A semiconductor (semiconductor) refers to the material that is between the conductor (conductor) and the insulator (insulator) at normal temperature. Semiconductors have a wide range of applications in radio, television and temperature measurement. A diode is a device made of semiconductors. Semiconductors are materials that can be controlled by electrical conductivity, ranging from insulators to conductors. The importance of semiconductors is very huge in terms of science and technology and economic development. Most of today's electronic products, such as computers, mobile phones, or the core units of digital recorders, are closely related to semiconductors. The common semiconductor materials are silicon, germanium, gallium arsenide and so on, and silicon is one of the most influential commercial applications in all kinds of semiconductor materials.