Using metamaterials to design new solar cells

Investigating the need for sustainable energy, Dr Shanks and her colleagues focus specifically on solar panels as one key solution. The ideal solar panel would be highly efficient, lightweight, cost, and carbon effective. They also need to be able to be applied in any orientation or any environment. The key applications for this technology are in areas like building integration, smart structures, and electric vehicles, all of which present a need for a higher power density. Lots of sectors are trying to reduce their carbon footprint and solar photovoltaics are one of the few renewable energy technologies that can be utilised on sub mm areas up to km sized fields.

Currently solar panel technology is either efficient but expensive, or lightweight and less powerful. The goal is to combine high efficiency with lightweight compact panels and introduce multifunctionality.

Dr Shanks looks at solar concentrators which are a combination of optics with solar cells.  Within this, there is a focus on nano-structured optics, or metamaterial optics. One of the areas she is interested in is bio mimicry where the optical properties of butterfly wings and moth eyes can be explored with regards to the management of light and hence solar panel performance.

By using optical metamaterials, we have greater control of the shape of the solar cell without a loss in effectiveness allowing us to reduce the size and weight. This is vital for extending the usage of solar panels in new scenarios such as on vehicles etc. The reduced size also provides other distinct advantages by reducing the amount of material needed in manufacture to reduce both the financial and environmental cost.

 

Another advantage is that metamaterials can lead to improved reliability by increasing the acceptance angle using beam-steering optics or by implementing passive tracking mechanisms to adjust the orientation relative to the Sun without additional power input.