Semiconductors

Definition

Semiconductors are materials that have electrical conductivity between that of conductors and insulators. They can conduct electricity under certain conditions, making them crucial for modern electronic devices. The unique properties of semiconductors arise from their energy band structure, which can be manipulated through doping and temperature changes, leading to applications in transistors, diodes, and integrated circuits.

5 Must Know Facts For Your Next Test

1. Semiconductors can be intrinsic, with pure materials, or extrinsic, where impurities are added to alter electrical properties.
2. Silicon is the most widely used semiconductor material in electronics due to its favorable properties and abundance.
3. Temperature changes can significantly affect a semiconductor's conductivity; increasing temperature typically increases the number of charge carriers.
4. Semiconductors have a critical role in enabling the miniaturization of electronic components, paving the way for modern computing technology.
5. The behavior of semiconductors is explained using the free electron model and band theory, helping to understand how electrons move within these materials.

Review Questions

• How does doping affect the electrical properties of semiconductors, and why is this process important for electronic devices?
  • Doping alters the electrical properties of semiconductors by introducing impurities that provide additional charge carriers. For instance, adding phosphorus to silicon creates n-type semiconductors with extra electrons, while adding boron creates p-type semiconductors with holes. This manipulation is crucial for creating components like transistors and diodes, allowing for controlled conductivity essential for modern electronics.
• Discuss the significance of the band gap in determining the behavior of semiconductors in electronic applications.
  • The band gap is a key factor in a semiconductor's ability to conduct electricity. It represents the energy required for an electron to move from the valence band to the conduction band. Semiconductors with smaller band gaps can operate at lower temperatures and are more sensitive to light, making them suitable for devices like photodetectors and solar cells. Understanding band gaps allows engineers to design materials with specific electronic properties tailored for various applications.
• Evaluate how advancements in semiconductor technology have influenced modern society and the economy over recent decades.
  • Advancements in semiconductor technology have revolutionized modern society by enabling the development of powerful and compact electronic devices, such as smartphones and computers. The continuous miniaturization of components has led to faster processing speeds and greater energy efficiency. These innovations have not only transformed communication and information sharing but have also driven economic growth by creating new industries and jobs. The global economy heavily relies on semiconductor manufacturing, making it a critical sector influencing technological progress and societal change.

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, which determines its electrical conductivity.

P-N Junction: A semiconductor interface formed by joining p-type and n-type materials, essential for the functioning of diodes and transistors.