Properties of Semiconductor
Some important properties of a Semiconductor are:
- Energy Gap: Semiconductors have a band gap, an energy range positioned between the valence band (with tightly bound electrons) and the conduction band (permitting electron movement), influencing their conductive or insulating nature.
- Dopant Introduction: Controlled introduction of impurities (doping) into semiconductors intentionally alters their electrical characteristics, generating excess charge carriers (N-type) or “holes” (P-type) for conductivity control.
- Temperature Responsiveness: Semiconductors’ conductivity varies with temperature, making them suitable for applications like thermistors and temperature sensors.
- Light Sensitivity: Certain semiconductors become more conductive upon light exposure, proving valuable in photodetectors and solar cells.
- Mechanical Influence: Semiconductors’ resistance can change with mechanical stress (piezo-resistivity), applied in strain gauges and pressure sensors.
- Heat Conductance: With intermediate thermal conductivity, semiconductors manage controlled heat dissipation, crucial for integrated circuits.
- Dielectric Qualities: Semiconductors can act as insulating dielectrics under specific circumstances, contributing to capacitors and energy storage mechanisms.
- Electroluminescence: When subjected to voltage, specific semiconductors emit light, essential in LEDs and displays.
- Quantum Aspects: On the nanoscale, semiconductors reveal quantum effects exploited in quantum dots and quantum well structures for advanced uses.
- Hall Effect: Semiconductors exhibit the Hall effect, where an electric field perpendicular to the current generates measurable voltage, applicable in Hall sensors and current measurement.
- Carrier Mobility: The movement ability of charge carriers (electrons and holes) within semiconductors is determined by carrier mobility, influencing device efficiency and speed.
- Resistivity (ρ): The resistivity decreases with the increase of temperature because of the increase in number of the mobile charge carriers and thus making the temperature coefficient negative.
- Conductivity (σ): The semiconductors act as insulators as zero kelvin but when the temperature increases they start working as the conductors.
- Carrier Concentration (n or p): In semiconductors, the carrier concentration refers to the number of charge carriers (electrons or holes) per unit volume. It’s given by the formula:
n = Nc * exp(Ec - Ef) / k * T
Where,
- n is the carrier concentration
- Nc is the effective state density
- Ec is level of energy of conduction band
- Ef is the Fermi energy level
- k is Boltzmann’s constant
- T is the temperature in Kelvin
Why Does the Resistivity of Semiconductors Go Down with Temperature?
The resistivity of the Semiconductor will decrease with the rise of temperature because the higher temperature will provide the more energy to the electron.The increase of the energy will make electron to jump from Valence band to the conduction band.
Semiconductors
A Semiconductor is a kind of material that performs conductivity between conductors and insulators and has a conductivity value that lies between the conductor and an insulator.
In this article, we will be going through semiconductors, first, we will start our article with the introduction of the semiconductor, then we will go through holes and electrons with band gap theory, and after that we will go through properties and types of semiconductors, At last, we will conclude our article with solved examples, applications and advantages with some FAQs.
Table of Content
- Holes and Electrons
- Direct and Indirect Band Gap Semiconductors
- Properties of Semiconductor
- Types of Semiconductor
- Intrinsic Vs Extrinsic Semiconductors
- Applications of Semiconductor
- Advantages of Semiconductor
- Disadvantages of Semiconductor
- Examples of Semiconductor
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