VATIS UPDATE Article

Researchers at University of Michigan (U-M), the United States, have developed a new semiconductor alloy that can capture the near-infrared light located on the leading edge of the visible light spectrum. Easier to manufacture and at least 25 percent less costly than previous formulations, it’s believed to be the world’s most cost-effective material that can capture near-infrared light – and is compatible with the gallium arsenide semiconductors often used in concentrator photovoltaics.

This could be a major step forward for a new generation of solar cells called “concentrator photovoltaics”. Concentrator photovoltaics gather and focus sunlight onto small, high-efficiency solar cells made of gallium arsenide or germanium semiconductors. They’re on track to achieve efficiency rates of over 50 percent, while conventional flat-panel silicon solar cells top out in the mid-20s. Researchers devised a novel approach for keeping tabs on the many variables in the process.

They combined on-the-ground measurement methods including X-ray diffraction done at U-M and ion beam analysis done at Los Alamos National Laboratory with custom-built computer modeling. Using this method, they discovered that a slightly different type of arsenic molecule would pair more effectively with the bismuth. They were able to tweak the amount of nitrogen and bismuth in the mix, enabling them to eliminate an additional manufacturing step that previous formulas required.