Prototype modules featuring ‘3D wafers’ on show at SNEC

Prototype modules featuring 1366 Technologies’ 3D direct wafers were on show this week at the SNEC show in Shanghai, the fruit of a partnership between the U.S-based wafer startup and module manufacturer Hanwha Q Cells.

According to 1366, the modules feature Q Cells’ PERC based Q.ANTUM technology, and have an expected power rating of 360 W. A company representative told pv magazine 1366’s technology roadmap anticipates efficiencies higher than 22% and the startup’s work to date indicates moving to thinner wafer designs can lead to better power output.

Massachusetts-based 1366 produces wafers using an epitaxial process – directly from molten silicon rather than being sawn from an ingot, which is the standard industrial method. That allows the manufacturer to vary the thickness of the wafer, reducing the amount of silicon required per piece. According to 1366, the wafers showcased at SNEC are an average of 130 microns thick – and in mass production could be as thin as 110 microns. The wafers are made with a thicker border measuring the industry standard 180 microns to protect against breakage in later stages of production.

Tumbling wafer prices have left producers such as 1366 chasing a moving target as they try to disrupt the established diamond wire cutting process. However the company believes pursuing its goal of reducing silicon utilization in wafer manufacturing to less than 1.5g per watt will bring prices even lower.

“Earlier this year, in response to the rapid wafer price decline, 1366 made a strategic decision to accelerate the timeline for the 3D wafer feature,” said Adam Lorenz, chief technology officer of the business, which is based in the town of Bedford. “The most vital metrics in solar are cost and performance and the 3D wafer feature allows innovative manufacturers like Q Cells to deliver the industry’s best price-performance ratio.”

Factory nears completion

Hanwha Q Cells and 1366 Technologies are ramping up a factory near the Korean company’s cell and module fabs in Malaysia. The factory is set to come online in the third quarter, according to announcement made by 1366 in February.

Wafers for the prototype modules were produced at Q Cells’ Center for Technology Innovation and Quality in Thalheim, Germany. Aside from the wafers, the modules were assembled in a six-busbar, 144 half cell format using components identical to those used in Q Cells’ commercial production. “Thin wafers compatible with existing automation and equipment have long been an industry goal,” said Q Cells chief technology officer Ji Weon Jeong, “but are beyond the capabilities of mainstream wafer technologies.”