MIT Researcher Develops Solar Cells from Plant Material

Andreas Mershin, a researcher at the MIT’s Center for Bits and Atoms, has developed a photovoltaic cell from plant materials. This work is an expansion of a research project, which was started by Shuguang Zhang, an associate director at Center for Biomedical Engineering in MIT, eight years ago. The work shows a promising step towards the integration of biomolecules to build solar cells.

Zhang sourced tiny molecules in plant cells that are responsible for photosynthesis. The photosystem-I (PS-I), which was derived from plants, was stabilized chemically. Then a layer was created over a glass substrate. The resulting solar cell could produce current when exposed to sunlight, but it had a few shortcomings. The stabilizing and assembling processes required modern lab equipment and expensive chemicals. In addition, the cell had very less efficiency.

Now, the new process has significantly increased the solar cell efficiency, which is 10,000 times higher than the earlier system. The simplified process allows any laboratories to replicate it, thus helping researchers across the world to make further enhancements.

The high efficiency advance has been made by Mershin by using pine trees. He created a microscopic forest of zinc oxide (ZnO) nanowires and a titanium dioxide (TiO₂) nanostructure, which was coated with light-absorbing material sourced from bacteria. The development resembled an electric nanoforest. ZnO and TiO₂ are good UV absorbing materials.

Mershin informed that anything green and even grass clippings can be used as raw material. His tram has developed a way to concentrate the PS-I molecules by using cheaper membranes for filtration.

This research work paves way for the development of organic photovoltaic solar cells that can employ naturally produced cores. The project includes scientists from the University of Tennessee and it has been partly funded by Intel.