By connecting tercarbazole(3 Cz)and triphenyltriazine(TRz)units with a diphenyl ether group,we designed and synthesized a new donor-spacer-acceptor structure molecule9’-(4-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenoxy)...By connecting tercarbazole(3 Cz)and triphenyltriazine(TRz)units with a diphenyl ether group,we designed and synthesized a new donor-spacer-acceptor structure molecule9’-(4-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenoxy)phenyl)-9’H-9,3’:6’,9"-tercarbazole(3 Cz-o-TRz)as the multifunctional component of exciplex emitters.As expected,the intermolecular charge-transfer transition is dominant for3 Cz-o-TRz because of the space-enough and conjugation-forbidden linkage of the diphenyl ether group,increasing the intrinsic characteristics of the 3 Cz and TRz moieties in its single-molecule state.Accordingly,three common electron acceptors(4,6-bis(3,5-di(pyridin-3-yl)phenyl)-2-methylpyrimidine(B3 PyMPm),4,6-bis(3,5-di(pyridin-4-yl)phenyl)-2-methylpyrimidine(B4 PyMPm),and(1,3,5-triazine-2,4,6-triyl)tris(benzene-3,1-diyl)tris(diphenylphosphineoxide)(POT2 T))and three common electron donors(4,4’-(cyclohexane-1,1-diyl)bis(N,N-di-p-tolylaniline)(TAPC),tris(4-(10 H-phenoxazin-10-yl)phenyl)amine(TPA-PXZ),and N1-phenyl-N4,N4-bis(4-(phenyl(m-tolyl)amino)phenyl)-N1-(m-tolyl)benzene-1,4-diamine(m-MTDATA))were chosen to construct six exciplex emitters with 3 Cz-o-TRz.In the organic light-emitting diodes(OLEDs),the emission spectra of these exciplex emitters could be gradually modulated from 510 to 590 nm.In addition,TAPC:3 Cz-o-TRz-and 3 Cz-o-TRz:PO-T2 T-based OLEDs achieved desirable performance with maximum external quantum efficiencies(EQEs)around 12%.Moreover,a simple tandem OLED containing TAPC:3 Cz-o-TRz and 3 Czo-TRz:PO-T2 T emitters realized optimal performance with an ultralow turn-on voltage of 2.4 V and a maximum EQE of14.1%.These results indicate the great potential of the donorspacer-acceptor structure compounds in developing exciplex emitters.展开更多
基金supported by the National Natural Science Foundation of China(62175262)the Fundamental Research Funds for the Central Universities(2020CX021)the Key R&D plan of Hunan Province(2022SK2101)。
基金supported by the National Natural Science Foundation of China(51773029,52073040,51533005 and 51821002)the Fundamental Research Funds for the Central Universities(ZYGX2016Z010)the International Cooperation and Exchange Project of Science and Technology Department of Sichuan Province(2019YFH0057 and 2019YFH0059)。
文摘By connecting tercarbazole(3 Cz)and triphenyltriazine(TRz)units with a diphenyl ether group,we designed and synthesized a new donor-spacer-acceptor structure molecule9’-(4-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenoxy)phenyl)-9’H-9,3’:6’,9"-tercarbazole(3 Cz-o-TRz)as the multifunctional component of exciplex emitters.As expected,the intermolecular charge-transfer transition is dominant for3 Cz-o-TRz because of the space-enough and conjugation-forbidden linkage of the diphenyl ether group,increasing the intrinsic characteristics of the 3 Cz and TRz moieties in its single-molecule state.Accordingly,three common electron acceptors(4,6-bis(3,5-di(pyridin-3-yl)phenyl)-2-methylpyrimidine(B3 PyMPm),4,6-bis(3,5-di(pyridin-4-yl)phenyl)-2-methylpyrimidine(B4 PyMPm),and(1,3,5-triazine-2,4,6-triyl)tris(benzene-3,1-diyl)tris(diphenylphosphineoxide)(POT2 T))and three common electron donors(4,4’-(cyclohexane-1,1-diyl)bis(N,N-di-p-tolylaniline)(TAPC),tris(4-(10 H-phenoxazin-10-yl)phenyl)amine(TPA-PXZ),and N1-phenyl-N4,N4-bis(4-(phenyl(m-tolyl)amino)phenyl)-N1-(m-tolyl)benzene-1,4-diamine(m-MTDATA))were chosen to construct six exciplex emitters with 3 Cz-o-TRz.In the organic light-emitting diodes(OLEDs),the emission spectra of these exciplex emitters could be gradually modulated from 510 to 590 nm.In addition,TAPC:3 Cz-o-TRz-and 3 Cz-o-TRz:PO-T2 T-based OLEDs achieved desirable performance with maximum external quantum efficiencies(EQEs)around 12%.Moreover,a simple tandem OLED containing TAPC:3 Cz-o-TRz and 3 Czo-TRz:PO-T2 T emitters realized optimal performance with an ultralow turn-on voltage of 2.4 V and a maximum EQE of14.1%.These results indicate the great potential of the donorspacer-acceptor structure compounds in developing exciplex emitters.
