Disclosed is a technique for fabricating a bio-photovoltaic cell which includes coupling graminoids extracted from natural grasses to a semiconductor electron acceptor, on which plasmonic silver nanoparticles are aligned, by using an organic ligand material. More particularly, disclosed is a technique for fabricating a new renewable energy generation device useable for fabrication of high efficiency bio-photovoltaic cells by improving a photo-electron generation rate of graminoids through a surface plasmon effect of silver nanoparticles and increasing an effective photo-electron amount transferred to the electron acceptor due to optimized bonding between a photo sensitizer and an electron acceptor.