The Karlsruhe Institute of Technology (KIT) discovered a cheat for greater organic solar cell efficiency based on the epidermal cells of rose petals.
Rose petals have certain properties that when artificially reproduced on a larger scale, such as a solar cell, yields more power.
Researchers from the Light Technology Institute (LTI), the Institute of Microstructure Technology (IMT), the Institute of Applied Physics (APH), and the Zoological Institute (ZOO) of KIT and the ZSW, checked out various plant species.
An electron microscope displayed an epidermis composed of a “disorganized arrangement” of crowded microstructures and nanostructures in rose petals. The same principles that make rose petals optimal for light-harvesting can be applied to solar cells.
Solar cells make electricity from sunlight after the release of electrons that travel through an electric circuit.
The scientists applied the rose petal epidermal cells to a polymerized mold that was then pressed into optical glue. The glue was left to dry under UV light. The resulting replica was then incorporated into a solar cell.
The new technique resulted in an increase of 12 percent of power conversion efficiency. The reasons behind the gain in solar cell power are currently under investigation. The researchers speculate that the omnidirectional antireflection properties seen in the epidermis leads to less surface reflection.
The artificial epidermis has a surface reflection value below 5 percent, or a significant value that remains the same even with light incidence angles that stretch to 80 degrees. It is also thought that the microlense effect might be a key player in the solar cell’s efficiency. When the optical path in the solar cell is increased, photons are more likely to be absorbed by the material.
In the future, the researchers hope to better understand what makes disorganization in photonic structures important to the absorbance of light.
