| Abstract: | A serial of poly(3‐alkylthiophene)s with different alkyl chains substituted at 3‐position (3‐Cn‐PTs) was synthesized. The long‐chain alkyl group would enhance not only the processability but also the luminescence efficiency. The synthesized polymers were highly soluble in common organic solvents. The weight‐average molecular weights of the resulting polymers were in the range of 7 900–100 300 g/mol with molecular polydispersity indexes in the range of 1.88–8.70. The decomposition temperatures were in the range of 357.8–450.6°C determined by thermogravimetry analysis. A quasi‐reversible and stable electrochemical behavior for these polymers was observed in the oxidation process. The highest occupied molecular orbital, lowest unoccupied molecular orbital energy levels and band gaps were estimated by electrochemical as well as optical measurements. The UV‐Vis absorption spectra of the present polymers showed absorption bands around 400–427.5 nm in solution and 430–490 nm as thin solid films. The photoluminescence spectra showed strong light emission at ˜520 nm in chloroform and at ˜560–580 nm as thin solid film. Yellow‐orange light emission from the light‐emitting diodes with the structure of Indium‐tin oxide/poly(N‐vinylcarbazole)/3‐Cn‐PTs/Al using the polymers as the active emissive layers was achieved. |
