Abstract
Photovoltaic cells of the type (Al/monolayers of photosynthetic pigments/Ag) have been prepared by sandwiching pigment monolayers in between semitransparent Al and Ag electrodes. The use of monolayers is to simulate the in vivo orientation of pigments. The power conversion efficiency of Chl a cells, measured at 680 nm (red absorption band of Chl a) is ~ 0.03%. The addition of quinone (α-TCPQ) or carotenoid canthaxanthine does not seem to increase the efficiency of the Chl a cells. The capacitance measurements at low frequency, i.e., 0.10 Hz in dark and under illumination indicate the presence of large number of trapped charge carriers which are mobilized by light. The action spectra suggest that the photoactive region is at the Al/pigment junction.