Nanoscale optical and photoresponsive electrical properties of P3HT and PCBM composite nanowires

In this paper, we report on the fabrication, intrinsic characteristics, and photoresponsive electrical properties of heterojunction composite nanowires (NWs) consisting of p-type poly (3-hexylthiophene) (P3HT) and n-type [6,6]-phenyl C-61 butyric acid methyl ester (PCBM). The P3HT:PCBM heterojunction composite NWs were prepared through a wetting method based on an alumina nanoporous template. The nanoscale optical and structural properties of the single NW were investigated using laser confocal microscope Raman and photoluminescence spectra. The photoresponsive current-voltage (I-V) characteristics of the P3HT:PCBM single NW were measured by means of Au-Al electrode patterns. For the P3HT: PCBM single NW, the I-V characteristics in the dark condition showed diode-like behaviors due to the formation of energy barriers. Under light illumination, the current level of the P3HT:PCBM single NW was enhanced at a relatively high applied bias (>= 10 V). The photovoltaic effect was observed for the solar cells using P3HT:PCBM composite NWs and the maximum power conversion efficiency was estimated to be 0.14%. (C) 2011 Elsevier B.V. All rights reserved.