Organic Solar Cell Based on Water Soluble Pentacene

Abstract

Potential risk of conventional fuel crisis in coming few decades has been predicted and therefore research in the field of harnessing power from unlimited sources of energy such as sunlight is inevitable. Organic solar cell research in the last decade has attracted scientific and economic interest due to its easy and inexpensive fabrication and rapid improvement in power conversion efficiency. Future potential and increasing demand of green energy have also motivated government and private organizations, and researchers for harnessing abundant solar energy. ææA first breakthrough in organic solar cell research was realized by the discovery of improved dissociation of excitons at a donor/acceptor junction. Further improvements were made by switching from planar junction to homogeneous mixture of donor/acceptor bulk heterojunction. æOne of the most promising polymer semiconductors is pentacene which acts mainly as a donor molecule. Pentacene single crystal grown from the vapor phase and doped with iodine makes a Schottky type of solar cell where aluminum is cathode, showed a power conversion efficiency of 1.9%. When these doped pentacene crystals made bulk heterojunction with aluminum doped ZnO as transparent window, it showed a significant improvement in efficiency (4.5%). ææWe are exploring various fabrication possibilities and efficacy of solar cells using newly synthesized water soluble pentacene (WSP) which is non-toxic. æThe fabrication of a solar cell using WSP is straight forward due to it’s high solubility in water, ethanol etc. which is solution processable. æWe have designed, successfully fabricated and tested the photovoltaic cell.