Washington: Researchers at North Carolina State University have developed a new technique for improvement of the connections between stacked solar cells, which should improve the overall efficiency of solar energy devices and reduce the cost of solar energy production.
The discovery means solar cell manufacturers can create stacked solar cells that can handle high-intensity solar energies without losing voltage at the connecting junctions, potentially improving conversion efficiency.
Stacked solar cells consist of several solar cells that are stacked on top of one another. Stacked cells are currently the most efficient cells on the market, converting up to 45 percent of the solar energy they absorb into electricity.
But to be effective, solar cell designers need to ensure the connecting junctions between these stacked cells do not absorb any of the solar energy and do not siphon off the voltage the cells produce - effectively wasting that energy as heat.
This work is important because photovoltaic energy companies are interested in using lenses to concentrate solar energy, from one sun (no lens) to 4,000 suns or more. But if the solar energy is significantly intensified - to 700 suns or more - the connecting junctions used in existing stacked cells begin losing voltage. And the more intense the solar energy, the more voltage those junctions lose - thereby reducing the conversion efficiency.