The basic properties of semiconductors are as follows:
Intrinsic semiconductors are structurally characterized by a *** valence bond structure, having forbidden bands, and the number of electrons.
1, *** valence bond structure: the atoms of an intrinsic semiconductor are connected to each other by *** valence bonds to form a crystal structure. The *** valence bond is formed by the electrons between the atoms *** enjoy each other, the strength of this bond is weaker than the ionic bond, but stronger than the metal bond.
2, with a forbidden band: the crystal structure of the intrinsic semiconductor, there is a forbidden band, that is, the energy band gap. The forbidden band is the energy difference between the valence band and the conduction band. When an electron leaps from the valence band to the conduction band, it needs to overcome this energy difference in order to complete the leap.
3, the number of electrons: in intrinsic semiconductors, the number of electrons in the valence band is equal to the number of holes in the conduction band. This is because in the *** valence bonding structure, each atom with the surrounding atoms *** enjoy electrons, the formation of electron pairs, when the electrons from the valence band jump to the conduction band, will leave a hole, the number of holes is equal to the number of electrons.
The main role of semiconductors:
1, electronic components: semiconductor materials can be made into a variety of electronic components, such as diodes, transistors, field effect tubes, integrated circuits and so on. These electronic components play a vital role in electronic devices, such as computers, cell phones, televisions, stereos and so on.
2, optoelectronic devices: semiconductor materials can also be made into a variety of optoelectronic devices, such as photodiodes, phototransistors, optoelectronic switches. These optoelectronic devices in the field of optical communications, lasers, photoelectric sensors, etc. have been widely used.
3, solar cells: semiconductor materials can also be made into solar cells, solar energy into electricity, providing clean energy for mankind.
4, semiconductor lasers: semiconductor materials can also be made into semiconductor lasers, used in medical, communications, materials processing and other fields.