North Carolina State University researchers have come up with a new technique for improving the connections between stacked solar cells, which should improve the overall efficiency of solar energy devices and reduce the cost of solar energy production. In a breakthrough, scientists have created an array of solar cells that can withstand the blazing glare of 70,000 suns. Most solar panels are actually composed of a bunch of photovoltaic cells stacked on top of each other. The problem is that a lot of energy gets lost when the electrons hit the connective or junction cells that sit between each photovoltaic cell.
Benefits of New Solar Cell Design
Researchers have come up with a new technique for improving the connections between stacked solar cells, which should improve the overall efficiency of solar energy devices and reduce the cost of solar energy production. They found that by adding a thin film of gallium arsenide to the junction cells, they could practically eliminate voltage loss. 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 per cent of the solar energy they absorb into electricity and this new connection should improve upon that efficiency by reducing energy waste at connecting junctions. The new connection will allow the solar cells to handle up to 70,000 suns worth of energy. Now they have created a connecting junction that loses almost no voltage, even when the stacked solar cell is exposed to 70,000 suns of solar energy.
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. However, 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.
The solar cell manufacturers can now create stacked cells that can handle these high intensity solar energies without losing voltage at the connecting junctions, thus potentially improving conversion efficiency. This should reduce overall costs for the energy industry because, rather than creating large, expensive solar cells, you can use much smaller cells that produce just as much electricity by absorbing intensified solar energy from concentrating lenses. And concentrating lenses are relatively inexpensive.