Article pubs.acs.org/JPCC
Dispersion-Process Effects on the Photoluminescence Quantum Yields of Single-Walled Carbon Nanotubes Dispersed Using Aromatic Polymers Shinichiro Mouri,*,† Yuhei Miyauchi,†,‡ and Kazunari Matsuda*,† †
Institute of Advanced Energy, Kyoto University, Uji, Kyoto 611-0011, Japan Japan Science and Technology Agency, PRESTO, 4-1-8 Honcho Kawaguchi, Saitama 332-0012, Japan
‡
S Supporting Information *
ABSTRACT: We studied the dispersion-process effects on the photoluminescence (PL) properties of single-walled carbon nanotubes (SWNTs) dispersed using poly[9,9-dioctylfluorenyl-2,7-diyl] (PFO) (PFO-SWNTs). The difference of the synthesis method (CoMoCAT, HiPco, and alcohol chemical vapor deposition) is insignificant for the PL quantum yields (QYs) of PFO-SWNTs. SWNTs processed using a moderate bath-type sonicator showed the maximum PL QY (∼2%) and the QY decreased drastically due to ultrasonic dispersion using a vigorous tip-type sonicator. The very low density of exciton quenching sites ( ∼20 cm2s−1, the calculated exciton diffusion length (∼1 μm) exceeds the average nanotube length (L ≈ 500 nm). Therefore, a diffusion constant of D ≈ 10 cm2 s−1 with a small defect density (
