What characteristic is essential for materials classified as semiconductors?

Semiconductors are defined by their unique electrical properties, which fall between those of conductors and insulators. The essential characteristic that allows them to function in electronic devices is their intermediate conductivity. This means that semiconductors can conduct electricity under certain conditions, such as when doped with impurities or when subjected to specific temperatures or electric fields.

This property is crucial because it enables semiconductors to be used in various applications, including diodes, transistors, and integrated circuits, where precise control of electrical conductivity is required. The ability to manipulate their conductive properties makes semiconductors versatile and essential for modern electronics.

The other options describe properties that do not align with the fundamental nature of semiconductors. High resistance would classify a material more as an insulator, low conductivity implies a lack of effective charge transport, and the ability to function only under high temperatures does not reflect the standard operational range of most semiconductor materials.