In recent years, Germanium it has been found that two-dimensional materials have a very peculiar and excellent frictional properties due to their special planar atomic structure, Germanium and are expected to be an important application in the field of micro-nano as an ultra-thin lubricating material. However, due to the extraordinary surface area of the two-dimensional film material, it is easy to reduce or even lose the lubricating performance due to the influence of the working environment, especially the surface chemistry. Therefore, how to effectively maintain the stability of monomolecular two-dimensional materials from the atomic scale in complex sliding conditions gives the researchers a new challenge. Researchers have observed that the polycrystalline graphene grown on the germanium (111) crystal plane, Germanium due to the different ways of stacking up and down crystals, produces both regions with periodic moiré fringes and non-moire fringes. After fluoride, oxidation and other chemical treatment, Germanium non-Moer stripe regional lubrication performance greatly weakened. However, graphene with periodic moiré fringes still retains good lubricity. It is found that the interaction between the carbon atoms of the graphene and the germanium atoms in the periodic moiré fringe is much stronger than that of the ordinary van der Waals force. Germanium The strong anchoring The role of graphene can resist the external disturbance of its flat molecular structure of the change, thereby enhancing its lubrication of the robustness. Germanium The related research found that it is expected to be extended to other two-dimensional material systems to promote the application of monolayer lubricating materials in micro-nano systems.
SOI Materials Group for the first time in 2013 to achieve a germanium-based substrate CVD growth of large-size continuous monolayer graphene (Sci. Rep. 3 (2013), 2465). On the basis of this, Germanium the application of germanium-based graphene is studied deeply. It is found that there is a good interfacial property between graphene and the substrate. When the graphene is subjected to unilateral fluorination, Germanium the fluorinated graphene is not only high Compactness and structural strength, and can be transformed from metallic semiconductors to two-dimensional insulating materials. Thus, fluorinated graphene is innovatively used as an interface passivation layer in a germanium-based MOSFET device. The results show that Fluorinated graphene can effectively inhibit the interfacial interdiffusion behavior, especially the formation of charge traps caused by the diffusion of oxygen atoms to germanium base substrates, Germanium avoiding unstable oxides and interface defects. MOS device performance is greatly improved, Germanium the gate leakage current can be reduced by 4-5 orders of magnitude and can reduce the equivalent oxide thickness to below 1nm. The research work will provide a solution for the replacement of silicon materials by germanium materials, Germanium the promotion of microelectronics technology into the non-silicon CMOS era, and the continuation of the development of Moore's Law.
Germanium, tin and lead in the periodic table is the same family, the latter two have long been discovered and used by ancient people, Germanium and germanium for a long time has not been industrial-scale mining. This is not due to the low content of germanium in the crust, Germanium but because it is one of the most dispersed elements in the crust, germanium-containing ore is very small.
Germanium is widely distributed in nature. Copper, iron ore, sulfide ore and rock, Germanium soil and spring water contains trace amounts of germanium. The content of germanium in the crust is seven parts per million, which is less than the common elements of oxygen, silicon and so on, Germanium but it is more than arsenic, uranium, mercury, iodine, silver and gold. However, germanium is very scattered, almost no more concentrated germanium ore, therefore, is known as "thin metal." Found germanium ore sulfur silver germanium ore (containing germanium 5 ~ 7%), germanium stone (containing germanium 10%), sulfur copper iron germanium ore (germanium 7%). Germanium ore germanium content of 200ppm and 393ppm two, Germanium the color is gray, red color two.