Germanium: A True "Semimetallic" Element - Recycling Germanium Waste

I. Basic Properties of Germanium Germanium, as a chemical element, occupies a unique position within the vast family of elements. With an atomic number of 32 and a chemical symbol of Ge, when we consult the periodic table, we find it situated directly below carbon, belonging to Group 14. This positional relationship enables germanium to inherit certain characteristics of the carbon group elements to some extent. At the microscopic level, germanium's outer electron configuration is 4s² 4p², which determines its chemical valence states of four and two. In the macroscopic material world, germanium exhibits a unique appearance as a gray metalloid element. This unique property, situated between metal and non-metal, grants it high chemical reactivity. For instance, when germanium encounters oxygen, a chemical reaction silently occurs, forming germanium dioxide through their interaction. This process vividly demonstrates germanium's chemical reactivity.II. Metallic Properties of Germanium Germanium's electron configuration shares many similarities with silicon, which accounts for their numerous commonalities in physical properties. However, germanium possesses distinct differences from silicon, particularly in its more pronounced metallic nature compared to silicon. Under special environmental conditions such as high temperatures, germanium seems to unleash its metallic potential, exhibiting conductivity and thermal conductivity similar to metals. Imagine in a high-temperature furnace, electricity flows freely within germanium like agile dancers, while heat rapidly transfers through its crystal lattice structure, akin to efficient relay race athletes. It is based on these prominent metallic properties at high temperatures that scientists classified germanium as a metal element in early periodic tables, reflecting the preliminary stage of understanding its properties at that time.III. Semiconductor Properties of Germanium Despite possessing metallic properties, when we delve deeper into its electronic band structure, we discover that germanium has a closer connection with semiconductors. In contrast to the continuous energy bands of metal electrons, the energy bands in semiconductors present discrete, separated regions, with a crucial area existing between these bands—the band gap. Germanium's band structure features a very narrow band gap. This seemingly insignificant band gap has a crucial impact on germanium's electrical properties, enabling it to perfectly exhibit semiconductor properties in terms of electrical characteristics.