Researchers at Vanderbilt University said they have found a way to build biohybrid solar cells using photosynthetic protein that converts light into electrochemical energy in spinach with silicon. Apparently the use of spinach increases current and voltage levels.
"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," said David Cliffel, associate professor of chemistry, at Vanderbilt. "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."
The use of biomaterials is attractive for scientists since they mar much more efficient than our artificial materials. While nature can convert sunlight into electrical energy with nearly 100-percent efficiency, the best man-made systems today are still below 50-percent. Of course, the wide availability of biomaterials is another factor that is promoting this kind of research. However, there is a long way to go until the technology will make it into production devices.
First, the researchers said that size matters -- they need a two-foot panel to generate "at least 100 milliamps at one volt." Their area size required to generate a certain power output may not be feasible enough when compared to traditional solar cells. The Vanderbilt researchers report that their PS1/silicon combination produces 850 microamps of current per square centimeter at 0.3 volts.
Also, the hybrid cells deteriorate rather fast. The scientists said that some early test cells deteriorated after only a few weeks. However, there have been scenarios in which the cells lasted for nine months. In nature, a PS1 cell in evergreens survives for years.