Highly Efficient Porphyrin-Based OPV/Perovskite Hybrid Solar Cells with Extended Photoresponse and High Fill Factor

Abstract

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 (J_SC) 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 J_SC, but also possess suitable energy levels and high mobility to afford high V_OC 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 V_oc, J_SC, 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.

A highly efficient organic photovoltaics/perovskite hybrid solar cell is demonstrated by blending a new conjugated porphyrin-based small molecule with [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) to function as an efficient bulk-heterojunction layer. The extended photoresponse, matched energy levels, and high hole mobility derived from the optimized bulk-heterojunction morphology contribute to the record-high efficiency of 19.02% in these hybrid devices.

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