27 August 2009 Photophysical study of iridium complexes by absolute photoluminescence quantum yield measurements using an integrating sphere
Author Affiliations +
Abstract
We have developed an apparatus (Hamamatsu C9920-02) for measuring the absolute photoluminescence quantum yield. This system consists of an excitation light source, a sample holder mounted in an integrating sphere and a multi-channel CCD spectrometer. Using this apparatus, the absolute phosphorescence quantum yields were measured for several iridium complexes doped in organic thin films or dissolved in deaerated solutions. The iridium complexes fac-tris (2-phenylpyridine)iridium(III) (Ir(ppy)3) and its derivatives, showed high phosphorescence quantum yields (>90 %), while bis(2-(2'-benzo(4,5-a)thienyl)pyridinato-N,C3')iridium(III)(acetylacetonate) (Btp2Ir(acac)) gave a lower phosphorescence quantum yield (less than 40 %). To reveal the mechanism of nonradiative decay of the excited iridium complexes, we made time-resolved photoacoustic measurements. It was found that all of the iridium complexes undergo S1-T1 intersystem crossing with efficiencies of close to 100 % after photoexcitation. This indicates that the lower phosphorescence quantum yield for Btp2Ir(acac) is due to involvement of the T1-S0 intersystem crossing process.
© (2009) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Kengo Suzuki, Ayataka Endo, Toshitada Yoshihara, Seiji Tobita, Masayuki Yahiro, Daisuke Yokoyama, Chihaya Adachi, "Photophysical study of iridium complexes by absolute photoluminescence quantum yield measurements using an integrating sphere", Proc. SPIE 7415, Organic Light Emitting Materials and Devices XIII, 741504 (27 August 2009); doi: 10.1117/12.828463; https://doi.org/10.1117/12.828463
PROCEEDINGS
8 PAGES


SHARE
Back to Top