OLEDs published in the literatures, achieving an EL efficiency of 13.2 cd/A at 20 mA/cm2 with CIEx,y (0.16, 0.30) and a t1/2 of 1815 h at L 0 = 2640 cd/m2. Based on the analysis of this result, we have fabricated a two-element fluorescent white light OLED with the benefits of BUBD-1. The device achieved an EL efficiency of 17.1 cd/A at 20 mA/cm2. Unlike common white light OLEDs, the device has a stable color and a half-decay with driving conditions. It is among the best ever reported for fluorescent emitters based WOLEDs and represents a significant breakthrough towards the realization of commercial WOLEDs.;Moreover, another highly efficient WOLED with a single novel emitting material BUBH-3 in a trilayer device structure has been developed. The device achieved an EL efficiency of 7.0 cd/A and 3.17 m/W at 6.9 V with CIE x,y (0.31, 0.36). The current efficiency of this trilayer device is among the best ever reported in the literature for any WOLED based on a single emitting material without dopant.;The last but not the least, we have developed a novel electrons transport layer, namely, MADN doped with CsF. MADN is used firstly as holes transport material with the benefit of its ambipolar property. Based on this newly developed electrons transport layer and holes transport layer, a highly efficient fluorescent green OLED has been achieved as well. |
