Finely tuned: A stable dye-sensitized solar cell that contains a molecularly engineered org. dye was prepd. The efficiency of the cell remains at 90% after 1000 h of light soaking at 60°. The remarkable stability of the cell is also reflected in the open-circuit voltage value (Voc), short-circuit photocurrent-d. value (Jsc), and the fill factor, which also show barely no decline.