Photocurrent activity of light-harvesting complex II isolated from spinach and its pigments in dye-sensitized TiO2 solar cell

Light-harvesting complex II (LHCII) was used as sensitizer in biosolar cell. To improve the cell performance, we studied the adsorbing conditions and compared the photocurrent activity of LHCII and its pigments. The maximum adsorbances were achieved at the concentration over 80 μg chl/ml with 96 h incubation for LHCII and at the concentration over 120 μg chl/ml with 24 h incubation for pigments. The initial performance of pigment-sensitized solar cell was superior to that of LHCII-sensitized solar cell. With the increase of adsorbance, both the short-circuit current and efficiency increased for LHCII-sensitized solar cell and pigment-sensitized solar cell. The best short-circuit current, open-circuit voltage, fill factor and efficiency were 2.26 mA/cm2, 0.53 V, 0.69 and 0.79% for pigment-sensitized solar cells and 0.80 mA/cm2, 0.59 V, 0.58 and 0.27% for LHCII-sensitized solar cells, respectively. The adsorption models of LHCII and pigments on TiO2 are proposed, and the strategies for further study are briefly discussed.