centrotherm SiTec claims improved crystallization furnace process

According to centrotherm photovoltaics subsidiary, centrotherm SiTec has achieved a new cell efficiency record through an improved process in its crystallization furnace to produce multi-crystalline ingots. Further progress has also been claimed in boosting furnace capacity to 650kg without major modifications. Production conditions in a pilot line operation have produced average efficiencies of 16.6%, and a peak result of up to 17.0%, according to the company.

“This achievement underscores the validity of our strategy. Our work is bearing fruit in terms of efficiency enhancements and optimized processes that are accompanied by lower manufacturing costs along the entire solar value-creation chain”, commented Dr. Albrecht Mozer, CEO of centrotherm SiTec. “We are the only fully integrated equipment provider that covers the entire photovoltaic value-creation chain all the way from polysilicon production through to solar cell and module manufacturing. We also adjust the process steps to allow the best possible integration, and we take a very targeted approach to achieving further improvements.”

centrotherm SiTec also said it had reduced the manufacturing costs by 8% with the new crystallization process compared with the previous process sequence. An optimized hot zone for a quartz crucible of 880 mm x 880 mm x 420 mm is employed, which is claimed to enable more efficient silicon smelting. An optimized crystallization process management system is also used.

At the module level, the company claims that the improved process led to 236Watt peak (Wp) modules, which would usually stand at market levels from 210 to 220Wp using ‘standard’ 16.2% and 16.4% multi-crystalline ingot material.