Massachusetts-based start-up 1366 Technologies says its proprietary Direct Wafer process has demonstrated the ability to grow a so-called “three dimensional” wafer, a thin silicon wafer with a thick border – an advancement the company claims is impossible with conventional ingot-based production technologies.
According to 1366, the 3D feature further reduces the amount of silicon required for each wafer without sacrificing strength, durability or performance, and it allows the crystalline silicon PV supply chain to lower costs while leveraging its existing infrastructure.
“The unique capabilities of our Direct Wafer process are an enabler for the crystalline silicon industry to continue its dominant market share position and deliver progressively lower-cost PV solutions for years to come,” comments Frank van Mierlo, CEO of 1366 Technologies. “The 3D wafer feature allows us to meet the industry’s anticipated need for thinner wafers without compromising existing standards or asking manufacturers to abandon their existing manufacturing lines.”
To decrease the amount of silicon used by photovoltaic wafers, manufacturers have long pursued methods to reduce wafer thickness, according to 1366. The company claims that although wire sawing can be used to produce wafers thinner than the standard 180-200 micron thickness, these thin wafers have reduced mechanical integrity and break during cell fabrication, electrical interconnection and encapsulation in modules.
1366 says its Direct Wafer process has the ability to locally control wafer thickness and provide standard 180-200 micron thickness in stress-critical areas such as the wafer perimeter or ribs where busbar soldering will occur, while reducing thickness to 100-120 microns for the remainder of the wafer. The result cuts silicon consumption to ~1.5 g/W and creates a strong, thin wafer able to withstand typical manufacturing stresses, the company adds.
“The beauty of our Direct Wafer process is that the innovation begets further innovation,” continues van Mierlo. “The ability to access the wafer surface during growth is a tremendous advantage and the source of more innovation to come.”
According to 1366, its Direct Wafer process forms multicrystalline wafers in a single step by pulling them directly from molten silicon instead of using a multi-step process, thus saving on energy and capital equipment. The start-up, which is currently working to open its commercial manufacturing plant in New York, says it would consider commercializing the 3D wafers upon industry demand.