Abstract: The photovoltaic characters of the sandwich cell, SnO_2/chla/PVA/SnO_2, were reported. The mechanism of photovoltaic effect of the cell was discussed, so that the dark rectifying effect was explained and the charge seperation under irradiation was occured at the junction of chla/SnO_2. We measured the output parameters of the cell, and improved the cell efficiency by adding hydro-quinone and so on into it. As a result, the short current and power conversion yield were increased over one digital order.

Key words: Chlorophyll-a, Sandwich cell, Photovoltaic effect, Optical transparent electrode