The Science of Everything Podcast Episode 92: How Computers Work Part II - Silicon and Transistors
16 snips
Jan 9, 2018 AI Snips
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Transcript
Episode notes
Band Gaps Arise From Lattice Periodicity
- Crystal lattices create band gaps: energy regions with no allowed electron states due to periodic potentials.
- These band gaps critically determine whether a material behaves as a metal, semiconductor, or insulator.
Fermi Level Predicts Conductivity
- A material's Fermi level relative to band gaps determines conductivity: metals have many available states, insulators none, semiconductors a small gap.
- Semiconductors conduct moderately at normal temperatures because their band gap is small enough for some thermal excitation.
Doping Tunes Semiconductor Conductivity
- Dope semiconductors with specific impurities to add electrons (n‑type) or holes (p‑type) and tune conductivity.
- Use n and p doping to increase mobile charge carriers and enable controlled current flow.