The Egyptian researcher Elham Fadaly , her colleagues at Eindhoven University of Technology in the Netherlands , others from Friedrich-Schiller-Universität Jena in Germany and an international team won the Physics World 2020 Breakthrough of the Year for creating a silicon-based material with a direct band gap that emits light at wavelengths used for optical telecommunications.
In the Top 10 Breakthroughs of 2020, Nine other achievements are highly commended.
Saying that finding a silicon-based material that emits useful light has been the Holy Grail of optoelectronics. Normally, silicon has an indirect electronic bandgap, which means that it does not emit light is no exaggeration.
To create the optoelectronic devices that supply the pulses of light that drive information on the Internet, silicon must be integrated with other direct-band-gap semiconductor materials.
Fadaly and colleagues had to find a way of growing crystals of silicon-germanium alloy with a hexagonal crystal structure, rather than the usual diamond-like structure to create a direct band gap.
They created nanowires of the alloy, which emitted infrared light to do so. As well as having applications in optical telecoms and optical computing, the new silicon-based material could be used to create chemical sensors.