What are the classifications of semiconductor devices? What are the semiconductors

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 characteristics 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.

When one side of a semiconductor is made into a p-type region and the other side is made into an n-type region, a thin layer with special properties is formed near the junction, which is generally called a p-n junction. The upper part of the figure shows the diffusion of carriers at the interface between p-type semiconductors 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.

There are many semiconductor materials, which can be divided into two categories: elemental semiconductors and compound semiconductors according to their chemical composition. Germanium and silicon are the most commonly used elemental semiconductors; Compound semiconductors include group and group compounds (gallium arsenide, gallium phosphide, etc.), group and group compounds (

cadmium sulfide, zinc sulfide, etc.), oxides (oxides of manganese, chromium, iron, copper), and solid solutions consisting of - and - compounds (gallium aluminum arsenic, gallium arsenic phosphorus, etc.). In addition to the above-mentioned crystalline semiconductors, there are also amorphous glass semiconductors and organic semiconductors.

The classification of semiconductors can be divided into integrated circuit devices, discrete devices, optoelectronic semiconductors, logic ICs, analog ICs, memories and other categories according to their manufacturing technology, and generally these will be divided into subcategories. In addition, there are methods to classify by application field, design method, etc., and although they are not commonly used, they are classified by IC, LSI, VLSI (very large LSI), and their size.

In addition, there are methods that can be divided into analog, digital, analog-digital mixture, and function according to the signal they process.

1. N-type semiconductors.

N-type semiconductors are also known as electronic-type semiconductors.

i.e. free electrons.

Impurity semiconductors whose concentrations are much greater than the hole concentrations.

Principle of formation. Both doping and defects can cause conduction bands.

An increase in the concentration of electrons in the medium. For germanium, silicon semiconductor materials.

Doped group elements, when the impurity atoms replace the germanium and silicon atoms in the crystal lattice in a substitution manner, they can provide a covalent bond that satisfies the difference.

An extra electron outside of the coordination, which creates an increase in the concentration of conduction band electrons in the semiconductor, this class of impurity atoms is called the donor. The donors of group compound semiconductors tend to use OR group elements. Some oxide semiconductors tend to be electronically conductive because of their chemical ratio, which is hypoxic, and these oxygen vacancies can behave as donors.

That is, n-type semiconductors, which are heated by vacuum, can further strengthen the degree of hypoxia.

2. P-type semiconductors.

P-type semiconductors generally refer to hole-type semiconductors, which are mainly positively charged hole-conductive semiconductors.

Formation. P-type semiconductors are formed by adding trivalent elements (such as boron) to pure silicon crystals to replace the position of silicon atoms in the crystal lattice. In p-type semiconductors, holes are many, and free electrons are few, and they mainly rely on holes to conduct electricity. Due to the amount of positive charge in p-type semiconductors.

It is equal to the amount of negative charge, so p-type semiconductors are electrically neutral. Holes are mainly provided by impurity atoms, and free electrons are formed by thermal excitation.

In terms of materials, there are germanium, silicon, gallium nitride, gallium arsenide, silicon carbide and so on.

From the perspective of original types, there are diodes, transistors (bipolar, FET, IGBT, etc.), thyristors (thyristors), integrated circuits, and so on.

Semiconductor devices are electronic devices that have electrical conductivity between good conductors and insulators, and use the special electrical properties of semiconductor materials to complete specific functions.

It can be used to generate, control, receive, transform, amplify signals, and convert energy. The semiconductor material of semiconductor devices is silicon, germanium, or gallium arsenide, which can be used as rectifiers, oscillators, luminaires, amplifiers, light meters, and other devices.

Common semiconductor materials.

There are silicon, germanium, gallium arsenide.

Wait. Semiconductors also exist in a variety of forms, including solids, liquids, gases, plasma, and more. Semiconductors are materials that conduct electricity at room temperature between conductors and insulators.

Semiconductors are materials that have a controllable electrical conductivity, ranging from insulators to conductors, and affect people's lives.

We usually refer to materials with poor electrical conductivity, such as coal, intraocular crystals, amber, ceramics, etc., as insulators. Metals with good conductivity, such as gold, silver, copper, iron, tin, aluminum, etc., are called conductors. The material between a conductor and an insulator can simply be called a semiconductor.

Semiconductors in integrated circuits, consumer electronics.

Communication systems, photovoltaic power generation, lighting applications, high-power power conversion and other applications, such as diodes.

It is a device made of semiconductors.

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

According to the doping, it can be roughly divided into p-type and n-type; According to doping or not, it can be divided into intrinsic and impurities; According to the material composition, it can be divided into elemental semiconductors and compound semiconductors, and some are amorphous and liquid semiconductors.

This is something I often come across, I hope you are satisfied!