Quadrupolar D-A-D diketopyrrolopyrrole-based small molecule for ternary blend polymer solar cells

A quadrupole diketopyrrolopyrrole (DPP)-based small molecule (DPP4T-Cz) with high absorption coefficient was designed and incorporated into the host binary blend of P3HT:PCBM to improve the light harvesting in the near-IR range. Interestingly, photocurrent ascribed to P3HT was also enhanced through energy transfer from P3HT to DPP4T-Cz. As a result, the PCE was increased by more than 30% compared to those of the binary blend control cells.260