Semiconductors

Definition

Semiconductors are materials with electrical conductivity between that of conductors and insulators, allowing them to control electrical current. They are essential in the development of electronic devices as their properties can be modified by adding impurities, a process known as doping. This ability to manipulate conductivity is crucial for the functioning of devices like diodes and transistors, which play significant roles in modern technology.

5 Must Know Facts For Your Next Test

1. Semiconductors have a unique property called the band gap, which allows them to conduct electricity under certain conditions while acting as insulators under others.
2. Common semiconductor materials include silicon and germanium, which are widely used in the manufacturing of electronic devices.
3. Temperature can significantly affect the conductivity of semiconductors; for example, increasing temperature typically increases their conductivity.
4. Semiconductors are fundamental to the operation of diodes, transistors, and integrated circuits, making them vital for computers and communication technologies.
5. The discovery of semiconductors in the 20th century revolutionized electronics and paved the way for modern computing and telecommunications.

Review Questions

• How do semiconductors differ from conductors and insulators in terms of electrical conductivity?
  • Semiconductors have a level of electrical conductivity that falls between conductors and insulators. Conductors, such as metals, allow electric current to flow easily due to their free electrons. In contrast, insulators resist electric current, lacking free charge carriers. Semiconductors, on the other hand, can conduct electricity under certain conditions by controlling factors like temperature and doping, making them highly versatile materials in electronics.
• Discuss the role of doping in semiconductors and how it influences their electrical properties.
  • Doping is a critical process that involves adding impurities to a semiconductor to enhance its conductivity. By introducing elements with different numbers of valence electrons, such as phosphorus or boron into silicon, the number of charge carriers can be increased or decreased. This manipulation results in either n-type (negative) or p-type (positive) semiconductors, which are essential for creating junctions needed in diodes and transistors, ultimately enabling advanced electronic functionalities.
• Evaluate the impact of temperature on semiconductor behavior and its implications for electronic device performance.
  • Temperature plays a significant role in semiconductor behavior as it affects the movement of charge carriers. At higher temperatures, more electrons gain enough energy to jump across the band gap from the valence band to the conduction band, increasing conductivity. This temperature dependence is crucial for device performance; for instance, temperature fluctuations can lead to changes in transistor switching speeds or diode thresholds. Understanding this relationship helps engineers design reliable electronics that can operate efficiently across varying thermal conditions.

Related terms

Doping: The process of adding impurities to a semiconductor to change its electrical properties, enhancing its conductivity.

Band Gap: The energy difference between the valence band and the conduction band in a semiconductor, determining its electrical conductivity.

Transistor: A semiconductor device used to amplify or switch electronic signals, forming the building blocks of modern electronic circuits.