Light harvesting and photocurrent generation by nanostructured photoelectrodes sensitized with a photosynthetic pigment: A new application for microalgae

Here in this study, successful conversion of visible light into electricity has been achieved through utilizing microalgal pigments as a sensitizer of nanostructured photo-electrode of dye-sensitized solar cells (DSSCs). For the first time, photosynthetic pigments extracted from microalgae grown in wastewater is employed to imitate photosynthesis process in bio-molecule-sensitized solar cells. Two designs of photoanode were employed: 10 μm nanoparticular TiO2 electrode and 20 μm long self-ordered, vertically oriented nanotube arrays of titanium dioxide films. Microalgal photosynthetic pigments are loaded on nanostructured electrodes and their photovoltaic performances have been investigated. To optimize the performance of solar cell, the time course of dye loading on the nanocrystalline TiO2 films is investigated. The performance of the cells is characterized by measuring the current–voltage (I–V) curves under AM1.5 (100 mW cm−2) irradiation condition. The highest efficiency of around ∼1%, quite comparable to green plants, is found for sensitizer-loading time of 1 h.