13 Dec Scientists Successfully “Mimic” Fullerenes to Advance Organic Solar Cell Technology
Many researchers and manufacturers have pegged organic solar cells as the future for the solar industry because the manufacturing process entails the use of flexible and cheap polymers. Scientists from the University of Warwick Department of Chemistry have published a new study in the journal Advanced Materials. The paper covers the details of their discovery that fullerene, one of the main components required to fabricate organic solar cells, has another property—electrons accepting states.
These finding help researchers to create a new category of fullerenes called “fullerene mimics.” Fullerene mimics have has similar characteristics to fullerene.
Attributes of Fullerenes
Fullerene refers to a third form of carbon molecule that falls between the other two carbon molecules– graphite and diamond. Named after the geodesic dome designer Richard Buckminster Fuller, the molecule looks like spherical fullerenes. The carbon atoms of spherical fullerenes can be arranged in three forms: cylindrical, ellipsoid, or spherical. The cylindrical forms are called “nanotubes” or “Buckytubes.” The spherical fullerenes are called “Buckyballs
The typical fullerene molecule consists of 60-70 carbon atoms.
The key benefit of Fullerenes to industrial manufacturing has to do with the tensile strength of nanotubes, which have strength 20-times the strength of steel alloys. Fullerenes also have 50% of the density of aluminum and superconductive properties. The fullerene mimics have enormous potential for materials science, electronic wires, and computer memory applications.
Unlike the volume of graphite and diamond nature produces, fullerenes are scarce.
New Material “Mimics” Fullerene
Since the discovery of fullerenes decades ago, solar cell manufacturers have focused R&D resources into finding a suitable option to fullerenes. The material has shortcomings as electronic acceptors, a restricted ability to absorb light, and a high cost.
The University of Warwick researchers developed a set of procedures, which artificially produce fullerenes. The fabrication process includes the vaporization of graphite rods and a catalytic chemical vapor deposition process utilizing ethanol vapor.
The lead scientist in the project, Professor Alessandro Troisi, says the fullerenes ability to accept electrons in a multiple excited states speed up the electron capture process. In addition, the excited state makes the charge process more efficient.
The researchers must design the excited state in the materials, according to Troisi. This may explain why prior attempts by photovoltaic researchers to find a viable replacement for fullerenes have not been successful. “By pinpointing this particular way in which fullerene behaves, we believe we have found a key which may unlock the door to new replacements for this material,” said Troisi.
This breakthrough could also lead to the development of blends for manufacturing organic solar cells. The researchers have filed a patent for the process. They are currently seeking partners to help them bring the product to market.