Thin Solid Films, Vol.517, No.9, 2988-2993, 2009
Photoinduced charge transfer through films containing poly(hexylthiophene), phthalocyanine, and porphyrin-fullerene layers
Efficient photoinduced interlayer electron transfer from a phthalocyanine derivative, ZnPH4, to porphyrin cation of a porphyrin-fullerene donor-acceptor dyad was demonstrated by using time-resolved photovoltage technique. Multicomponent thin films with desired layer arrangements were constructed by the Langmuir-Blodgett and spin-coating methods in order to study charge transfer in solid state. As a contradiction to the photovoltage experiments, the dyad monolayer in the film structure did not enhance the current amplitude in electrochemical photocurrent measurements. This is associated with a weak electronic interaction between fullerene and aqueous electrolyte, reducing the photocurrent generation. The use of poly(3-hexylthiophene) as a hole conducting layer was shown to improve photocurrent yield of the device by forming efficient heterojunction together with the ZnPH4 layer. (C) 2008 Elsevier B.V. All rights reserved.
Keywords:Langmuir-Blodgett;Thin film;Time-resolved Maxwell displacement charge;Photovoltaic;Porphyrin-fullerene dyad;Poly(hexylthiophene);Phthalocyanine;Electron transfer