© Thomas Shiell and Timothy Strobel
Visualization of the structure of 4H-Si viewed perpendicular to the hexagonal axis. A transmission electron micrograph showing the stacking sequence is displayed in the background.
Washington, DC — A team led by Carnegie's Thomas Shiell and Timothy Strobel
developed a new method for synthesizing a novel crystalline form of silicon with a hexagonal structure that could potentially be used to create next-generation electronic and energy devices with enhanced properties that exceed those of the "normal" cubic form of silicon used today.
Their work is published in
Physical Review Letters.
Silicon plays an outsized role in human life. It is the second most abundant element in the Earth's crust. When mixed with other elements, it is essential for many construction and infrastructure projects. And in pure elemental form, it is crucial enough to computing that the longstanding technological hub of the U.S. — California's Silicon Valley — was nicknamed in honor of it.
Like all elements, silicon can take different crystalline forms, called allotropes, in the same way that soft graphite and super-hard diamond are both forms of carbon. The form of silicon most commonly used in electronic devices, including computers and solar panels, has the same structure as diamond. Despite its ubiquity, this form of silicon is not actually fully optimized for next-generation applications, including high-performance transistors and some photovoltaic devices.
While many different silicon allotropes with enhanced physical properties are theoretically possible, only a handful exist in practice given the lack of known synthetic pathways that are currently accessible.
Comment: For further insight into how this strengthens the case for cyclical cometary events as the cause of catastrophic "geologic events", like volcanic eruptions, see: