As semiconductors are heated, their resistance ___

• A. Increases
• B. Decreases
• C. Remains constant
• D. Fluctuates

Answer: (B)

As semiconductors are heated, their resistance decreases. This behavior is largely due to the intrinsic properties of semiconductor materials. At higher temperatures, more charge carriers (electrons and holes) are generated within the semiconductor. The increased thermal energy facilitates the excitation of electrons from the valence band to the conduction band, where they can move freely and conduct electricity.

Consequently, as the number of available charge carriers rises with temperature, the overall resistance of the semiconductor material decreases. This is fundamentally different from metals, where resistance typically increases with temperature due to increased lattice vibrations that impede the flow of charge carriers. Understanding this principle is crucial in applications involving semiconductors, such as in temperature sensors and various electronic devices.