What happens to the resistance of semiconductors as they are heated?

When semiconductors are heated, their resistance decreases. This behavior is primarily due to the increased thermal energy that excites more electrons in the semiconductor material, allowing them to move freely and contribute to electrical conduction. As the temperature rises, more charge carriers (electrons and holes) are generated, which enhances the material's conductivity and reduces its resistance.

In many semiconductor applications, this property is utilized to create components such as thermistors, which change resistance with temperature changes. This is a fundamental characteristic of semiconductors and is in contrast to metals, where increasing temperature typically leads to greater resistance due to increased lattice vibrations impeding electron flow. Therefore, the correct choice highlights the unique electrical properties of semiconductors that are vital in various electronic devices.