When people talk about the efficiency of solar cells, the conversation is usually about the efficiency of converting sunlight into electricity. But there are other opportunities for efficiency, from the manufacturing of cells to the ease of installing them.
Researchers in Germany are working on the manufacturing issue by focusing on the process that produces highly pure crystalline materials such as silicon.
In the method in use today, a narrow region of the silicon is melted using electricity, a process known as zone melting. The power supply used for this rely on tube-based amplifiers, which have an efficiency of 65 percent.
Researchers at Karlsruhe Institute of Technology found that by switching the power source from tube-based amplifiers to silicon carbide semiconductors, the efficiency could be brought up to “well over” 80 percent.
The project was funded by €800,000 from the German Federal Ministry of Research with support from industrial partners TRUMPF Hüttinger and IXYS Semiconductor.
“Power supply of energy-intensive industrial applications, such as a floating zone process, requires switching at high frequencies,” Rainer Kling, project manager at LTI, said in a statement. “Silicon carbide has not yet been tested at these high frequencies. Here, we are entering new territory.”
Silicon carbide devices has been gaining traction over silicon, because they can withstand higher voltages and temperatures due to their wider bandgap.
Circuits with higher efficiency that can withstand tough environments have applications far beyond making silicon for solar cells. Researchers are looking at silicon carbide for chips in jet engines and spacecraft, trains, cars, and elsewhere.
Germany is not alone in putting its energy toward wide-bandgap semiconductors. Last year, the United States opened up a new manufacturing innovation institute focused on the next generation of energy efficient, high-power electronics chips using wide-bandgap semiconductors.