Photoinduced charge transport in polymer field effect transistors

Organic/polymer field effect transistors (FETs) based on poly(3- alkylthiophenes) (P3ATs) demonstrate substantial changes upon photoexcitation. The photogeneration of charge carriers and carrier transport in these FETs were studied using the transient and modulation techniques, along with the spectral responses. It is observed that the photoinduced charge carrier generation depends on the gate voltage, light intensity and temperature, while the transport characteristics are controlled by the carrier mobility and factors influencing the local built-in electric field parameters. A prominent feature in the photoinduced effect is the slow relaxation of photocurrent upon switching off the photoexcitation