As the PV industry strives to reach terawatt scale, addressing the last remaining cost centres of the crystalline silicon value chain will play a critical role in ensuring that the industry can continue to achieve lower systems costs, and provide the extremely low levelized cost of electricity (LCOE) required to drive the adoption of this form of energy. Wafer manufacturing remains the single largest cost driver in industrial cell production. While incremental improvements, such as diamond wire (DW) sawing, have helped to lower silicon consumption, wafer manufacturing has lacked the significant step change necessary for achieving dramatic cost reduction. Creating silicon wafers directly from the melt, without sawing, has long been recognized as a potential breakthrough technology for PV, as it would: 1) allow more effective silicon utilization; 2) eliminate ingot cropping, squaring and blocking and associated consumables costs; and 3) eliminate the most wasteful, high-cost step in wafer manufacturing – the sawing. This paper discusses Direct Wafer® technology, which achieves the long-sought cost and performance advantages compared with current ingot-based production methods; also discussed are the current technical achievements of this wafering process as it moves into commercialization. Wafers produced directly from the melt have been shown to deliver equal or better solar cell efficiency and module stability. Moreover, the ability to operate at the melt level provides significant opportunity for additional R&D achievements, opening a clear path for future industrial importance.
First published in Photovoltaics International - Volume 40