STFTYT: A simple and broadly absorbing small molecule for efficient organic solar cells with a very low energy loss

A simple and easily accessible A-π-D-π-A small molecule STFTYT with alkylthiophene as the π-conjugated bridge was designed and synthesized for organic solar cell (OSC) applications. The target material exhibits an incredibly broad absorption, a small bandgap and low-lying HOMO energy level. An extremely high Voc of 0.97 V was achieved for OSCs based on STFTYT along with an excellent PCE of 6.19% and a very low energy loss of 0.56 eV.191