US scientists discovered the ability of a special form of silicon to both conduct electricity, and absorb and emit light. The unique property of the element makes it extremely suitable for use in new generation solar cells and LED lights.
This form of silicon is not the one that we find in great abundance in the environment around us. It is the Si24, a diamond-structured form, created by a team of talented scientists at Carnegie Institution for Science, led by Timothy Strobel. In order to end up with Si24, the scientists had to conduct a great deal of lab experiments and go through various lengthy and resource-consuming processes, but it all paid off in the end.
In a nutshell, the procedure was as follows. The team had to first produce a compound out of sodium and silicon (Na4Si24). This compound was then placed in a tantalum capsule and exposed to high temperature and pressure. Once the pressure reached 10 gigapascals, the compound was placed in vacuum at 400 K temperature for a week, which is just enough time for Si24 to form.
In their study published in the latest issue of Nature Materials, the team explains how this form of silicon has a unique property that has never been observed before with any other material. It can conduct electricity much more efficiently than any other form of silicon, while at the same time it can emit and absorb light. This ability is achieved thanks to the so-called quasi-direct band gap within the structure.
The scientists see a great potential of their discovery, especially in the field of renewable energy. According to the guys, it paves the way to a whole new and exciting research in novel energy materials. The fact that it can remain intact under super high pressure and temperature makes it even more exciting to work with. The industries that could make the most use of Si24 are solar cell development and LEDs.
Image (c) Timothy Strobel
