Semiconductors

Definition

Semiconductors are materials that have electrical conductivity between that of insulators and conductors, allowing them to control the flow of electrical current. They play a crucial role in the electronic properties of solids, enabling various applications such as transistors, diodes, and integrated circuits. Their unique ability to be modified by doping and changes in temperature makes them essential for developing solid-state materials and understanding the properties of carbon group elements and their compounds.

5 Must Know Facts For Your Next Test

1. Silicon and germanium are the most commonly used semiconductors due to their favorable electronic properties and abundance.
2. Semiconductors can exhibit different conductivity based on temperature; increasing temperature generally increases their conductivity.
3. The ability to control charge carriers in semiconductors allows for the creation of electronic components such as diodes and transistors, which are fundamental in modern electronics.
4. The electrical behavior of semiconductors is influenced by the presence of impurities or dopants, which can create either n-type (negative) or p-type (positive) semiconductors.
5. Carbon group elements, such as silicon and germanium, are pivotal in semiconductor technology due to their four valence electrons, allowing for versatile bonding configurations.

Review Questions

• How does doping affect the electrical properties of semiconductors and what role does it play in their applications?
  • Doping significantly alters the electrical properties of semiconductors by introducing impurities that add free charge carriers. This process creates n-type or p-type semiconductors, enhancing their conductivity and enabling their use in various electronic devices like transistors and diodes. Without doping, intrinsic semiconductors would have very limited conductivity, making it challenging to develop effective electronic components.
• Compare and contrast intrinsic and extrinsic semiconductors, focusing on their structure and functionality.
  • Intrinsic semiconductors are pure materials with no significant impurities, characterized by a relatively low conductivity at low temperatures. In contrast, extrinsic semiconductors are those that have been doped with specific impurities to enhance conductivity. The structure of extrinsic semiconductors allows for the introduction of free charge carriers that facilitate current flow, which is crucial for their functionality in electronic devices.
• Evaluate the impact of temperature on the performance of semiconductors and how this knowledge influences their use in technology.
  • Temperature plays a critical role in the performance of semiconductors by affecting their conductivity. As temperature increases, more charge carriers become available, enhancing conductivity and enabling better performance in devices. This relationship informs engineers when designing electronic components for varying operational environments, ensuring reliable functionality across different temperatures, which is vital for applications ranging from consumer electronics to industrial machinery.

Related terms

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

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

Intrinsic Semiconductor: A pure semiconductor material without any significant dopant atoms present, exhibiting relatively low conductivity at absolute zero temperature.