The CZ method of crystal pulling is used for producing large amounts of dislocation-free silicon economically for semiconductor device and photovoltaic conversion applications.
To reduce the cost and improve further the quality of n-type mono silicon crystal, SunEdison has developed a continuous Czochralski (CCZ) crystal pulling process, based on the technology of Solaicx, acquired in 2010.
Single-crystal silicon is extensively utilized in the photovoltaic sector for the production of solar panels , with Czochralski growth being the main approach for the growth of the photovoltaic single-crystal silicon .
The strong demand on silicon requires wafer manufacturers to produce high-quality material through high productivity processes with low-cost. Due to the higher energy conversion efficiency of single crystalline silicon (sc-i), the Czochralski (Cz) pulling remains the key technology in photovoltaics.
During crystal pulling, the conductivity type, wafer resistivity, and main defect properties are fixed. The crystals are grown according to a specific crystallographic orientation, which mostly but not always corresponds to the final wafer orientation.
Future high efficiency silicon solar cells are expected to be based on n-type monocrystalline wafers. Cell and module photovoltaic conversion efficiency increases are required to contribute to lower cost per watt peak and to reduce balance of systems cost.