semiconductor refers to a material whose electrical conductivity at room temperature is between a conductor and an insulator. Semiconductors are widely used in radio, television and temperature measurement. Diodes, for example, are devices made of semiconductors. A semiconductor is a material whose electrical conductivity can be controlled, ranging from insulator to conductor. Whether from the perspective of technology or economic development, the importance of semiconductors is very huge. The core units in most of today's electronic products, such as computers, mobile phones or digital recorders, are closely related to semiconductors. Common semiconductor materials are silicon, germanium, gallium arsenide, etc., and silicon is one of the most influential in commercial applications among various semiconductor materials.

semiconductor refers to a material whose electrical conductivity at room temperature is between a conductor and an insulator. Semiconductors have a wide range of applications in radio, television and temperature measurement, integrated circuits.

Matter exists in many forms, solid, liquid, gas, plasma, etc. Materials with poor electrical conductivity, such as coal, artificial crystals, amber, ceramics, etc., are usually called insulators. The relatively good electrical conductivity of metals such as gold, silver, copper, iron, tin, aluminum and so on called conductors. The material between a conductor and an insulator can simply be called a semiconductor. Compared with conductors and insulators, the discovery of semiconductor materials is the latest, until the 1930s, when the purification technology of materials improved, the existence of semiconductors was really recognized by the academic community.

Intrinsic semiconductor: A semiconductor that does not contain impurities and has no lattice defects is called an intrinsic semiconductor. At very low temperatures, the valence band of the semiconductor is full band (see band theory), after being thermally excited, some electrons in the valence band will cross the forbidden band into the empty band with higher energy, the empty band becomes a conduction band after the presence of electrons in the valence band, and the lack of an electron in the valence band forms a positively charged vacancy, called a hole. Hole conduction is not an actual motion, but an equivalent. When the electron conducts electricity, the hole of equal charge will move in its opposite direction. They produce directional motion under the action of external electric field and form macroscopic current, which are called electron conduction and hole conduction respectively. This type of hybrid conduction due to the generation of electron-hole pairs is called intrinsic conduction. The electrons in the conduction band will fall into the hole, and the electron-hole pair will disappear, which is called recombination. The energy released during recombination becomes electromagnetic radiation (luminescence) or thermal vibration energy (heating) of the lattice. At a certain temperature, the generation and recombination of electron-hole pairs exist at the same time and reach dynamic equilibrium, at which time the semiconductor has a certain carrier density and thus a certain resistivity. When the temperature increases, more electron-hole pairs will be produced, the carrier density will increase, and the resistivity will decrease. Pure semiconductors without lattice defects have high resistivity and few practical applications.