Semiconductor Equations
Semiconductor Equations - Related Videos
12:36
Semiconductors
0 Views •
2023
Source: Derek Wilson, Asantha Cooray, PhD, Department of Physics & Astronomy, School of Physical Sciences, University of California, Irvine, CA Semiconductors are materials whose ability to conduct an electrical current depends strongly on their temperature and level of impurity. The most common type of semiconductor material is crystalline silicon. Most pure semiconductors are not outstanding conductors; to improve conductivity, a pure semiconductor is often combined or "doped" with an...
01:22
Semiconductors
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2024
There is variation in the electrical conductivity of materials - metals, semiconductors, and insulators that are showcased with the help of the energy band diagrams. Metals such as copper (Cu), zinc (Zn), or lead (Pb) have low resistivity and feature conduction bands that are either not fully occupied or overlap with the valence band, making a bandgap non-existent. This allows electrons in the highest energy levels of the valence band to easily transition to the conduction band upon gaining...
11:14
Comprehensive Characterization of Extended Defects in Semiconductor Materials by a Scanning Electron Microscope
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Cited by 4 •
2016
The optical, electrical, and structural properties of dislocations and of grain boundaries in semiconductor materials can be determined by experiments performed in a scanning electron microscope. Electron microscopy has been used to investigate cathodoluminescence, electron beam induced current, and diffraction of backscattered electrons.
03:10
Chemical Equations
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2020
Chemical equations represent the identities and relative quantities of substances involved in a chemical reaction. The substances undergoing reaction are called reactants, and their formulas are placed on the left side of the equation. The substances generated by the reaction are called products, and their formulas are placed on the right side of the equation. Plus signs (+) separate individual reactant and product formulas, and an arrow (→) separates the reactant and product (left and right)...
02:55
Thermochemical Equations
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2020
For a chemical reaction (the system) carried out at constant pressure – with the only work done caused by expansion or contraction – the enthalpy of reaction (also called the heat of reaction, ΔHrxn) is equal to the heat exchanged with the surroundings (qp). The change in enthalpy is an extensive property, and it depends on the amounts of the reactants participating in the reaction (or the number of moles of reactants). The change in enthalpy is specific to the reaction, and the physical...
FAQs
Carrier statistics describe how many mobile electrons and holes are present, while Poisson’s equation connects their charge density to electrostatic potential and electric fields. This coupling allows the equations to represent how charge distributions modify fields and how those fields, in turn, influence carrier behavior. The interaction is essential for predicting internal device conditions rather than treating carriers and fields independently.
Poisson’s equation relates electrostatic potential to charge density within the material. In a device model, this relationship helps determine electric-field distributions created by carriers and other charge contributions represented in the equations. Its solution supports analysis of structures such as p-n junctions and helps predict features including depletion regions and voltage-dependent internal behavior.
The drift-diffusion equations describe carrier motion resulting from electric fields and spatial variations in carrier concentration. Mobility represents how readily carriers respond during transport, while applied conditions influence the resulting current and charge movement. Combining these effects helps explain current flow through semiconductor structures and supports predictions of voltage-current behavior under different operating conditions.
Continuity equations account for changes in carrier populations by including generation and recombination processes. Generation adds carriers, whereas recombination removes them, so both affect the local balance needed to determine current and charge distributions. Including these terms allows semiconductor equations to represent nonuniform carrier behavior and device response under applied conditions more accurately.
For a p-n junction, the coupled equations relate carrier statistics, charge density, electrostatic potential, and transport. Solving them reveals how internal fields and carrier distributions develop across the junction, including the depletion region. Under applied conditions, the same framework connects these internal changes with voltage-current behavior, making it useful for analyzing diode operation and related structures.
A typical analysis identifies the device structure, carrier quantities, material properties, and applied conditions, then formulates the coupled electrostatic, transport, and continuity relationships. The equations are solved together, often through numerical simulation when the structure or conditions are complex. The resulting potentials, carrier behavior, and currents can then be examined to evaluate device response.
Solutions can provide predictions of voltage-current behavior, depletion-region characteristics, switching performance, and broader device response. Engineers use these results to study diodes, transistors, and other semiconductor structures, compare behavior under applied conditions, and support circuit design. Numerical solutions also help investigate device operation when analytical treatment cannot adequately represent the coupled charge and transport behavior.