Thermally Stable, Efficient Polymer Solar Cells with Nanoscale Control of the Interpenetrating Network Morphology


  • This research was supported by Konarka Technologies (Lowell, MA) and by the Air Force Office of Scientific Research, AFOSR, under FA9550–05–0139 and by AFOSR through the MURI Center (“Polymer Smart Skins”, F49620–01–10364), Charles Lee, Program Officer.


By applying the specific fabrication conditions summarized in the Experimental section and post-production annealing at 150 °C, polymer solar cells with power-conversion efficiency approaching 5 % are demonstrated. These devices exhibit remarkable thermal stability. We attribute the improved performance to changes in the bulk heterojunction material induced by thermal annealing. The improved nanoscale morphology, the increased crystallinity of the semiconducting polymer, and the improved contact to the electron-collecting electrode facilitate charge generation, charge transport to, and charge collection at the electrodes, thereby enhancing the device efficiency by lowering the series resistance of the polymer solar cells.