Researchers from Singapore's A*STAR institute discovered that graphene outperforms ITO as solar panels transparent electrodes. The researchers say that stacking four graphene sheets is the best method - as more graphene sheets decrease the resistance but blocks more light.
A single graphene sheets blocks less than 3% of light which means more light can reach the solar panel. Graphene's efficiency as a solar panel electrode depends on the type of light absorbed by the panel. For solar panels that absorb near-infrared light graphene is only slightly less effective than ITO, while graphene would be ideally suited to photovoltaic cells with a very broad absorption range, such as a recently developed organic solar cell that can harvest light from 350 to 850 nanometers.
The researchers say that they expect the sheet resistance of graphene to become an order of magnitude lower than the current state of the art when new and refined production technologies emerge. This will allow using only two sheet of graphene which will outperform ITO on both conductivity and transparency.