Squeezing Light Out of Silicon

IEEE Spectrum  April 8, 2020
Cubic Si, Ge and SiGe alloys are all indirect-bandgap semiconductors that cannot emit light efficiently. An international team of researchers (the Netherlands, Germany, Austria) has demonstrated efficient light emission from direct-bandgap hexagonal Ge and SiGe alloys. They have shown that by controlling the composition of the hexagonal SiGe alloy, the emission wavelength can be continuously tuned over a broad range, while preserving the direct bandgap. Their experimental findings are in excellent quantitative agreement with ab initio theory. Hexagonal SiGe embodies an ideal material system in which to combine electronic and optoelectronic functionalities on a single chip opening the way towards integrated device concepts and information-processing technologies…read more. Open Access TECHNICAL ARTICLE