Fig. 24 (a) ED pattern of as-cast and rubbed layers of P3HT (M w ¼ 17.2 kg/mol) with increasing
number of rubbing cycles [100]. For all patterns, the rubbing direction is oriented in the vertical
direction. Each rubbing step is defined by a rubbing length of l ¼ 50 cm. (b) Polarized absorption
spectrum of a rubbed layer of P3HT (M w ¼ 17.2 kg/mol). The incident light is polarized parallel
(II) and perpendicular (⊥) to the rubbing direction. (c) Evolution of the dichroic ratio measured at
550 nm as function of number of rubbing steps for different molecular weights ranging from 5.8 to
70 kg/mol. The inset displays the highest dichroic ratio measured for rubbed layers of P3HT of
different molecular weight. (Reprinted with permission from Hartmann et al. [100]. Copyright
(2011) Wiley-VCH)
Morphology of P3HT in Thin Films
73
number of rubbing cycles [100]. For all patterns, the rubbing direction is oriented in the vertical
direction. Each rubbing step is defined by a rubbing length of l ¼ 50 cm. (b) Polarized absorption
spectrum of a rubbed layer of P3HT (M w ¼ 17.2 kg/mol). The incident light is polarized parallel
(II) and perpendicular (⊥) to the rubbing direction. (c) Evolution of the dichroic ratio measured at
550 nm as function of number of rubbing steps for different molecular weights ranging from 5.8 to
70 kg/mol. The inset displays the highest dichroic ratio measured for rubbed layers of P3HT of
different molecular weight. (Reprinted with permission from Hartmann et al. [100]. Copyright
(2011) Wiley-VCH)
Morphology of P3HT in Thin Films
73