Sharp Corp announced a new technology that can reduce wafer production cost by 50% in its presentation titled "New Wafer Technology for Crystalline Silicon Solar Cell" at the EU PVSEC.
The company has already set up an automation line with belt conveyors, etc. And the presenter claimed that it is "a technology on the mass-production level."
In the new production method, a substrate is first brought into contact with molten silicon so that Si is attached to the substrate surface. Then, the attached silicon is peeled off to obtain a Si sheet, and the circumference of the sheet is removed by using a laser to adjust the size. The silicon removed by the laser is reused after being melted again.
In the presentation, the company said that it would not detail the method to peel off the attached silicon although it showed a video to explain the production flow.
After 10 years of development, the company succeeded in achieving a high throughput of 1,825cm2/min for a large cell size of 156 x 156mm. The new technique enables to produce one wafer in eight seconds.
The cell is 300μm thick. The new technique reportedly reduces the production cost by 50%, compared with a case using the existing casting process to manufacture cells with a thickness of about 200μm. The cells made with the new technology have a conversion efficiency of 14.8% as of 2006, although the company did not reveal the current value.
Meanwhile, a module composed of 42 cells achieved the maximum output of 144W.