Intramolecular energy transfer between the triplet of ancillary ligand and the metal to ligand charge transfer state existed in heterocyclometalated iridium (III) complexes

Han, Liangliang; Yang, Dongfang; Li, Wenlian; Chu, Bei; Chen, Yiren; Su, Zisheng; Zhang, Dongyu; Yan, Fei; Wu, Shuanghong; Wang, Junbo; Hu, Zhizhi; Zhang, Zhiqiang
April 2009
Applied Physics Letters;4/20/2009, Vol. 94 Issue 16, p163303
Academic Journal
Higher efficiency red organic light emitting devices (OLEDs) were obtained by employing Ir (III) complexes with 1-phenylbutane-1, 3-dione (ba) as the second ligand than that with acetylacetone (acac) as the second ligand, which were attributed to the intramolecular energy transfer existed in these complexes. The reason were attributed to the intramolecular energy transfer existed in these complexes and were approved by their photoluminescence characteristics at 77 K, as well the phosphorescence decay lifetime. Because of the lower triplet energy level of ba (Tba,19 230 cm-1) whose energy was suitable to transfer to the triplet of the metal to ligand charge transfer (MLCT) (3MLCT,16 260 cm-1) state compared to Tacac (25 500 cm-1), more efficient OLEDs were obtained (7.0 cd/A) using Ir[2-(4′-methanoxy-styryl)-benzothiazole]2ba (ba-2) than Ir[2-(4′-methanoxy-styryl)-benzothiazole]2acac acac-2 (6.1 cd/A).


Related Articles

  • Intramolecular energy transfer in heteroleptic red phosphorescent dopants. Jun Yeob Lee // Applied Physics Letters;11/27/2006, Vol. 89 Issue 22, p223517 

    Intramolecular energy transfer in heteroleptic red phosphorescent dopant materials with mixed ligand units in one molecule was studied. 1-phenylisoquinoline (piq) and phenylpyridine (ppy) moieties were introduced as ligands for Ir based phosphorescent dopants and light emission mechanism was...

  • Excitation mechanism in polymer layers doped with tetra-methylester of perylene tetracarboxylicacid: influences of doping concentration and external bias. Li-Gong Yang; Xu Liu; Pei-Fu Gu; Mang Wang; Hong-Zheng Chen // Applied Physics A: Materials Science & Processing;May2009, Vol. 95 Issue 2, p547 

    A spin-coated layer of poly( N-vinylcarbazole) (PVK) doped with tetra-methyl ester of perylene-3,4,9,10-tetracarboxylicacid (TMEP) is prepared, and the effects of dopant concentration and bias voltages on excitation mechanisms are studied through analyzing its emission characteristics. The...

  • Detailed studies on energy loss mechanism in phosphor-sensitized fluorescent polymer light-emitting devices. Ye, Tengling; Shao, Shiyang; Chen, Jiangshan; Chen, Zhenyu; Wang, Lixiang; Ma, Dongge // Journal of Applied Physics;Mar2010, Vol. 107 Issue 5, p054515-1 

    We studied the main energy loss mechanism in electroluminescent (EL) processes in phosphor-sensitized fluorescent polymer light-emitting devices. The used organometallic phosphor is fac-tris(2-phenyl-pridine) iridium [Ir(ppy)3] and the used red fluorescent dye is...

  • Electro-active colorants - some developments. Sekar, N. // Colourage;Aug2011, Vol. 58 Issue 8, p58 

    The article offers information related to the developments in electro-active colorants. It states that research shows that obtaining highly efficient blue phosphorescence can be made by increasing the contribution of metal-to-ligand charge transfer (MLCT) at low-lying triplet manifold. It adds...

  • Enhanced electrophosphorescence via highly efficient energy transfer from conjugated polymer. Kim, Tae-Ho; Yoo, Dong-Hee; Park, Jong Hyeok; Park, O. Ok; Yu, Jae-Woong; Kim, Jai Kyeong // Applied Physics Letters;4/25/2005, Vol. 86 Issue 17, p171108 

    We have demonstrated that efficient green electrophosphorescence is obtained via cascade energy transfer from poly(N-vinylcarbazole) (PVK) and host fluorescent polymer to the phosphorescent iridium complex. Efficient energy transfers from PVK to fluorescent polymer and then from this host...

  • Enhanced electrophosphorescence of copper complex based devices by codoping an iridium complex. Su, Zisheng; Li, Wenlian; Che, Guangbo; Xu, Maoliang; Kong, Zhiguo; Wang, Dan; Xin, Qi; Han, Liangliang; Chu, Bei; Bi, Defeng // Applied Physics Letters;4/2/2007, Vol. 90 Issue 14, p143505 

    Evidently enhanced electrophosphorescence of [Cu(bis[2-(diphenylphosphino)phenyl] ether)(6,7-dicyanodipyrido [2,2-d:2′,3′-f] quinoxaline)] BF4 (CuI complex) by codoping bis[(4,6-difluorophenyl)-pyridinato-N, C2](picolinato)Ir(III) (FIrpic) into the same host,...

  • Photophysical Properties of Highly Efficient Blue-Green Emitting Cationic Iridium (III) Complexes Containing Two 2-Phenylbenzothiazole Ligands and One Diphosphine Ligand. Seong-Jae Yun; Young-Kwang Song; Minji Kim; Jaemin Shin; Sung-Ho Jin; Sung Kwon Kang; Young-Inn Kim // Bulletin of the Korean Chemical Society;2014, Vol. 35 Issue 11, p3199 

    Two novel phosphorescent heteroleptic cationic Ir(III) complexes, Ir(bt)2(dmpe) (Ir1) and Ir (bt)2(dppe) (Ir2), where bt is 2-phenylbenzothiazole, dmpe is 1,2-bis(dimethylphosphino)ethane, and dppe is 1,2-bis(diphenylphosphino) ethane, were designed and synthesized. Their photophysical and...

  • Role of electronic localization in the phosphorescence of iridium sensitizing dyes. Himmetoglu, Burak; Marchenko, Alex; Dabo, Ismaïla; Cococcioni, Matteo // Journal of Chemical Physics;10/21/2012, Vol. 137 Issue 15, p154309 

    In this work we present a systematic study of three representative iridium dyes, namely, Ir(ppy)3, FIrpic, and PQIr, which are commonly used as sensitizers in organic optoelectronic devices. We show that electronic correlations play a crucial role in determining the excited-state energies in...

  • Efficiency Control in Iridium Complex-Based Phosphorescent Light-Emitting Diodes. Boucar Diouf; Woo Sik Jeon; Ramchandra Pode; Jang Hyuk Kwon // Advances in Materials Science & Engineering;2012, p1 

    Key factors to control the efficiency in iridium doped red and green phosphorescent light emitting diodes (PhOLEDs) are discussed in this review: exciton confinement, charge trapping, dopant concentration and dopant molecular structure. They are not independent from each other but we attempt to...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics