Thin-film Solar Cells Freed from Toxic Processing

Researchers found that magnesium chloride, a salt used to make tofu and de-ice winter roads, can be used to make thin-film solar cells effective, cheap, and nontoxic.

The new, poison-free process could help thin-film solar cells challenge the dominance of silicon photovoltaics, which make up roughly 90 percent of the world’s solar market but have some serious drawbacks.  Silicon does not absorb sunlight particularly well, so modules require layers of very high purity crystals, each more than 150 micrometers thick.  The cost of these silicon slabs is hampering efforts to further reduce the price of solar power.

Thin-film solar cells offer a solution.  By using semiconductors that harvest the sun’s rays much more efficiently, they can get similar results with sheets of lower purity material that are only 2 micrometers thick.  The difference: a significant reduction in manufacturing costs.

Thin-film Solar Cells Freed from Toxic Processing