Band theory: conductors, insulators, semiconductors
Advanced Chemical Bonding · Chemistry
Study notes
Why does silicon conduct better when heated, but copper conducts worse? Step 1: Silicon: small band gap (~1.1 eV). Heat excites electrons across the gap → more carriers → better conduction. Step 2: Copper: bands already overlap; plenty of carriers at all T. Step 3: Heating copper increases atomic vibrations → more electron scattering → resistance rises. Step 4: Opposite T-dependence is the hallmark distinguishing semiconductors from metals!