Alignment of Cascaded Band-Gap via PCBM/ZnO Hybrid Interlayers for Efficient Perovskite Photovoltaic Cells

Abstract

In this study, we investigated methylammonium lead iodide (MAPbI(3))-perovskite solar cells (PSCs) with hybrid PC70BM/ZnO interlayers. The pristine device which had a PC70BM electron transport layer sandwiched between ITO/PEDOT:PSS/MAPbI(3) and TiO (x) /Al electrodes exhibited PCE of 12.72% with a V (OC) of 0.98 V, J (sc) of 18.41 mA/cm(2), and FF of 71%. The new device with hybrid PC70BM/ZnO interlayers exhibited higher PCE of 14.17% with a V (OC) of 0.98 V, J (SC) of 20.08 mA/cm(2), and FF of 72% due to the incorporation of ZnO nanoparticles in PC70BM electron transport layer (ETL) with high electron mobility and cascade band gap alignment. Here, we demonstrated that lower photoluminescence (PL) intensity of the device with hybrid interlayers could improve the JSC value of perovskite solar cells due to enhanced charge-generation efficiency. Contact resistance can be reduced by mixing ZnO nanoparticles with PC70BM electron transport layer without additional ZnO layer insertion.