This new method transforms agricultural waste into state-of-the-art light-emitting diodes in a low-cost, environmentally friendly way.
Milling rice to separate the grain from the husks typically produces about 100 million tons of rice husk waste globally each year.
“Since typical QDs often involve toxic material, such as cadmium, lead or other heavy metals, environmental concerns have been frequently deliberated when using nanomaterials. Our proposed process and fabrication method for QDs minimises these concerns,” said Ken-ichi Saitow, lead study author and a professor of chemistry at Hiroshima University.
The technology makes use of porous silicon (Si), a material that is non-toxic and found abundantly in nature with photoluminescence properties, stemming from its microscopic (quantum-sized) dot structures that serve as semiconductors. Waste rice husks have been found to an excellent source of high-purity silica (SiO2) and value-added Si powder.
The...