Single wall carbon nanotube (SWNT) based field effect transistors (FET) coated with semiconducting polymers respond to photoexcitation revealing characteristic features which depend on the electronic structure of the polymer. The authors observe a decrease in the drain source current of the SWNTFET in the accumulation mode in an environment of acceptor type polymer network, and a significant increase in the current in the depletion mode for a donor type polymer network around the nanotube. © 2007 American Institute of Physics.