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 eight years ago by Shuguang Zhang, an associate director and a principal research scientist at Center for Biomedical Engineering in MIT. The work shows a promising step towards 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 that could generate current upon exposure to sunlight. However, this system had certain disadvantages. 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 laboratory to replicate it, thus helping researchers across the world to make further enhancements.
This improved efficiency was achieved by Mershin who used pine trees. He created a microscopic forest of zinc oxide (ZnO) nanowires and a titanium dioxide (TiO2) nanostructure, which was coated with a 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, even grass clippings, can be used as a raw material. Mershin and his colleagues have recommended a way to concentrate the PS-I molecules by utilizing cheaper membranes for filtration. This research work paves the 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 has been partly funded by Intel.