Respuesta :

You have to have electrons that are in the materials conduction band. Then you apply a voltage across the material. 
Erudite1
For the electrons in a material to create an electric current THERE MUST BE FLOW OF THE ELECTRONS, CHARGES MUST FLOW CONTINUOUSLY FROM ONE POINT TO ANOTHER.Electric current refers to the continuous flow of electric charges through a material. For an electrons to flow in a material, the material must be a conductor.