TY - JOUR
T1 - Triplet level-dependent photoluminescence and photoconduction properties of π-conjugated polymer thin films doped by iridium complexes
AU - An, Jongdeok
AU - Chang, Jungyun
AU - Han, Jungwook
AU - Im, Chan
AU - Yu, Young Jun
AU - Choi, Dong Hoon
AU - Jin, Jung Il
AU - Majima, Tetsuro
N1 - Funding Information:
This work was supported by the Seoul Research & Business Development (R & BD) Program (CR070048) and the Guest Associate Professor Program, Nanoscience and Nanotechnology Center, Institute of Scientific and Industrial Research (SANKEN), Osaka University. C.I. is indebted to Dr. Sergey Bagnich for fruitful discussions.
PY - 2008/12/15
Y1 - 2008/12/15
N2 - Triplet energy level-dependent decay pathways of excitons populated on iridium (Ir) complexes within π-conjugated polymeric matrices were studied by means of photoluminescence (PL) and photoconduction action spectroscopy. We chose a set of matrices, poly(9-vinylcarbazole) (PVK), poly[9,9-bis(2-ethylhexyl)fluorene-2,7-diyl] (PF2/6), poly [2-(5′-cyano-5′-methyl-hexyloxy)-1,4-phenylene] (CNPPP), and poly [2-(5′-cyano-5′-methyl-hexyloxy)-1,4-phenylene-co-pridine] (CNPPP-py10 and CNPPP-Py20), having triplet energy levels ranging from 2.2 up to 3.0 eV. As Ir-complex dopants, we selected three phosphorescent emitters, iridium(III)bis(2-(2′-benzothienyl) pyridinato-N-acetylacetonate) (Ir(btp)2acac), iridium(III)fac-tris(2-phenylpyridine) (Ir(ppy)3), and iridium(III)bis[(4,6-fluorophenyl)-pyridinato-N,C2′]picolinate (FIrpic), having triplet energy levels of 2.1, 2.5, and 2.7 eV, respectively. It was found that the triplet emission from the dopants, being populated via energy transfer from the matrices, was strongly dependent on the matching of triplet energy levels between matrix polymers and Ir-complexes. Photocurrent action spectra confirm effective exciton confinement at the dopants sites in the case of PVK matrix systems.
AB - Triplet energy level-dependent decay pathways of excitons populated on iridium (Ir) complexes within π-conjugated polymeric matrices were studied by means of photoluminescence (PL) and photoconduction action spectroscopy. We chose a set of matrices, poly(9-vinylcarbazole) (PVK), poly[9,9-bis(2-ethylhexyl)fluorene-2,7-diyl] (PF2/6), poly [2-(5′-cyano-5′-methyl-hexyloxy)-1,4-phenylene] (CNPPP), and poly [2-(5′-cyano-5′-methyl-hexyloxy)-1,4-phenylene-co-pridine] (CNPPP-py10 and CNPPP-Py20), having triplet energy levels ranging from 2.2 up to 3.0 eV. As Ir-complex dopants, we selected three phosphorescent emitters, iridium(III)bis(2-(2′-benzothienyl) pyridinato-N-acetylacetonate) (Ir(btp)2acac), iridium(III)fac-tris(2-phenylpyridine) (Ir(ppy)3), and iridium(III)bis[(4,6-fluorophenyl)-pyridinato-N,C2′]picolinate (FIrpic), having triplet energy levels of 2.1, 2.5, and 2.7 eV, respectively. It was found that the triplet emission from the dopants, being populated via energy transfer from the matrices, was strongly dependent on the matching of triplet energy levels between matrix polymers and Ir-complexes. Photocurrent action spectra confirm effective exciton confinement at the dopants sites in the case of PVK matrix systems.
KW - Energy transfer
KW - OLED
KW - Phosphorescence
KW - Photoluminescence
KW - π-Conjugated polymer
UR - http://www.scopus.com/inward/record.url?scp=56249135241&partnerID=8YFLogxK
U2 - 10.1016/j.jphotochem.2008.08.019
DO - 10.1016/j.jphotochem.2008.08.019
M3 - Article
AN - SCOPUS:56249135241
SN - 1010-6030
VL - 200
SP - 371
EP - 376
JO - Journal of Photochemistry and Photobiology A: Chemistry
JF - Journal of Photochemistry and Photobiology A: Chemistry
IS - 2-3
ER -