Chlorophyll complexes in light-harvesting complexes absorb solar energy and transfer it to the reaction center (RC) at the beginning of the photosynthetic process. The RC converts the absorbed energy into electrochemical energy. We are interested in understanding the rapid and efficient energy transfer between chlorophyll complexes, and have been aiming to construct an artificial photoenergy conversion material based on a natural solar energy conversion system. The chlorophyll complexes, isolated from native bacterium or plant and their synthetic model complexes were successfully assembled onto various electrodes modified with various terminated. Efficient energy transfer and photocurrent responses of the complexes were observed upon illumination.
An enhanced photocurrent was also observed in the case of LH model polypeptides assembled with chlorophyll derivatives onto an electrode. In this case the photocurrent response depended on the structure of the model complex. Various combinations of these complexes are being tested for their usefulness in constructing artificial solar energy conversion materials.