Product Briefing Outline: Silicon Genesis has successfully produced solar substrates for the PV industry using its ‘kerf-free’ wafering process technology called ‘PolyMax’. The company has started production of the first ever kerf-free 150um solar-cell substrates at its new solar development and pilot production facility. In addition to saving poly, the wafers are claimed to be significantly more resistant to breakage than conventional wafers using its proprietary equipment.
Problem: The Solar market provides an especially large and interesting opportunity for SiGen. Today, there are two primary types of solar cells – – thin film and thick film. The thin film cells have excellent silicon utilization, but suffer from poor conversion efficiency. The thick films have typically high conversion efficiencies, but require excessive amounts of precious silicon. SiGen’s layer transfer technology provides for thin films with good efficiencies. SiGen’s layer transfer process is a ‘green’ process since there is no sawing, grinding or other mechanical thinning of wafers. Today silicon is the major (approx 60%) cost component of solar cells. With SiGen’s layer transfer process, the cost of producing solar cells with high efficiencies will be dramatically reduced, further stimulating an already exploding market.
Solution: By eliminating sawing losses, the PolyMax equipment set can substantially reduce the amount of polysilicon used within the ingot to wafer manufacturing steps and also eliminate some of the costly consumables in today’s wafer manufacturing. The kerf-free nature of the PolyMax system is claimed to halve the silicon feedstock material required to manufacture the same amount of MW capacity per year. First targeted to process monocrystalline silicon to produce high-efficiency silicon solar cells, the equipment is expected to help the PV industry reach grid parity while simultaneously relaxing the shortage of polysilicon feedstock. The company has produced 50-micron thick, full-size 125mm wafer samples utilizing engineering equipment with excellent mechanical and electrical characteristics. SiGen plans to start pilot line operations by spring 2009 that demonstrate kerf-free processing of silicon ingots into wafers ranging from 150um to 50um in thickness.
Applications: Monocrystalline wafers ranging from 150um to 50um in thickness.
Platform: First targeted to process monocrystalline silicon to produce high-efficiency silicon solar cells, the equipment is expected to help the PV industry reach grid parity while simultaneously relaxing the shortage of polysilicon feedstock.
Availability: 125mm wafers are in production. 156mm wafers will be offered soon.
