By Sebastian Liebischer, Member of the Process Development Unit, Wacker Chemie AG; Dieter Weidhaus, Project Engineer, Wacker Chemie; Dr. Tobias Weiss, Member of the Process Development Unit, Wacker Chemie AG
The photovoltaic market, which is dominated by polysilicon-based crystalline solar cells, has been developing rapidly, with growth rates in the double-digit range for several years. In order to meet increasing demand for hyperpure polysilicon, manufacturers need to adhere to environmentally-friendly production processes with low energy consumption. This article highlights the key processes needed to manufacture hyperpure polycrystalline silicon and explores the related challenges and solutions for sustainable polysilicon production. Our findings prove that only an intelligent interaction of all necessary process steps fulfils the requirements for minimized production residue volumes and low energy consumption. Totally integrated production loops for all essential media are prerequisite to reach these targets. Once implemented, these highly efficient production processes serve as an excellent platform technology for the continued healthy growth of the PV industry.