The industrial material production process is very hard on silicon wafers. In fact, between 5 and 10% of these expensive wafers used to make photovoltaic solar cells are damaged during the process, translating annually into billions of lost dollars by the solar industry.
Researchers at the National Renewable Energy Laboratory (NREL) have created a Silicon Photovoltaic Wafer Screening System that identifies damaged wafers before they are installed in solar cells in order to stop the manufacturing of defective ones. By exposing wafers to high temperatures, the thermal stress serves to test the weak and defective wafers which and then be flagged and removed from the solar cell production process.
1200 wafers can be tested per hour using the manual version of NREL’s $60,000 instrument. There is also an automated version which can remove the detected defective wafers and separate them into a container for later melting and recycling back into materials used to make wafers.
Manufacturers could use this tool to improve their quality control measures which would ultimately save money and reduce consumer cost. The more cost-competitive solar cells become, the more marketable they are. In fact, researchers have determined the main deterrent consumers cite for not using commercial solar photovoltaic systems is cost.
