Ternary blend of conjugated polymers for broadening the absorption bandwidth of polymer solar cells

Abstract

Ternary blend all-polymer solar cells are developed to broaden the absorption bandwidth of the photoactive layer. A wide-bandgap polymer with absorption in the visible region is introduced as a third polymer into a low-bandgap donor/acceptor binary polymer blend showing absorption in the near-infrared (NIR) region. In the ternary blend solar cell, the external quantum efficiency (EQE) is improved in the visible wavelength region, while retaining the excellent EQE of the host binary blend in the NIR wavelength region. These results demonstrate that the use of ternary blends of conjugated polymers containing a wide-bandgap polymer as a visible sensitizer is an effective approach for improving the efficiency of all-polymer solar cells.