Table of Contents
ISRN Renewable Energy
Volume 2012 (2012), Article ID 385415, 8 pages
http://dx.doi.org/10.5402/2012/385415
Research Article

Investigation of PCBM Concentration on the Performance of Small Organic Solar Cell

1Department of Physics, Faculty of Science, Al-Azhar University, Assiut 71121, Egypt
2Department of Frontier Materials, Nagoya Institute of Technology, Nagoya 466-8555, Japan

Received 10 April 2012; Accepted 15 July 2012

Academic Editors: F. E. Little and P. Poggi

Copyright © 2012 Yasser A. M. Ismail et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

We have fabricated bulk heterojunction organic solar cells using coumarin 6 (C6) as a small organic dye, for light harvesting and electron donating, with fullerene derivative [6,6]-phenyl-C61 butyric acid methyl ester (PCBM), acting as an electron acceptor, by spin-coating technique of the blend solutions. We have studied effect of PCBM concentration on photocurrent and performance parameters of the solar cells. We found that the optical absorption of the dye increased with increasing its concentration in the active layer blends. The higher concentrations of PCBM in active layer enhanced the photocurrent of the solar cells, as a result of improving charge carrier separation and electron transport in solar cell active layer. The improved charge carrier separation between C6, as a donor, and PCBM, as an acceptor, was indicated through the formation of bulk heterojunction by blending C6 with PCBM. The formation of C6:PCBM bulk heterojunction blend was confirmed through the symbatic behavior of the corresponding solar cell and, also, through the homogeneity and smoothing in the atomic force microscopy images of the C6:PCBM blend films. For the same reasons, the performance parameters of the C6:PCBM solar cell improved by modification of the PCBM concentration in the solar cell active layer.