Researchers from Sharif University in Iran have received a U.S. patent for their innovative restructuring of solar cells. Iran’s Nanotechnology Initiative Council reports that “single-sided dye-sensitized solar cells having a vertical patterned structure” eliminates the need to use conductive glass when constructing solar cells.

Conductive glass in solar cells uses ionic to electronic conductivity by mixing metals like gold into glass. Indium tin oxide, another conductive material added to glass, is quite expensive, and has encouraged scientists to find alternative materials.

By eliminating the need for conductive glass with the construction of dye-sensitized cells, the team from Sharif may significantly drive down the cost of producing solar panels.

“Dye-sensitized solar cells are a type of nanostructured solar cells whose mechanism is based on light absorption by the pigment molecules plus electron and hole injection to a semiconductor and an electrolyte,” explained Nima Taqavinia of Sharif’s Nanoparticles and Nanocoatings Lab in the Department of Physics. “This highly resembles the photosynthesis occurring in plants.”

Taqavinia says researchers’ main objective is to make sure that the new solar cell technology makes its way to the commercial sphere. “For fabrication of a small panel of solar cells, a large number of layering and heat treatment steps are required. Once regarded from the mass production viewpoint, each of such apparently simple steps demands a great deal of design and operation.”

The idea of illuminated organic dyes that conduct electricity has been discussed since the 1960s and 1970s, when scientists from UC Berkeley tried to conduct electricity with chlorophyll extracted from spinach.

On a dye-sensitized solar cell, sunlight passes through a transparent electrode into a layer of dye. The light excites electrons in the dye that then flow into a layer of titanium dioxide.

Once the electrons reach the titanium dioxide, they are transported back to the electrode, where they are collected to power a load. They flow through an external circuit and are put back into the cell through a metal electrode on the back. Electrons flow through an electrolyte solution back to the dye.

Dye-sensitized solar cells have not been as efficient in the past as solar cells using conductive glass. The Iranian team did not comment specifically on this issue.

Taqavinia, however, expressed a great deal of confidence in the new solar cells.

“The production rate, processing cost, cost of the raw materials, and all other parameters impacting the final cost shall be so that the new product beats its rivals,” Taqavinia concluded. “Also, the durability and excellence of performance are two of other key factors. As a result, a combination of parameters together with technical novelty can guarantee a promising commercialization.”