Recent Progress in Nanoscale Morphology Control for High Performance Polymer Solar Cells

The nanoscale morphology of the electronic donor and acceptor materials in photoactive layers significantly influences both the exciton split and charge carrier delocalization and extraction processes in prevalent bulk-heterojunction (BHJ) based polymer solar cells (PSCs). An optimized morphology, including interpenetrating networks of donor and acceptor materials, nanoscale phase separation, and a vertical percolation path with a high concentration of electron donors at the anode and acceptors at the cathode, is a prerequisite for achieving highly efficient PSCs. Moreover, the stability of the material morphology is also gaining increasing attention because it is an important factor that can also affect the durability of the photovoltaic devices. This review summarizes the recent progress in nanoscale morphology control of BHJ PSCs towards further enhancement in device performance and life time.