Study on the properties of PVK/C-60 composite films with photoinduced charge transfer

We report the photovoltaic response of composite films formed with poly(N-v ingcarbazde)(PVK) and fullerene C-60 by using the physical jet deposition t echnique. The steady and transient photovoltage (PV) data were obtained for five kinds of photocells formed between ITO and aluminum electrodes. We fo und the PV signal of PVK/C-60 two-layer composite structure is enhanced by five orders of magnitude compared with those of single layer of pure PVK an d its mixed (with C-60) films. The experiments demonstrated that the signif icant enhancement of PV signal of two-layer composite films is attributed t o the efficient charge separation at the interface of PVK/C-60, which resul ts from photoinduced electron transfer from PVK to C-60 Transient PV respon se of two-layer PVK/C-60 film shows that the photoinduced electron transfer between PVK and C-60 molecules is a very fast mechanism of charge separati on.