Grätzel cell - Dye-sensitized solar cell (DSC)

Anthocyanins can be used in Grätzel cells to produce electric power out of sunlight. Grätzel cells are also known as dye-sensitized solar cells (DSCs). Dye-sensitized solar cells (DSCs) have several advantages over silicon based solar cells.

- very simple composition

- low costs

- can be operated with low sun radiation

- two-sided operation possible (bifacial)

- doesn't contain rare earth elements

- dyes are biodegradable and nontoxic

A simple dye-sensitized solar cell contains...

- a dye like pelargonidin

- an electrolyte/redox system like Lugol's iodine

- one conductive glass slide which is coated with TiO2 on one side

- one conductive glass slide which is coated with graphite on one side

These solar cells exploit the ability of certain dyes, like anthocyanins, to transfer electrons on titanium dioxide, when they are in an excited state.

This excited state is induced by sun radiation. After electron transfer, the anthocyanine molecules are positively charged. By receiving an electron from a redox system, the molecules returns into a non-charged state. The redox system, which consists of an iodide electrolyte solution, is reduced and regenerated by a graphite electrode.