The thermal expansion shear separation (TESS) technique for producing thin self-supporting silicon films for low-cost solar cells

A new technique-Thermal Expansion Shear Separation (TESS)- is described for producing thin self-supporting polycrystalline silicon ribbons using temporary molybdenum substrates. The TESS substrates and separated silicon ribbons were characterized to determine the shear separation mechanism, limits to substrate recyclability, and the quality of the silicon ribbon for efficient solar-cell fabrication. Solar cells fabricated on the silicon ribbons separated from molybdenum substrates have exhibited AM1 conversion efficiencies of up to 11.8 percent after ribbon-to-ribbon (RTR) grain enhancement. By recycling the Mo substrate its cost contribution can be as low as $0.0074/peak watt of electricity produced.