Kerf-free wafering: Technology overview and challenges for thin PV manufacturing

Eliminating high absorber material loss while allowing thin and ultra-thin crystalline silicon PV has been a “Holy Grail” of the crystalline silicon PV industry for decades. Generally called “kerf-free wafering”, the fundamental approach is to substitute slurry saws with an alternative waste-free wafering technology. Ideally, the technology would also eliminate the difficulty to process thin to ultra-thin wafers inherent to slurry saws. Should such an alternative method become practical and compatible with high-volume PV wafering operations, the potential cost savings are first-order with game-changing implications for the PV industry and competing thin-film approaches. Due to the recent scarcity of purified polysilicon feedstock and module price erosion, there has been renewed interest in identifying and developing kerf-free wafering approaches [1,2]. Industrializing kerf-free wafering technology has, however, proven challenging. Most technologies have only been demonstrated at the small lab-scale without surmounting practical or technical issues to move to high-volume manufacturing operations. This paper will present an overview of the various generation. The resulting growth is predicted to exceed 35% CAGR over the next decade. technology alternatives to wafering for PV applications, achieve efficient absorber absorbers grown in either absorbers singulated with a crystalline silicon kerf-free The two main approaches to material utilization are (i) gas or liquid phase or (ii) near-zero kerf technology. Specific technologies within each major category will be described and rated for their ability to effectively ramp to industrial scale production. These approaches will be reviewed as to cost, energy expended per wafer, kerf reduction, absorber quality, ability to wafer ultra-thin PV absorbers, high-volume manufacturing compatibility and time to ramp to industrial scale production.