Photodegradation Dynamics of Polyfluorene Thin Films Studied by Means of Photoluminescence Spectroscopy
The photodegradation dynamics of a polyfluorene (PFO) derivative has been investigated by photoluminescence (PL) spectroscopy. PFO shows promise as an efficient blue emitter for organic lightemitting diodes, but the color purity of its PL is unstable under UV irradiation in air. Under these conditions, fluorene units are easily oxidized and the oxidized units, i.e., fluorenone, exhibit a new green emission band (Gband). By examining the temporal evolution of the exciton emission and G-band, we have found that the photodegradation of PFO consists of three stages with characteristic time constants of 1.8, 27, and 130 min under UV irradiation with an intensity of 1.6 mW/cm2.In the first stage, fluorene units are rapidly oxidized into fluorenone, and in the second, efficient energy transfer from fluorene units to fluorenone units slows the oxidation of fluorene. In the last stage, fluorenone units are further oxidized with a much longer degradation time constant. This degradation dynamics is independent of the conformation of PFO chains.
Masanori Nakagawa Takashi Kobayashi Takashi Nagase Hiroyoshi Naito
Department of Physics and Electronics, Osaka Prefecture University,1-1 Gakuen-cho, Naka-ku, Sakai 59 Department of Physics and Electronics, Osaka Prefecture University,1-1 Gakuen-cho, Naka-ku, Sakai 59 Department of Physics and Electronics, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai 5
国际会议
The 31st International Congress on Imaging Science(第31届国际影像科学大会 ICIS2010)
北京
英文
775-778
2010-05-12（万方平台首次上网日期，不代表论文的发表时间）