Increased Efficiency of Organic Solar Cells by Seeded Control of the Molecular Morphology in the Active Layer

The performance of non-fullerene, polymer bulk heterojunction (BHJ) organic photovoltaic devices has a significant correlation with the molecular morphology donor and acceptor. authors show that small molecules coordinated to metal oxide, an electron transport seed layer (ETSL), can profoundly modify donor:acceptor inverted (OPV) devices. Using grazing incidence wide angle X-ray scattering (GIWAXS), PTB7-Th:IEICO-4F BHJ active higher degree face-on alignment on ETSL-1 (biphenyl-4,4?-dicarboxylic acid, ZnO), whilst for naphthalene-2,6-dicarboxylic acid ZnO (ETSL-2), it is reduced. Devices prepared had 19.91% increase in average power conversion efficiency (PCE), 1.56% fill factor (FF), 16.66 ± 0.2% enhancement short circuit current density. observed improvements are believed be due modifications oxide-BHJ interfacial region ETSL-1, namely elimination nano-ridges defect centers, along enhanced wettability. These factors correlated device performances, leading conclusion modulation blends by broad impact improving OPV cell efficiencies.