Semiconductor Conduction
So in a ground state, which is like what you study in chemistry, a semiconductor has all it'd valence electrons in the valence band, this is true of all materials. However, there's another band called the conduction band, where the electrons are far enough away from the atom that they can be moved from the atom and thus conduct electricity.

In conductors, these bands overlap, and it always conducts. In semiconductors, these bands are close, but there's a slight gap between them, so you have an insulator, but when you add energy, the electrons move up and it becomes a conductor. It can be in the form of heat, light, electricity, etc.

To answer your question, sort of, there's a finite energy that needs to be added to allow conduction,