What Is a Semi Conductor?

A semi conductor is a crystal material that exhibits both conductive and insulating properties. Its ability to conduct electricity can be increased by doping with impurities or gating with electric fields.

Unlike metals, a semiconductor has a partially empty conduction band. This allows electrons to move from the valence band into the conduction band, which can be accomplished through thermal vibration or the application of an electric field.

Conductivity

Conductivity is a property of a material, such as a metal or a solution, that describes the ease with which it conveys heat, electricity, or sound. It depends on the material’s structure and how the atoms are arranged. For example, copper has a higher conductivity than gold, but copper is used more often in electrical applications because it costs less. It is also related to the material’s ability to withstand corrosion.

The electrical conductivity of a material is based on the electrons’ state in the electronic band structure. A highly conductive metal such as copper has a large number of electrons in the conduction semi conductor band, which allows for the easy transfer of electric currents. In contrast, an insulator has more electrons in the valence band, which hampers the flow of electrons.

A measure of a material’s capacity to convey heat or electricity, the conductivity of a semiconductor is defined as the electrical current per unit length of a slab with a given temperature gradient between its two faces. It is the reciprocal of resistance, and it varies with the material’s composition and crystal structure.

Conductivity measurements can be used to detect changes in water quality. For instance, if the amount of dissolved salts increases in a water sample, it will have a greater conductivity than a pure sample. This is why a change in conductivity can be an early warning sign of pollution in water bodies.

The concentration of ions in a water sample also affects its conductivity. Because conductivity is a good indicator of the presence of ions, it can be used to estimate total dissolved solids (TDS) when the composition of the solution is known. However, because TDS can also vary with temperature, the relationship between conductivity and TDS is not exact.

Resistivity

The resistance of a material is the amount it opposes the flow of electric current. It is measured in ohms (O). It is important to know the resistivity of a material when designing electrical circuits and devices. It can help ensure that the voltage required to drive current is adequate and prevent the overheating of components.

Electrical resistance occurs at the molecular level in all materials. It occurs because atoms in metal conductors have free electrons that can move randomly from one atomic shell to another. When a potential difference, also known as voltage, is applied to a conductor, these free electrons can be made to flow along the conductor. This flow is called electric current, and it provides the energy necessary to operate a device or circuit.

Some substances have a lot of resistance to current flow, while others have little or no resistance at all. When a substance has high resistance, it is known as an insulator. Conductors, on the other hand, have low resistance and allow current to pass through them easily.

All electrical devices and circuits have some degree of resistance. However, some have a very small amount and are considered to be very safe for human use. These are called superconductors, and they can carry huge amounts of current without heating or saturating.

A device’s resistance is affected by a number of factors, including its length, semi conductor supplier material, and temperature. For example, the resistance of a wire is proportional to its length and inversely proportional to its cross-sectional area. It can also be reduced by adding more conductors to the circuit or using a different material with less resistance. The resistance of a material can also be adjusted by using electronic components that have a set resistance value, such as resistors.

Temperature

Depending on the temperature of a semiconductor, it can act as an insulator or a conductor. The conductive property of semiconductors is the result of the arrangement of electrons in different energy bands. Electrons in a semiconductor have two distinct energy states: one is a low energy state and the other is a high energy state. The difference in energy between these two states is the band gap. The gap is the boundary between the valence and conduction bands.

When the gap is large, a semiconductor acts like an insulator. But when the gap is small, a semiconductor conducts electric current. The temperature of a semiconductor determines the gap size. The higher the temperature, the larger the gap. This is because the free electrons in the valence band have less thermal energy than the electrons in the conduction band. The free electrons have to gain more energy to break out of the valence band and participate in conduction.

The temperature of a semiconductor is influenced by the presence of impurities and its doping concentration. In intrinsic semiconductors (doped with no foreign atoms), the conductivity increases as the temperature rises. This is because more thermal energy enables more electrons to break out of the valence band into the conduction band. However, in extrinsic semiconductors, the effect of temperature on conductivity is reversed. The doping concentration affects this behavior, with more impurities lowering the conductivity and less impurities increasing it.

Electrical methods such as thermocouples and infrared cameras are often used to measure the temperature of a semiconductor component. These methods have several advantages, including their ability to measure the temperature of a semiconductor at ambient temperature. Moreover, they do not require the component to be powered on. However, they have limitations that make them difficult to use outside the laboratory. In particular, they do not provide an accurate measurement of the maximum junction temperature (Tjmax). Indirect measurements of temperature are also possible using luminescence, a phenomenon resulting from the recombination of electrons and holes.