Concept
Version 8
Created by Boundless
Conductors
Conductors, Semiconductors and Insulators
On the left, a conductor (described as a metal here) has its empty bands and filled bands overlapping, allowing excited electrons to flow through the empty band with little push (voltage). Semiconductors and insulators have a greater and greater energetic difference between the valence band and the conduction bands, requiring a larger applied voltage in order for electrons to flow.
Source
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"File:Isolator-metal.svg - Wikipedia, the free encyclopedia."
http://en.wikipedia.org/w/index.php?title=File:Isolator-metal.svg&page=1
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