New, Cheap, Environmentally-Friendly Solar Cell Created in Energy Breakthrough

There's a new, environmentally friendly solar cell that uses tin instead of lead perovskite in order to harvest light. The low-cost solar cell could potentially be a breakthrough for solar energy.

The solar cell in question actually uses a structure called a perovskite; yet instead of lead, it employs tin for its light-absorbing material. Most other cells use lead, which achieves about a 15 percent efficiency; the new tin cell should be able to match and possibly even surpass that.

"Our tin-based perovskite layer acts as an efficient sunlight absorber that is sandwiched between two electric charge transport layers for conducting electricity to the outside world," said Robert Chang, one of the researchers, in a news release.

Currently, the solid-state tin solar cell only has an efficient of just below 6 percent. Yet this is a good starting point; it can absorb most of the visible light spectrum, and the perovskite salt can be dissolved and will reform upon solvent removal without heating. The cell itself is composed of a sandwich of five layers, with each layer contributing to something important; there's electrically conducting glass, titanium dioxide, tin perovskite, a hole transport layer, and a thin layer of gold.

"Other scientists will see what we have done and improve on our methods," said Mecouri Kanatzidis, one of the researchers, in a news release. "There is no reason this new material can't reach an efficiency better than 15 percent, which is what the lead perovskite solar cell offers. Tin and lead are in the same group in the periodic table, so we expect similar results."

The new solar cell could potentially help expand the use of solar energy. Not only that, but it provides and environmentally friendly substitute for lead. That said, more research will have to be done in order to improve the cell's efficiency.

The findings are published in the journal Nature Photonics.