Flexible display substrate material (PI)
Semiconductor materials are electronic materials that have semiconductor properties (conductivity is between conductors and insulators, and the resistivity is approximately in the range of 1mΩ·cm to 1GΩ·cm) that can be used to make semiconductor devices and integrated circuits.
Nature's substances and materials can be divided into three categories: conductors, semiconductors and insulators according to their electrical conductivity. The resistivity of the semiconductor is in the range of 1mΩ·cm～1GΩ·cm (the upper limit is set according to Xie Jiakui's "Electronic Circuits", and there are 1/10 or 10 times of it; because the corner mark is not available, the current description is temporarily used). The conductivity of semiconductors increases with increasing temperature, which is exactly the opposite of metal conductors.
All materials with the above two characteristics can be classified into the scope of semiconductor materials. Reflect semiconductor
Intrinsically basic properties are physical effects and phenomena caused by various external factors such as light, heat, magnetism, and electricity acting on semiconductors. These can be collectively referred to as the semiconductor properties of semiconductor materials. Most of the matrix materials that constitute solid-state electronic devices are semiconductors, and it is the various semiconductor properties of these semiconductor materials that give various types of semiconductor devices different functions and characteristics. The basic chemical characteristic of semiconductors is the existence of saturated covalent bonds between atoms. As a characteristic of covalent bonds, it is a tetrahedral structure in the lattice structure, so typical semiconductor materials have the structure of diamond or zinc blende (ZnS).
Since most of the earth’s mineral deposits are compounds, the semiconductor materials that have been used early are all compounds. For example, galena (PbS) was used for radio detection early, cuprous oxide (Cu2O) was used as a solid rectifier, and sphalerite (ZnS) It is a well-known solid-state luminescent material, and the rectification detection effect of silicon carbide (SiC) has also been used earlier. Selenium (Se) is an elemental semiconductor discovered and used early, and was once an important material for solid rectifiers and photovoltaic cells. The discovery of the elemental semiconductor germanium (Ge) amplification has opened a new page in the history of semiconductors, and since then electronic devices have become transistorized. China's semiconductor research and production began with the preparation of high-purity (99.999999% to 99.9999999%) germanium in 1957. The use of elemental semiconductor silicon (Si) not only increased the types and varieties of transistors and improved performance, but also ushered in the era of large-scale and ultra-large-scale integrated circuits. The discovery of III-V compounds represented by gallium arsenide (GaAs) has promoted the rapid development of microwave devices and optoelectronic devices.