What defines a semiconductor?

A semiconductor is defined as a material that has electrical conductivity that lies between that of a conductor (like copper or aluminum) and an insulator (like rubber or glass). This unique property allows semiconductors to conduct electricity under certain conditions, which is crucial for their use in electronic devices.

Semiconductors can be modified through the addition of impurities, a process known as doping, which enhances their electrical properties. For instance, silicon, a common semiconductor, can have its conductivity adjusted to make it suitable for various applications, such as diodes and transistors in circuits. This ability to control conductivity is fundamental in electronic technology, making semiconductors essential for creating integrated circuits and microchips.

The other choices do not accurately capture the nature of semiconductors. A material with high electrical conductivity is a conductor, while a material with no electrical conductivity is an insulator. Claiming that a material only conducts electricity at high temperatures does not reflect the general behavior of semiconductors, which can conduct at room temperature with the proper conditions or modifications.