Nanocones may boost solar cell efficiency by 15%

The new cone structured material's positive attributes come about due to an ultrahigh refractive index—each cone is made of a type of material that acts inside as an insulator and outside as a conductor—under a microscope the material looks like a mass of bullets stood up on end atop a flat base.

It, like other topological insulators, exploits oscillations that occur as a result of changes in the concentration of electrons that come about when the material is struck by photons.

Each cone has a metal shell coating and a core that is based on a dielectric—a material made with them would be able to provide superior light absorption properties, making it ideal for not just solar cells, but a wide variety of photovoltaic applications ranging from optical fibers to waveguides and even lenses.

The researchers suggest that if such a material were to be used as part of a traditional thin-film solar cell, it could increase light absorption by up to 15% in both the visible and ultraviolet range.

In interviews with the press, the researchers pointed out that theirs is the first time that such a nanocone structure has been created and perhaps just as importantly, noted that creating them would not require any new fabrication techniques.

Also, they suggested that because of the better light absorption properties of the new material, "both the short circuit current and photoelectric conversion efficiency could be enhanced."

The researchers also note that unlike other nanostructures the oscillations generated by the nanocones are polarisation insensitive, which means they do not have to be directionally perpendicular to nanoslits making them more useful in a wider array of applications because they can be directly integrated into current hardware.

They add that they next plan to shift their efforts towards focusing on plasmonics that occur in other sorts of structures with different types of shapes.