Why do electronic components use semiconductor materials?

Semiconductors are used in integrated circuits, consumer electronics, communications systems, photovoltaic power generation, lighting applications, high-power power conversion and other fields. A semiconductor is a material between a conductor and an insulator. But semiconductor insulators and conductors do not have a feature is, it is used as the substrate, the characteristic of two different to combine these two kinds of substrate together can reflect the nature of insulation and conductor alternating, such as diode reverse insulation, positive conductive, transistor controlled by a side can make its electrical conductive, let its insulation insulation.

The role of semiconductor is to change the local impurity concentration to form some device structure, which has a certain control effect on the circuit, such as one-way conduction of diode, such as amplification of transistor.

Semiconductor classification and performance

(1) Element semiconductor. It is a solid material that has the same elemental semiconductor properties and is susceptible to changes caused by trace impurities and external conditions. At present, only silicon and germanium have good properties and are widely used. Selenium is used in electronic lighting and photovoltaics. Silicon is widely used in the semiconductor industry, mainly affected by silicon dioxide, can form a mask in device production, can improve the stability of semiconductor devices, is conducive to automatic industrial production.

(2) inorganic composite semiconductor. Inorganic composites are mainly composed of a single element as a semiconductor material. Of course, there are also semiconductor materials made up of many elements. The main semiconductor characteristics are groups I and V, VI and VII. Groups II and IV, V, VI and VII; Group III and V, VI; IV and IV, VI; V and VI. VI and VI combination of compounds, but due to the influence of element characteristics and production methods, not all compounds can meet the requirements of semiconductor materials. The semiconductor is mainly used in high-speed equipment. InP makes transistors faster than other materials and is mainly used in optoelectronic integrated circuits and anti-radiation equipment. For materials with high conductivity, they are mainly used in leds and other aspects.

Why do electronic components use semiconductor materials?(3) Organic compound semiconductor. Organic compounds are compounds that have carbon bonds in their molecules. Organic compounds and carbon bonds are perpendicular to each other to form conducting bands. By chemical addition, it can enter the band, which produces electrical conductivity and forms organic compound semiconductors. Compared with previous semiconductors, the semiconductor is characterized by low cost, good solubility and ease of processing lightweight materials. Conductivity can be controlled by controlling molecules, with a wide range of applications, mainly used in organic films, organic lighting and so on.

(4) amorphous semiconductor. It is also known as amorphous semiconductor or glass semiconductor, belongs to a class of semiconductor materials. Like other amorphous materials, amorphous semiconductors have short-range ordered and long-range disordered structures. It forms amorphous silicon mainly by changing the relative positions of atoms and changing the original periodic arrangement. Crystalline and amorphous states differ mainly from whether the atoms are arranged in long order. It is difficult to control the performance of amorphous semiconductors. With the invention of the technology, amorphous semiconductors began to be used. The production process is simple, mainly used in engineering field, good light absorption effect, mainly used in solar cells and LIQUID crystal display.

(5) intrinsic semiconductor. Semiconductors free of impurities and lattice defects are called intrinsic semiconductors. At very low temperatures, the semiconductor valence band is full. After thermal excitation, some electrons in the valence band will cross the forbidden band and enter the empty band at higher energies. The electrons in the empty band become the conduction band. No electrons will form a positive-charged vacancy called a hole. Hole conduction is not an actual motion, but an equivalent motion. When electrons conduct, holes with equal charge will move in opposite directions. [5] They generate directional motion under the action of an external electric field to form a macroscopic current, called electron conduction and hole conduction respectively.

This mixed conductivity through the generation of electron-hole pairs is called intrinsic conductivity. The electrons in the conduction band fall into the hole and the electron-hole pair disappears, which is called recombination. The energy released during reorganization becomes electromagnetic radiation (luminescence) or lattice thermal vibration energy (heating). At a certain temperature, the generation and recombination of electron-hole pairs exist simultaneously and reach dynamic equilibrium. At this point, the semiconductor has a certain carrier density and therefore a certain resistivity. As the temperature increases, more electron-hole pairs are created, the carrier density increases, and the resistivity decreases. Pure semiconductors without lattice defects have relatively high resistivity.

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