Injection, transport, absorption and phosphorescence properties of a series of blue-emitting Ir(III) emitters in OLEDs: a DFT and time-dependent DFT study.
Quantum-chemistry methods were explored to investigate the electronic structures, injection and transport properties, absorption and phosphorescence mechanism of a series of blue-emitting Ir(III) complexes {[(F(2)-ppy)(2)Ir(pta -X/pyN4)], where F(2)-ppy = (2,4-difluoro)phenylpyridine; pta = pyridine-1,2,4-triazole; X = phenyl(1); p-tolyl (2); 2,6-difluororophenyl (3); -CF(3) (4), and pyN4 = pyridine-1,2,4-tetrazolate (5)}, which are used as emitters in organic light-emitting diodes (OLEDs). The mobility of hole and electron were studied computationally based on the Marcus theory. Calculations of Ionization potentials (IPs) and electron affinities (EAs) were used to evaluate the injection abilities of holes and electrons into these complexes. The reasons for the lower EL efficiency and phosphorescence quantum yields in 3-5 than in 1and 2 have been investigated. These new structure-property relationships can guide an improved design and optimization of OLED devices based on blue-emitting phosphorescent Ir(III) complexes.
Li
Xiao-Na
XN
State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China.
Wu
Zhi-Jian
ZJ
Si
Zhen-Jun
ZJ
Zhang
Hong-Jie
HJ
Zhou
Liang
L
Liu
Xiao-Juan
XJ
D000042:Absorption; D003116:Color; D004566:Electrodes; D004579:Electron Transport; D004583:Electrons; D007267:Injections; D007495:Iridium / Q000737:chemistry*; D008027:Light; D008163:Luminescent Measurements; D008752:Methylene Chloride / Q000737:chemistry; D008958:Models, Molecular; D008968:Molecular Conformation; D009942:Organometallic Compounds / Q000737:chemistry*; D011789:Quantum Theory; D013329:Structure-Activity Relationship; D013997:Time Factors
D009942:Organometallic Compounds; D007495:Iridium; D008752:Methylene Chloride