Determination of electron and hole mobility of regioregular poly(3-hexylthiophene) by the time of flight method

Time of flight method (TOF) is used to measure the electron and hole mobility of a spin coated regioregular poly(3-hexylthiophene) (P3HT) film. We find that both electron and hole have the same mobility (about 3.8 similar to 3.9 x 10(-4) cm(2)/Vs) at an applied field of 120 kV/cm. It is demonstrated in this paper that the electron-hole recombination process may prevent the electron transport in the material due to the fact that the carrier recombination time is much shorter than the transit time.