Light-harvesting complexes absorb solar energy and transfer it to the reaction center at the beginning of the photosynthetic process. The RC converts the absorbed energy into electrochemical energy. These reactions take place within a ‘core complex’ consisting of a RC located inside the LH complex. We are interested in understanding the rapid and efficient energy transfer between LH and RC, and have been aiming to construct an artificial solar energy device based on a natural solar energy conversion system such as the core complex. The core complex, isolated from the photosynthetic bacterium or plant was successfully assembled onto various electrodes modified with various terminated. Efficient energy transfer and photocurrent responses of the complexes were observed upon illumination. Further, the photocurrent generated from the core complexes on the electrode depended on the wavelength of the exciting light. An action spectrum of this photocurrent showed a maximum at the wavelength corresponding to the absorption band of the LH core complexes.