A study of reverse bias in a dye sensitised photoelectrochemical device

A dye-sensitized nanocrystalline solar subjected to reverse bias of 800 mV showed no measurable loss in performance. However, at 2000 mV, a dramatic and irreversible reduction in the cells performance is observed. Raman spectroscopy experiments suggested that no desorption of the photosensitising dye occurred. Spectroelectrochemical experiments revealed that an irreversible loss of intensity in the metal to ligand charge transfer band at 540 nm occurred. In practical terms, these results indicate that cells which are incorrectly connected to an array of cells or a system failure where potentials greater than 1500 mV are present, may be irreversibly damaged.