Spinach and Silicon for Solar Power
When thinking about solar power, some may think it is this new technology that has been developed most extensively in recent times as a clean energy source. The truth is though that solar power has been in development for millions and even billions of years. Nature has been harnessing the power of sunlight for longer than man has existed, and researchers know that and are trying to take advantage of that.
Photosystem 1 (PS1) is a protein involved in photosynthesis that can convert sunlight to electrical energy with almost 100% efficiency; almost three times higher than the maximum efficiency possible with typical semiconductor solar cells. This protein also can continue function after it has been harvested from plants like spinach, but not always for long and is difficult to integrate with our technology. Researchers at Vanderbilt University overcame this though by doping the silicon substrate PS-1 was placed on. This is to prevent the protein from pulling electrons from the silicon to fill holes formed by the useable electric current.
The biohybrid solar cell the researchers created was able to generate 850 microamps per square centimeter and 0.3 V. That may not sound like much but represents nearly two and a half times better performance than previous biohybrid solar cells. With further work the researchers are confident they can improve the cells' performance even further and give new meaning to the phase 'green energy.'