Direct Correlation Between Electric and Structural Properties During Solidification of Poly(3‐hexylthiophene) Drop‐Cast Films

Structural and electrical properties of semicrystalline P3HT cast films onto Si/SiO₂ surface are studied during the solidification under applied electric field in lateral OFET geometry. During evaporation of the solvent, the formation of P3HT crystallites is monitored simultaneously by time‐resolved X‐ray diffraction and by source‐drain current measurements. The electrical current is reaching its maximum in two pronounced regimes already before complete solidification of the polymer as detected by X‐ray diffraction intensities. The monitored complex time dependence of current and X‐ray intensities reveals a highest conducting level for the gel‐like state.