Photocurrents in double-layer organic field-effect transistors

Photogenerated carriers in active double-layer 3,4,9,10-perylenetetracarboxylic dianhydride/copper phthalocyanine (PTCDA/CuPc) organic field-effect transistor (OFET) has been investigated. The PTCDA and CuPc layers have n- and p-type conductivities, respectively; thus, PTCDA can be assumed as an acceptor and CuPc as a donor in the meaning of photovoltaic device. It has been found that the charges are generated in the bulk of the organic material rather than close to the organic-organic interface.