Semiconductors

Definition

Semiconductors are materials that have electrical conductivity between that of conductors and insulators, making them essential for electronic devices. Their unique properties allow them to conduct electricity under certain conditions while acting as insulators under others, which is crucial for the function of transistors, diodes, and various types of sensors used in modern technology.

5 Must Know Facts For Your Next Test

1. Semiconductors can be classified into two types: intrinsic (pure) and extrinsic (doped) semiconductors, with the latter having modified electrical properties due to impurities.
2. Common semiconductor materials include silicon and germanium, which are widely used in the electronics industry for their favorable electrical characteristics.
3. The behavior of semiconductors is heavily influenced by temperature; as temperature increases, the number of charge carriers can increase, enhancing conductivity.
4. Semiconductors play a critical role in the development of modern technologies, including solar cells, light-emitting diodes (LEDs), and microprocessors.
5. The invention of the transistor in the 20th century revolutionized electronics by allowing for the miniaturization and enhancement of electronic devices based on semiconductor technology.

Review Questions

• How does the electrical behavior of semiconductors differ from that of conductors and insulators?
  • Semiconductors have a unique position in terms of electrical behavior compared to conductors and insulators. While conductors allow electricity to flow freely due to a high number of free charge carriers, insulators prevent electricity from flowing due to a lack of free charge carriers. Semiconductors, on the other hand, can conduct electricity under certain conditions such as temperature changes or when doped with impurities, allowing for controlled conductivity that is essential in electronic applications.
• Discuss the importance of doping in semiconductors and how it affects their conductivity.
  • Doping is crucial for modifying the electrical properties of semiconductors. By introducing specific impurities into a semiconductor material, such as silicon, we can create n-type (negative) or p-type (positive) semiconductors. N-type semiconductors have extra electrons contributed by donor atoms, while p-type semiconductors have holes created by acceptor atoms. This alteration in charge carrier concentration allows semiconductors to achieve desirable conductivity levels, enabling their use in various electronic devices.
• Evaluate how advancements in semiconductor technology have impacted modern electronic devices and society.
  • Advancements in semiconductor technology have had profound effects on modern electronics and society as a whole. The miniaturization and increased performance of transistors have led to the creation of compact devices like smartphones and laptops. Moreover, improvements in semiconductor materials and fabrication techniques have enabled the development of efficient solar cells and energy-saving LEDs, contributing to sustainability efforts. As a result, these advancements not only drive technological innovation but also play a significant role in economic growth and environmental impact.

Related terms

Conduction Band: The range of energy levels in a solid where electrons can move freely and contribute to electrical conductivity.

Valence Band: The energy band that contains the valence electrons, which are responsible for the bonding between atoms in a material.

Doping:

The process of adding impurities to a semiconductor to change its electrical properties, typically by increasing its conductivity.