Performance of Solution Processed Organic Photovoltaic Cells Using A-D-A Type Small Molecular Donors

Abstract

The performance of solution processed bulk heterojunction (BHJ) organic photovoltaic cells (OPVs) has been remarkably improved during the past two decades. Most of BHJ OPVs were produced using polymeric donor materials, since the polymeric donor materials can provide the advantage of easily tailoring the morphology of photoactive films of BHJ OPVs. However, the difficulty in synthetic reproducibility and purification of polymeric donor was main drawback to overcome. In this study, we designed and synthesized A-D-A type small molecular donor materials (BDT(IId)(2)) containing alternatively linked benzodithiophene (BDT) and Isoindigo units. Also, we investigated the effects of the substituent and alkyl chains of on the efficiency of OPVs. Finally, 2.46% of power conversion efficiency (PCE) can be obtained using a mixture of synthesized small molecular donor and PCBM as an active layer with a Voc of 0.99V, a Jsc of 6.82mA/cm(2), and a fill factor of 0.36.