| Summary: | 碩士 === 國立清華大學 === 材料科學工程學系 === 100 === We demonstrate in this report a novel wet- and dry-process feasible green bis[5-methyl-8-trifluoromethyl-5H-benzo(c)(1,5)naphthyridin-6- one]iridium(picolinate) (3-CF3BNO) containing Organic light-emitting diode (OLED) device with an efficacy roll-up character. The newly synthesized iridium complex exhibits a relatively short excited-state lifetime (0.39 μs) and a high quantum yield of 74%, both which warrant this complex to be a highly electroluminescence active candidate as long as a proper device structure is coupled.
The wet processed device using a 3,5-di(9H-carbazol-9-yl) tetraphenylsilane (SimCP2) host, for example, shows a 52 lm/W with an 18% external quantum efficiency (EQE) at 100 cd/m2, which increases to 61 lm/W with a 23% EQE at 1,000 cd/m2, the highest among all reported wet-processed green OLEDs. Based on the same device structure, the green tris(2-phenylpyridine) iridium(III) (Ir(ppy)3) containing counterpart exhibits only a 12 lm/W with a 6% EQE at 1,000 cd/m2. For the dry-processed device using a 4,4-bis(carbazol-9-yl)biphenyl (CBP) host, it is 59 lm/W with a 25% EQE at 1,000 cd/m2, while the counterpart of the green Ir(ppy)3 exhibits only 25 lm/W with a 5% EQE. These comparisons also demonstrate this green 3-CF3BNO emitter to possess a potential to yield an even higher device efficacy provided more appropriate hosting, co-hosting, carrier transporting, and/or carrier confining materials are employed.
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