OPTIMIZATION OF TEMPERATURE, CONCENTRATIONS AND TYPES OF SOLUTIONS IN SILICON PHOTOVOLTAIC SOLAR CELLS AND MODULES RECYCLING

Photovoltaic solar modules manufacturers use monocrystalline and polycrystalline silicon solar cells, produced in different technologies, which - in the effect - vary between them. Differences are evident particularly for metallization. When making crystalline Si solar cells, Al, Ag metallization and Ag/Al are widely used in order to reduce the electrical resistance of the contact fingers. For the reusability of silicon crystalline solar cells from the used or damaged modules the most important stage, due to requested high quality of materials - is chemical treatment. The process regimes had to be developed in such a way that the high electric properties of the silicon were conserved. In case of crystalline silicon cells, the metallization, antireflective coating and p/n-junction could be removed subsequently by etching. Consequently there is no universal recipe which could be applied generally. The etching recipes have to be adapted to different cell technologies. The main point of the chemical treatment of the thermally separated solar cells and of solar silicon wastes lies in the development of resources protection and environmentally-friendly cleaning processes. The organization of the process conditions arises as a scientific aim from it in line with the economy of the disposal of the applied chemicals. In this article the results of the newer etching mixtures examinations for the silicon crystalline cells have been presented.