Layered Mesoporous Nanostructures Improve Solar Cell Efficiency

University of Minnesota engineers have used layered mesoporous nanostructures to increase the efficiency of dye-sensitized solar cells (DSSC) by 26%.

The engineers have altered the design of an existing solar cell to make light to bounce through layers of tiny microscopic spheres. They engineered layers of micrometer and nanometer particles to increase the electricity-generating potential of these types of solar cells. DSSCs are manufactured from the photosensitive material - titanium dioxide, which is comparatively less costly than conventional silicon solar cells. Traditional solar cells are reaching their theoretical limit of efficiency. In the existing DSSCs, the light emitted from the infrared part of the light spectrum does not get absorbed easily. This disadvantage limits the efficiency of DSSCs to 10%.

The altered design enables more conversion of the electromagnetic spectrum to electricity, by increasing the path taken by light through the cell. Micrometer-scale spheres having nanometer pores are held between nanoscale particle layers in the solar cells. These spheres are manufactured from titanium dioxide. They make the photons to ricochet before allowing them to pass through the cell. The spheres simulate the tightly packed bumpers in a pinball machine. A charge is produced whenever an interaction between the photons and spheres occurs.