Enhanced photovoltaic response of PVK/C-60 composite films

We report the photovoltaic response of composite films formed with polymer PVK and fullerene C-60 by Using the physical jet deposition technique. The steady and transient photovoltage (PV) data were obtained for five kinds of photocells formed between ITO and aluminum electrodes. We found that the P V signal of PVK/C-60 two-layer composite structure is enhanced by five orde rs of magnitude compared to that of single layer of pure PVK or its mixed ( with CAO) films. The experiments demonstrated that the significant enhancem ent of PV signal of two-layer composite films is attributed to the efficien t charge separation at the interface of PVK/C-60 which results from photoin duced electron transfer from PVK to C-60. The transient PV response of a tw o-layer PVK/C-60 film shows that the photoinduced electron transfer between PVK and C-60 molecules is a very fast mechanism of charge separation. (C) 2000 Elsevier Science B.V, All rights reserved.