What is the principle of semiconductors? 20

It is related to the electron shell. Generally speaking, the outermost 4 electrons (4-valent) are stable structures.

The 3-valent substance wants to be stable on its own, so it wants to absorb electrons.

5-valent substances want to be stable, so they want to release electrons.

Normally, 3-valent and 5-valent substances are affected by the conservation of charge and do not absorb and release electrons.

However, once the two substances meet together, on the thin layer of the contact surface, the 5 valence gives 1 electron to the 3 valence, and the outermost shell of the two substances becomes a stable structure of 4 electrons, and the movement of the electrons produces an electric field on the contact surface, and at the same time, it conforms to the conservation of charge, and does not show charge to the outside world.

When a small amount of pentavalent phosphorus-donor element is mixed into the silicon crystal, when forming a covalent bond, each phosphorus atom has an extra valence electron, which is not bound by the covalent bond and becomes a free electron, and this phosphorus atom becomes a positive ion (cannot move).formation of n-shaped bodies; When a small amount of the trivalent element boron-acceptor is doped into a silicon crystal, each boron atom forms a hole due to one less valence electron when forming a covalent bond, which is easily filled by neighboring atoms at room temperature, and the boron atom becomes a negative ion (immobile).A hole is created on the atom to form a p-type.

Both p-type and n-type bodies are electrically neutral because their positive and negative charge numbers are equal.

Well? Just because there are more holes and electrons doesn't mean that the charge is not conserved.

The hole just means that the piece in the structure has one less electron than the rest of the place, but the nucleus there is also less positively charged, doesn't it? The same goes for many electrons.

Let's take a look at analog e-books.

Your problem description is actually a mess ...

According to my understanding of this, it is not the same element as the original semiconductor, so the number of protons in the natural nucleus will also change.

Holes can be used to make electrons flow.

A hole has an electron) No.

The difference between chips and semiconductors: Chips, also known as microcircuits, microchips, and integrated circuits, refer to silicon wafers containing integrated circuits, which are small in size and often part of computers or other electronic devices. Semiconductors are materials that have electrical conductivity between conductors and insulators at room temperature.

Semiconductors are materials that have electrical conductivity between conductor insulators at room temperature. For example, diodes are devices made of semiconductors. A semiconductor is a material whose electrical conductivity can be controlled, from an insulator to a conductor.

Whether from the perspective of technology or economic development, the importance of semiconductors is very huge. The core unit of most of today's electronic products, such as computers, mobile** or digital voice recorders, is closely related to semiconductors.

Development of integrated circuits.

State-of-the-art integrated circuits are at the heart of microprocessors or multi-core processors that can control everything from computers to mobile phones to digital microwave ovens. Although the cost of designing and developing a complex integrated circuit is very high.

But when spread across products that are typically in the millions, the cost per integrated circuit is minimized. The performance of integrated circuits is high because of the short path due to the small size, which allows low-power logic circuits to be used at fast switching speeds.

Semiconductor principle: At a certain temperature, the generation and recombination of electron-hole pairs exist at the same time and reach dynamic equilibrium, and the semiconductor has a certain carrier density and thus a certain resistivity. As the temperature increases, more electron-hole pairs will be generated, the carrier density will increase, and the resistivity will decrease.

Therefore, the main principle of semiconductors is the movement of electrons.

Semiconductor Applications:

Semiconductors are mainly used to make semiconductor devices, there are many types, and the application is extremely wide, and now the bright electronic circuits are basically inseparable from semiconductor devices, the computers and mobile phones we use, the integrated circuits in them are made of semiconductors, mainly using silicon as materials. Semiconductor devices are also used in the circuits of various electrical appliances. It is widely used in power systems (such as thyristors) and optoelectronic fields (lasers, LEDs, CCDs, camera lenses).

At present, the widely used semiconductor materials include germanium, silicon, selenium, gallium arsenide, gallium phosphide, indium antimonide, etc., among which the production technology of germanium and silicon materials is more mature and used more. Components made of semiconductor materials, integrated circuits, etc. are important basic products in the electronics industry, and have been widely used in all aspects of electronic technology. The production and scientific research of semiconductor materials, devices and integrated circuits have become an important part of the electronics industry.

Objects such as germanium, silicon, selenium, gallium arsenide, and many metal oxides and metal sulfides, whose conductivity is between conductors and insulators, are called semiconductors.

Semiconductors have some special properties. For example, the relationship between the resistivity and temperature of semiconductors can be used to make thermistors (thermistors) for automatic control; Its photosensitive and special round digging properties can be used to make photosensitive elements for automatic control, such as photocells, photocells and photoresistors.

Semiconductors also have one of the most important properties, and if trace impurities are properly incorporated into pure semiconductor substances, their conductivity will increase millions of times. This characteristic can be used to manufacture a variety of semiconductor devices for different purposes, such as semiconductor diodes, transistors, etc.

If one side of a semiconductor is made into a p-shaped region and the other side is made into an n-shaped region, a thin layer with special properties is formed near the junction, which is generally called a pn junction. The upper part of the figure shows the diffusion of carriers on both sides of the interface between p-type semiconducting orange refractory and n-type semiconductors (indicated by black arrows). The middle part shows the formation process of the p-n junction, indicating that the diffusion of the carriers is greater than the drift (indicated by a blue arrow, and a red arrow indicates the direction of the built-in electric field).

The lower part is the formation of the PN junction. Represents the dynamic equilibrium of diffusion and drift.

Principle: At very low temperatures, the valence band of the semiconductor is a full band (see band theory), after being thermally excited, some electrons in the valence band will cross the band gap into the space band with higher energy, and the presence of electrons in the band becomes the conduction 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 equivalence.

When electrons conduct electricity, the holes of equal charge move in their opposite direction. They produce directional motion under the action of an external electric field to form macroscopic currents, which are called electron conduction and hole conduction, respectively. This hybrid conduction, which is formed due to the generation of electron-hole pairs, is called intrinsic conduction.

The electrons in the conduction band fall into the holes, and the electron-hole pairs disappear, which is called recombination.

The energy released during recombination becomes electromagnetic radiation (luminescence) or thermal vibration energy of the crystal lattice (heat generation). At a certain temperature, the generation and recombination of electron-hole pairs exist simultaneously and reach dynamic equilibrium, at which point the semiconductor has a certain carrier density and thus a certain resistivity. As the temperature increases, more electron-hole pairs are generated, the carrier density increases, and the resistivity decreases.

The four characteristics of semiconductors: negative temperature characteristics of resistivity, light conductivity effect, photovoltaic phenomenon, and rectification effect.

In 1833, Faraday discovered that the electrical resistance of silver sulfide exhibits different properties from ordinary metals as the temperature changes. Normally, the resistance of a metal increases with increasing temperature, and Faraday found that the resistance of silver sulfide decreases as the temperature rises. This is the first semiconductor phenomenon discovered by mankind to withstand interference.

In 1839, French scientist Alexandre Edmond Becquerel discovered the photovoltaic phenomenon. It is a junction formed by the contact between a semiconductor and an electrolyte, which generates a voltage when exposed to light, which is the second characteristic of semiconductors.

In 1873, the British scientist Smith discovered the phenomenon of weakening the resistance of selenium crystal materials in acres under light, which is the third property of semiconductors.

In 1880, the Hall effect of semiconductors was discovered.

In 1874, Ferdinand Braun of Germany discovered the rectification effect of sulfide semiconductors. In the same year, the rectification effect of copper oxide was also discovered.

Semiconductors and chips are different concepts. Chips are a method of miniaturizing circuits in electronics, typically fabricated on the surface of semiconductor wafers. Semiconductors are burn-up materials that are electrically conductive between conductors and insulators at room temperature.

Semiconductors are widely used in consumer electronics, communication systems, medical instruments, and other fields.

The differences between semiconductors and chips are as follows:

1. The concept is different. A chip is a general term for semiconductor component products, a way to miniaturize a circuit. Semiconductors are materials that have electrical conductivity between conductors and insulators at room temperature.

2. The characteristics are different. A chip is an integrated circuit that manufactures circuits on semiconductor chips. Integrated circuits include chip manufacturing technology and design technology.

3. The functions are different. After the advent of chip transistors, a variety of solid-state semiconductor components were used in large quantities to replace the function and role of vacuum tubes in circuits. Semiconductors are mainly used in radios, televisions, and temperature guns.

4. A chip is an integrated circuit, which is composed of a large number of transistors. All kinds of chips will have different scales, ranging from hundreds of millions of transistors to tens of thousands of transistors. After the chip is powered on, a startup instruction will be generated to start the chip, and then it will always accept new instructions and data to complete the function.