Braggone captures more light for solar cells

Braggone captures more light for solar cells

by By Ann Steffora Mutschler, Senior Editor - Electronic News
Thursday 11 October 2007

Braggone, the Finland-based optoelectronic materials supplier, has unveiled a materials-based approach to increasing the efficiency of solar cells, also aimed at allowing manufacturing facilities to cost-effectively increase their capacity.

Braggone says that incorporating its materials into the manufacturing process can allow the costs of manufacturing solar cells to be dramatically reduced.

The company outlines that the basic building block of solar cells - silicon - is very shiny and reflects about 30 percent of sunlight back into the sky. Solar companies trap this light by putting down very thin anti-reflective coatings to reduce the reflected light, and to help trap as much photo energy and convert it into as much electricity as possible, the silicon must be either of very high purity or have very few defects, Braggone explained.

Over the years, the company said, the conversion process has been accomplished by introducing hydrogen into manufacturing, and until now, the anti-reflective and hydrogenation for advanced cells has been done with a chemical vapour deposition (CVD) process.

Dr. Yrjö Ojasaar, CEO of Braggone noted that the optical and electrical layers were previously integrated into components through expensive and high maintenance CVD tools but that the company can now introduce the same anti-reflective and hydrogenation techniques with a simple and cost efficient spray coat, bake and repeat process.

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The company says it is essentially minimizing the optical loss in solar cells and modules and capturing as much light as possible in the cells by taming the physics.

Braggone says with the new materials, it is possible to reduce optical loss in the cell or module, as well as improve the efficiency of electrical conversion within the cell, which has the real benefit of driving down production cost per megawatt output.

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