| Work Detail |
A German-Algerian research team has been investigating ways to produce silicon from diatomite, a fossil material containing amorphous silicon dioxide. The researchers say that for potential applications in solar cells, it will be crucial to extract silicon with a low level of impurities.
Diatomaceous earth, also known as diatomite, has been used as a material for liquid filters since the 19th century. It is also used in the manufacture of thermal insulation materials, grinding and polishing agents, cleaning products and insect repellents.
The use of this material could be extended to the manufacture of solar cells, according to a group of researchers from the HAWK University of Applied Sciences and Arts in Hildesheim/Holzminden/Göttingen (Germany) and the Algerian University of Oran.
The sediment consists largely of fossil diatom shells containing amorphous silicon dioxide. The extraction of diatomite in northern Germany began around 1840 and was discontinued in 1994. Until the beginning of the 20th century, the deposits covered almost all of the worlds demand, and later the material was also mined in many other countries. Today, there are large deposits in the USA, Denmark, Turkey and China.
The scientists explained that the detection of impurities in diatomite will be a critical issue during the silicon extraction process, noting that impurities can significantly affect the performance of silicon solar cells.
To solve this problem and evaluate the quality of diatomite, they applied a calibration-free laser-induced breakdown spectroscopy (LIBS) measurement methodology with improved sensitivity.
The researchers also evaluated the morphology and surface properties of the diatomite using energy-dispersive X-ray spectroscopy and scanning electron microscopy.
Their findings are available in the study “ Quantification of impurities in diatomite via sensitivity- improved calibration-free laser-induced breakdown spectroscopy,” published in the Journal of Analytical Atomic Spectrometry . “This research contributes to the optimization of the manufacturing process of electronic-grade silicon from diatomite for photovoltaic technology and other applications,” they conclude. |
