Hole mobility enhancement of MEH-PPV film by heat treatment at Tg
Daisuke Kajiya,
Tomoyuki Koganezawa,
Ken-ichi Saitow
Affiliations
Daisuke Kajiya
Natural Science Center for Basic Research and Development (N-BARD), Hiroshima University, 1-3-1 Kagamiyama, Higashi-hiroshima, Hiroshima 739-8526, Japan
Tomoyuki Koganezawa
Japan Synchrotron Radiation Research Institute, 1-1-1, Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
Ken-ichi Saitow
Natural Science Center for Basic Research and Development (N-BARD), Hiroshima University, 1-3-1 Kagamiyama, Higashi-hiroshima, Hiroshima 739-8526, Japan
The hole mobility of poly[2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylene vinylene] (MEH-PPV) film was measured using the time-of-flight method. The hole mobility was enhanced 4-fold after annealing at around the glass transition temperature (Tg). Optical, atomic force, and Kelvin force microscopies, and grazing-incidence X-ray diffraction measurements indicate the enhancement can be attributed to a homogeneous film structure, a homogeneous Fermi level energy, and a face-on oriented structure, all of which were established by annealing at Tg.
