Role of nanoscale morphology on the nano and macro-scale performance of polythiophene based polymer solar cells

Maximization of the short circuit current, J$_{SC}$, the open circuit voltage, V$_{OC}$, and the fill factor (FF) to achieve highest power conversion efficiencies (PCEs) in donor/acceptor, polymer/polymer, solar cells is dependent on optimization of variables associated with the active material's chemical and morphological structure. Control of the nanoscale structure of polythiophene (P3HT)/phenyl-C61-butyric acid methyl ether (PC$_{61}$BM) active materials was achieved through use of a novel low temperature processing strategy. With the use of energy filtered transmission electron microscopy (EF-TEM), electron and X-ray diffraction, together phase contrast, deflection and photocurrent measurements at the nanoscale, we were able to tailor nanoscale morphologies to achieve increases in the J$_{SC}$ by a factor of 1.2 and the PCE by 30{\%}, beyond that using conventional heat treatments for processing.