What are the carrier transport mechanisms in semiconductor materials

What are the carrier transport mechanisms in semiconductor materials?

Semiconductor materials are a class of electronic materials with semiconductor properties that can be used to fabricate semiconductor devices and integrated electricity. Semiconductor materials are a class of electronic materials with semiconductor properties that can be used to fabricate semiconductor devices and integrated electricity. It is these properties of semiconductor materials that are used to create functionally diverse semiconductor devices. Semiconductor materials are the foundation of the semiconductor industry, and its development has a great impact on the development of semiconductor technology.

Classification of semiconductor materials Semiconductor materials can be roughly divided into the following categories according to their chemical composition and internal structure.

1.Compound semiconductors are semiconductor materials composed of two or more elements. There are many kinds of it, the important ones are gallium arsenide, indium phosphide, indium antimonide, silicon carbide, cadmium sulfide and gallium arsenide silicon. Among them, gallium arsenide is an important material for the manufacture of microwave devices and integrated electronics. Silicon carbide has a wide range of applications in the field of aerospace technology due to its strong radiation resistance, high temperature resistance and good chemical stability. 3. Amorphous semiconductor material Glass used as semiconductor is a kind of amorphous amorphous semiconductor material, which is divided into oxide glass and non-oxide glass. Such materials have good switching and memory properties and strong radiation resistance, and are mainly used to manufacture threshold switches, memory switches and solid-state display devices. 2. Elemental semiconductors are germanium, silicon, selenium, boron, tellurium, antimony, etc. In the 1950s, germanium dominated semiconductors, but germanium semiconductor devices had poor high temperature resistance and radiation resistance, and were gradually replaced by silicon materials in the late 1960s. Semiconductor devices made of silicon have good high temperature resistance and radiation resistance, and are especially suitable for making high-power devices. Therefore, silicon has become the most widely used enhancer material, and most of the current integrated circuits are made of silicon materials. 3. Organic Inductor Materials There are dozens of known organic semiconductor materials, including naphthalene, anthracene, polyacrylonitrile, phthalocyanine and some aromatic compounds, which have not yet been used. The characteristic parameters of semiconductor materials are very important for material applications. Because different characteristics determine different uses.

Semiconductor Material Properties

The conductivity of semiconductor materials is extremely sensitive to certain trace impurities. Semiconductor materials with high purity are called intrinsic semiconductors, which have high resistivity at room temperature and are poor conductors of electricity. After appropriate impurities are doped into high-purity semiconductor materials, the resistivity of the material is greatly reduced because the impurity atoms provide conductive carriers. Such doped semiconductors are often referred to as impurity semiconductors. Impurity semiconductors that conduct electricity by conduction band electrons are called N-type semiconductors, and those that conduct electricity by valence band holes are called P-type semiconductors. When contacting between different types of semiconductors (forming a PN junction) or when a semiconductor is in contact with a metal, diffusion occurs due to the difference in electron (or hole) concentration, forming a potential barrier at the contact, so this type of contact has unidirectional conductivity. Using the unidirectional conductivity of the PN junction, semiconductor devices with different functions, such as diodes, triodes, and thyristors, can be made. In addition, the conductivity of semiconductor materials is very sensitive to changes in external conditions (such as heat, light, electricity, magnetism, etc.), according to which various sensitive components can be fabricated for information conversion. The characteristic parameters of semiconductor materials are band gap, resistivity, carrier mobility, non-equilibrium carrier lifetime and dislocation density. The band gap is determined by the electronic state and atomic configuration of the semiconductor, and reflects the energy required to excite the valence electrons from the bound state to the free state in the atoms that make up the material. Resistivity and carrier mobility reflect the electrical conductivity of materials.