Improvement of the power conversion efficiency of organic photovoltaic cells with a P3HT layer fabricated by using a sonication process and having a vertically modulated nanoscale morphology

► OPV cells utilizing a vertically modulated nanoscale morphology using sonication process. ► Vertically modulated morphology under 15 min sonication time process shows uniform morphology. ► The PCEs of the OPV cells with a P3HT layer sonicated for 15 min were significantly enhanced.