Improved performance of dye-sensitized solar cells by trace amount Cr-doped TiO2 photoelectrodes

► The trace amounts of Cr-doped TiO2 have been used for the dye-sensitized solar cells (DSSCs). ► The short-circuit photocurrent density and electron lifetime have increase-decrease trace. ► The overall energy conversion efficiency has increased to 6.35% with 50 ppm Cr-doped TiO2. ► The electron transport property has enhanced significantly with Cr-doped TiO2.