Highly Efficient Porphyrin Based OPV/Perovskite Hybrid Solar Cells with Extended Photoresponse and High Fill Factor.
Employing a layer of bulk heterojunction (BHJ) organic semiconductors on top of perovskite to further extend its photoresponse is considered as a simple and promising way to enhance the efficiency of perovskite based solar cells, instead of using tandem devices or near infrared (NIR) absorbing Sn containing perovskites. However, the progress made from this approach is quite limited because very few such hybrid solar cells can simultaneously show high short circuit current (JSC and fill factor (FF) To find an appropriate NIR absorbing BHJ is essential for highly efficient, organic, photovoltaics (OPV)/perovskite hybrid solar cells. The materials involved in the BHJ layer not only need to have broad photoresponse to increase JSC but also possess suitable energy levels and high mobility to afford high VOC and FF. In this work, a new porphyrin is synthesized and blended with [6,6] phenyl C61 butyric acid methyl ester (PCBM) to function as an efficient BHJ for OPV/perovskite hybrid solar cells. The extended photoresponse, well matched energy levels, and high hole mobility from optimized BHJ morphology afford a very high power conversion efficiency (PCE) (19.02% with high Voc JSC and FF achieved simultaneously. This is the highest value reported so far for such hybrid devices, which demonstrates the feasibility of further improving the efficiency of perovskite devices.
Advanced materials