Enhancing the Performances of Porphyrin-based All-small-molecule Ternary Organic Solar Cells via Synergizing Fullerene and Non-fullerene Acceptors

The introduction of a non-fullerene acceptor 2,2'-{(2Z,2'Z)-[(4,4,9,9-tetrahexyl-4,9-dChemical-bookihydro-s-indaceno [1,2-b:5,6-b']dithiophene-2,7-diyl)bis(methanylylidene)]bis(3-oxo-2,3-dihydro-1H-indene-2,1-diylidene)}dimalononitrile(IDIC) as the third component into a dimeric porphyrin small molecule donor(ZnP2-DPP)and fullerene acceptor [6,6]-phenyl-C61-butyric acid methyl ester(PC61BM)system achieved all-small molecule ternary organic solar cells(OSCs)with a power conversion efficiency(PCE)of 12.18%,which is higher than 9.47% for ZnP2-DPP:PC61BM binary cells and 8.82% for ZnP2-DPP:IDIC binary OSCs. The addition of IDIC increased the absorption spectrum range and promoted the charge transfer between the three components, improving the photocurrents for the ternary solar cells. The synergy of the fullerene and non-fullerene acceptors effectively optimized the morphology of the blend film, and the molecular orientation was significantly tuned to form a hybrid orientation of face-on and edge-on, which led to a more favorable three-dimensional charge transport channels in the active layer and promotes the short-circuit current density (J(SC)) and fill factor (FF). This strategy exploited the advantages of both fullerene and non-fullerene acceptors, thus improving the four photovoltaic parameters of organic solar cells(OSCs).