Light Management through Organic Bulk Heterojunction and Carrier Interfacial Engineering for Perovskite Solar Cells with 23.5% Efficiency

Light management through organic bulk heterojunction (BHJ) has been widely reported to push up the performance of lead-based perovskite solar cells (PSCs) by extending the spectral response. However, the development of integrated perovskite/organic bulk heterojunction solar cells (IPSCs) encounters a bottleneck problem that the poor carrier extraction capability of perovskite and BHJ leads to the severe loss of open-voltage (V-oc) and fill factor (FF). Herein, the strategy of introducing black phosphorous quantum dots (BPQDs) and cuprous oxide (CuOx) into IPSCs is adopted, which not only successfully extends the single-component PSCs light response to 930 nm, but also significantly reduces the V-oc and FF loss of IPSCs. BPQDs with bipolar charge transport and high mobility characteristics improves the electron/hole transport behaviors of perovskite and BHJ films. CuOx with matching energy levels is introduced between BHJ and Spiro-OMeTAD as a buffer layer, which provides good driving force for the transportation of holes. The champion device achieves a power conversion efficiency of 23.52%. The IPSCs devices also display an excellent long-term and humidity stability. This work demonstrates an approach to solve the carrier extraction key issues that limits the performance of IPSCs, which achieves an instructive result in the development of PSCs light management.