Metalloid what classification criteria are used. Emsley recognised four metalloids (germanium, arsenic, antimony, and tellurium); James et al. listed twelve (Emsley's plus boron, carbon, silicon, selenium, bismuth, polonium, moscovium, and livermorium). On average, seven elements are included in such lists; individual classification arrangements tend to share common ground and vary in the ill-defined margins. A single quantitative criterion such as electronegativity is commonly used, metalloids having electronegativity values from 1.8 or 1.9 to 2.2. Further examples include packing efficiency (the fraction of volume in a crystal structure occupied by atoms) and the Goldhammer-Herzfeld criterion ratio. The commonly recognised metalloids have packing
Germanium-tin have already been demonstrated. In addition, germanium-tin light emitting diodes operating at room temperature have also been reported. Germanium-tin Germanium-tin is an alloy of the elements germanium and tin, both located in group 14 of the periodic table. It is only thermodynamically stable under a small composition range. Despite this limitation, it has useful properties for band gap and strain engineering of silicon integrated optoelectronic and microelectronic semiconductor devices. Germanium-tin alloys must be kinetically stabilized in order to prevent decomposition. Therefore, low temperature molecular beam epitaxy or chemical vapor deposition techniques are typically used for their synthesis. Germanium-tin alloys have