Solar Cells Made More Cost- and Energy-Efficient
December 31, 2015
Excerpted from Haaretz — A joint team of physicists co-headed by Dr. Avi Niv from the Alexandre Yersin Department of Solar Energy and Environmental Physics of BGU’s Jacob Blaustein Institutes for Desert Research has discovered a new light trapping technique that boosts the efficiency of electricity-generating ultra-thin solar cells by more than 30 percent, all without using costly new materials.
In general, the way to make solar cells more cost-effective has been to make them thinner without impairing their ability to produce power. In practice, that means reducing the thickness of the cells’ light-absorbing layers (which turn light into electricity) without compromising their efficacy.
The problem is that the thinner the layer, the more difficult it becomes to effectively trap light, due to the fact that at small lengths, light behaves more erratically.
The team’s invention, detailed in the Journal of Materials Chemistry, is a new method that combines ray-based trapping with wave-optics absorption.
They achieved this by structurally separating the trapping and absorption sites within the cell. The result was enhancements of more than 30 percent in the cell’s power production, and the team predicts they can reach increases of 40 percent and beyond.
“Finding a way to harness ray optics for boosting the absorption of ultra-thin cells, as was done here, could have a large impact on the future of solar cells,” says Dr. Niv.
Prof. Avner Rothschild of the Technion – Israel Institute of Technology is the research team’s co-leader.