| 초록 |
We report the effect of incorporating chalcogenophene comonomers, namely furan (Fu), thiophene (Th), and selenophene (Se), in cyclopentadithiophene(CDT)-based polymers on their optoelectrical properties for organic field-effect transistors (OFETs). The optical, electrical, and morphological properties of these polymers are investigated. Compared to the other polymers, the Th-polymer showed the highest crystallinity with the lowest π-π stacking distance (dπ-π ≈ 3.58 Å) and the highest crystalline length (Lc ≈ 40 Å), confirmed by two-dimensional grazing incidence wide-angle X-ray diffraction (2D GIWAXD). However, the highest hole mobility was obtained from the Se-polymers (μ = 0.25 cm2/V-s), which is higher than Fu-polymer (μ = 0.06 cm2/V-s) and Th-polymer (μ = 0.20 cm2/V-s). We attribute lower mobility of Th-polymer to its island-like crystalline domains confirmed by atomic force microscopy results. Our results suggest a new design rule for developing high-mobility π-conjugated polymers.Keywords: semiconducting polymers, comonomer substitution, chalcogenophene, benzothiadiazole, organic field-effect transistors |
