Silicon is the second most-abundant element in the Earth's crust. When purified, it takes on a diamond structure, which is essential to modern electronic devices--carbon is to biology as silicon is to technology. A team of Carnegie scientists including EFree Associate Director Timothy Strobel and EFree Research Scientist Duck Young Kim has synthesized an entirely new form of silicon, one that promises even greater future applications. Although silicon is incredibly common in today's technology, its so-called indirect band gap semiconducting properties prevent it from being considered for next-generation, high-efficiency applications such as light-emitting diodes, higher-performance transistors and certain photovoltaic devices.
The silicon they created is a so-called allotrope, which means a different physical form of the same element, in the same way that diamonds and graphite are both forms of carbon. Unlike the conventional diamond structure, this new allotrope consists of an interesting open framework, called a zeolite-type structure, which is comprised of channels with five-, six-and eight-membered silicon rings. They created it using a novel high-pressure precursor process.