Vegetable Power: Making Better Solar Cells With Spinach

Spinach: it’s more than just a delicious, nutritious vegetable. Researchers at Vanderbilt University have figured out how to make more powerful solar cells with a little help from Popeye’s favorite leafy green.

The researchers, who recently published their research in Advanced Materials, figured out how to mix the protein in spinach that turns light into electrochemical energy with silicon (used in many solar cells). The result: a "biohybrid" solar cell that generates more electrical current and voltage than all biohybrid solar cells created in the past (two and a half times more current than the highest levels reported previously).

The spinach-solar hybrid cell was created by extracting the photosynthetic protein from spinach, putting it into an aqueous solution, and pouring the mixture onto a silicon wafer. The wafer was placed in a vacuum chamber to get rid of any excess water, leaving only a protein film.

"This combination produces current levels almost 1,000 times higher than we were able to achieve by depositing the protein on various types of metals. It also produces a modest increase in voltage,” explained David Cliffel, one of the researchers behind the study, in a statement. "If we can continue on our current trajectory of increasing voltage and current levels, we could reach the range of mature solar conversion technologies in three years.” In other words, it may not be long before spinach-tinged solar cells hit the market.