What characterizes a semiconductor material?

A semiconductor material is characterized by having four valence electrons. This property is essential in defining how semiconductor materials behave electrically. Silicon and germanium, the most common semiconductor materials, possess four electrons in their outer shell. This configuration allows them to form covalent bonds with other atoms, creating a stable crystal structure.

The four valence electrons enable semiconductors to conduct electricity under certain conditions, specifically when energy is added, such as through thermal excitation or doping with other elements. This is crucial in semiconductor physics, where materials exhibit behavior that can range from insulative to conductive based on the presence of impurities or external energy sources.

The other options do not accurately describe the valence electron configuration of semiconductors, which is why they do not characterize these materials correctly.