S-Space College of Engineering/Engineering Practice School (공과대학/대학원) Dept. of Material Science and Engineering (재료공학부) Journal Papers (저널논문_재료공학부)
Highly efficient light-harvesting system based on a phosphorescent acceptor coupled with dendrimer donors via singlet-singlet and triplet-triplet energy transfer
- Kwon, Tae-Hyuk; Kim, Myoung Ki; Kwon, Jongchul; Shin, Dae-Yup; Park, Su Jin; Lee, Chang-Lyoul; Kim, Jang-Joo; Hong, Jong-In
- Issue Date
- American Chemical Society
- Chem. Mater. 2007, 19, 3673
- A series of efficient light-harvesting systems (FIr3mGx, x = 1−3) based on dendrimer donor (mCP: N,N-dicarbazolyl-3,5-benzene) derivatives coupled with a sky blue phosphorescent acceptor (FIrpic: iridium(III) bis[(4,6-difluorophenyl)pyridinato-N,C2]-3-hydroxypicolinate derivative) were prepared, and their photophysical properties were investigated. The light-harvesting ability of FIr3mGx (x = 1−3) increases with the number of energy donor mCP units. The acceptor PL intensity of the donor−acceptor conjugate dendrimers (FIr3mGx, x = 1−3) increases over 6 times with the number of mCP units via sensitization from the light-harvesting antenna after excitation at the donor absorption (λex = 310 nm), as compared to that of only an acceptor without a donor (FIrpic) upon excitation at the MLCT region (λex = 380 nm) because of efficient intramolecular singlet−singlet and triplet−triplet energy transfer from the donor to the acceptor and less luminance quenching induced by the bulky dendrimer structure. The singlet−singlet intramolecular energy transfer in FIr3mGx from the dendrimer donor to the acceptor exhibits a high efficiency of greater than 90% via the steady-state PL method and 94% via the transient PL method. Additionally, the triplet−triplet energy transfer efficiency via the transient PL method exhibits an efficiency greater than 99%. This indicates that FIr3mGx exhibits good light-harvesting abilities because the mCP unit is an efficient light absorber and because the core FIrpic functions as a spatial energy concentrator that drains energy from the dendrimer donor.
- 0897-4756 (print)
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