Sensitizers containing donor cascade and rhodanine-3-acetic acid moieties for dye-sensitized solar cells

Three organic dyes with D-π-D-π-A structure based on triarylamine, dimethylarylamine, and rhodanine-3-acetic acid moieties are designed and synthesized. Incorporating thiophene moieties into the system affords sensitizers with high molar extinction coefficients. These dyes were applied into nanocrystalline TiO₂ dye-sensitized solar cells through standard operations. For a typical device the maximal monochromatic incident photon-to-current conversion efficiency (IPCE) can reach 73%, with a short-circuit photocurrent density (J_sc) of 7.3 mA/cm², an open-circuit voltage (V_oc) of 636 mV, and a fill factor (ff) of 0.61, corresponding to an overall conversion efficiency (η) of 2.86%.