For years the efficiency of polymer-based solar cells scraped along at a feeble 3% to 5%. But things have improved markedly over the past 2 years. In early April, Mitsubishi Chemical reportedly set a new efficiency record, producing organic solar cells with a 9.2% conversion efficiency. Meanwhile, three other companies—Konarka Technologies, Solarmer Energy Inc., and Heliatek—are now reporting cells with efficiencies greater than 8%. Many researchers in the field are confident that the figure could soon top 10% and possibly reach 15%.