Soluble and processable regioregular poly(3-hexylthiophene) for thin film field-effect transistor applications with high mobility

TLDR

Field‑effect transistors made from solution‑cast regioregular poly(3‑hexylthiophene) display significant electrical characteristics. The study shows that such films can achieve field‑effect mobilities of 0.045 cm²/Vs (accumulation) and 0.01 cm²/Vs (depletion) with on/off ratios exceeding 10³, and that solvent choice and post‑treatment with ammonia or 100 °C N₂ annealing enhance device performance.

Abstract

The electrical characteristics of field-effect transistors using solution cast regioregular poly(3-hexylthiophene) are discussed. We demonstrate that both high field-effect mobilities (ca. 0.045 cm2/V s in the accumulation mode and 0.01 cm2/V s in the depletion mode), and relatively high on/off current ratios (greater than 103) can be achieved. We find that the film quality and field-effect mobility are strongly dependent on the choice of solvents. In addition, treating a film with ammonia or heating to 100 °C under N2 can increase the on/off ratio without decreasing the mobility.