Abstract
Abstract The thesis includes three parts that focuses on synthesizing various red and green phosphorescent iridium complexes. In the first part, the alkenylquinoline and alkenylisoquinoline derivatives were prepared by two different procedures. The iridium(III) complex cyclometalated with alkenylquinoline or alkenylisoquinoline ligangs as red-light emitters for OLED application. Those complexes show deep red phosphorescent emissions. The optimed device structure is NPB(10nm)/TCTA(20nm)/Dopants(5%):CBP(or o-CzOXD)(30nm)/BCP (10nm)/Alq(50nm)/LiF(1nm)/Al(100nm). When E-(PPIQ)2Ir(acac) (5%) was the emitter doped in the o-CzOXD layer, the device gave saturated red light with the emission maximum at 630 nm and show a turn-on voltage of 3.5 V, the maximum external quantum efficiency of 17.5% at 4.5 V, a current efficiency of 15.1cd/A, and a power efficiency of 11.7lm/W at 4.0 V, a maximum brightness of 24218cd/m2 at 15.0 V. The (CIE) coordinates calculated based on the EL data at 6 V are (0.68, 0.31). In the second part, a series of phosphorescent iridium(III) complexes with nonconjugated 1-benzylisoqunoline ligand were synthesized. The methylene spacer of the cyclometalated 1-benzylisoqunoline ligand effectively interrupts the □conjugation between the phenyl and isoquinoline moieties. The optimized device structure is NPB(10nm)/TCTA(20nm)/Dopants(5%):CBP(oro-CzOXD)(30nm)/BCP (10nm)/Alq(50nm)/LiF(1nm)/Al(100nm). When (bziq)2Ir(acac)(5%) was used the dopant emitter in the CBP layer, the device show the emission maximum at 546 nm and a turn-on voltage of 3.1 V, an external quantum efficiency of 18.7% at 4.5 V, a current efficiency of 70.5cd/A, and a power efficiency of 56.3lm/W at 3.5 V, a maximum brightness of 62059cd/m2 at 16.0V. The (CIE) coordinates calculated based on the EL data at 6 V are (0.39, 0.58). In the third part, a new series of iridium(III) complexes with cyclometalated dibenzo[h,f]quinoline(DBQ) ligands with having a rigid conjugation were systemic synthesis. The iridium complexes with methylation show green phosphorescent emissions(530~536nm). The best device structure is NPB(20nm)/TCTA(10nm)/(4mDBQ)2Ir(acac)(5%): CBP(30nm)/BCP(10nm)/Alq(50nm)/LiF(1nm)/Al(100nm). The device show the emission maximum at 518 nm and a turn-on voltage of 3.1 V, an external quantum efficiency of 24.0% at 5.0 V, a current efficiency of 92.4cd/A, and a power efficiency of 74.1lm/W at 3.5 V, a maximum brightness of 186093cd/m2 at 13.0 V. The (CIE) coordinates calculated based on the EL data at 6 V are (0.27, 0.66). An excellent dopant for green phosphorescent OLEDs.