High open-circuit voltage, high fill factor single-junction organic solar cells

We demonstrate a high open circuit voltage (Voc), high fill factor, single-junction organic photovoltaic (OPV) cell consisting of tetraphenyldibenzoperiflanthene (DBP) as the donor and pyrrolo[3,4-c]pyrrole- 1,4-dione, 3,6-bis(4-chlorophenyl)-2, 5-dihydro (DPP) as the acceptor in a vapor-deposited, fullerene free organic solar cell. Under one sun illumination, the DBP/DPP based planar heterojunction solar cell exhibits a Voc of 1.19 V with a fill factor of 0.67, leading to a final power conversion efficiency (PCE) of 2.2%. Our achieved Voc is the highest value reported thus far for a single-junction, high fill factor organic solar cell. A planar-mixed device architecture allows for high exciton generation while maintaining high exciton dissociation, leading to a PCE of 3.2%. The DBP and DPP interface creates a high interface energy gap (ΔEDA) and relatively low saturation current (JS) due to poor coupling across the donor-acceptor interface. These results support earlier theories that high Voc values are ...