Effects of P3HT concentration on the performance of organic field effect transistors

Abstract:

Top-contact organic field effect transistors (OFETs) based on poly(3-hexylthiophene) (P3HT) with different concentrations in chloroform (CHCl₃) are fabricated. The output characteristics indicate that the P3HT concentration has significant influence on the OFET devices. The performance of the devices firstly is enhanced with increasing the P3HT concentration, and then decreases. The optimized devices with the P3HT concentration of 2 mg/mL show the best performance. The field0effect mobility is up to 1.4×10⁻² cm²/Vs, the threshold voltage (V _t) is as low as −20 V, and the current on/off ratio (I _on/off) is close to the order of 10⁴. The results suggest that the P3HT aggregation patterns induced by different concentrations can improve the performance of the OFETs.