Solar cell technology has improved dramatically over the last decade, and one material giving researchers hope for the next generation of cells is perovskite. Perovskite is cheaper to manufacture in bulk than silicon, and can be printed or sprayed onto surfaces.
Perovskite isn’t perfect, of course, and it tends to break down because of exposure to ions released by metal oxide electrodes in the solar cell. A South Korean research team at Ulsan National Institute of Science and Technology (UNIST) has recently discovered the delicate perovskite can actually be protected using graphene.
The team’s breakthrough uses a graphene copper grid-embedded polyimide (GCEP), which is positioned between the cell’s metallic electrode and the layer of perovskite. This allows light photons and electrons to pass through the material and be converted to energy without the ions damaging the perovskite.
The team found their design, now cloaked in “graphene armor.” was almost as efficient as traditional solar cells. The graphene not only protected the fragile perovskite from damage, but aided in blocking out UV light as well, which can also damage solar cells. In a durability test, the team bent their solar cells more than 5,000 times, finding the cells retained 94% of their starting efficiency.
The team’s research was recently published in the journal Nano Letters.