Materials of the future - Graphene and perovskites

We continue the series “Materials of the future” with the promising combination of graphene and perovskites – a family of materials with the same crystal structure of the mineral calcium titanium oxide (CaTiO3), the first-discovered perovskite crystal.  

Perovskites are very efficient at absorbing photons of light, which can be converted into an electric current, thus creating an exciting alternative to silicon for solar cells. Since silicon solar cells are reaching their theoretical power conversion efficiency limit, perovskite solar cells have emerged as low-cost, light, flexible alternatives for photovoltaics.  

Although perovskite solar cells have demonstrated excellent performance, their efficiency declines quickly as the module size increases and in outdoor conditions. Air, humidity, and exposure to heat degrade the perovskite, reducing their advantages. Here graphene can help: it is hydrophobic and can protect perovskite solar cells from atmospheric degradation. It can also improve the overall electrical performance of the solar cells. 

The first solar farm in Crete 

Graphene Flagship’s Work Package for Energy Generation combined graphene and related materials to perovskite cells and reached record levels of performance and stability. The project resulted in the first graphene-perovskite solar farm. It was installed outdoors in Crete and demonstrated a peak power output of 250 W, comparable to commercial 60-cells silicon solar panels.  

The experiment was conducted by researchers of Graphene Flagship Partners Hellenic Mediterranean University (Greece), University of Rome Tor Vergata, BeDimensional S.p.A., Greatcell Solar Italia SRL, Italian Institute of Technology and the National Research Council (Italy). 

“We demonstrated that the use of layered materials, such as graphene and molybdenum disulfide, can improve the perovskite solar cells’ interface properties, not just on the lab scale, but also on large-area panels tested in real conditions, thus pushing the Technology Readiness Level to high values around 6-7,” said one of the leading members of the team, Aldo di Carlo from Graphene Flagship Partner University of Rome Tor Vergata, after their successful result. 

Bringing the product closer to the market 

Graphene Flagship Spearhead Project GRAPES is pushing solar cell technology a step ahead by reducing the levelised cost of energy to below €20 per MWh. Led by the company Enel Green Power (Italy), the GRAPES team aims to boost the performance and stability of perovskite cells to record levels, and fabricate cost-effective photovoltaic panels with stacked layers of graphene and layered materials, perovskite and silicon.  

References  

Pescetelli, Sara, et al. "Integration of two-dimensional materials-based perovskite solar panels into a stand-alone solar farm." Nature Energy (2022): 1-11. https://www.nature.com/articles/s41560-022-01035-4