Semiconductor Electronics: Materials, Devices and Simple Circuits — Chapter Summary

Metals have very low resistivity

Metals have very low resistivity in the range 10^-2 to 10^-8 Ω m, semiconductors have intermediate resistivity in the range 10^-5 to 10^6 Ω m, and ins

Metals have overlapping or partially filled

Metals have overlapping or partially filled bands with Eg ≈ 0, insulators have a large band gap Eg > 3 eV, and semiconductors have a small band gap Eg

In a pure semiconductor

In a pure semiconductor, the number of free electrons equals the number of holes, so n_e = n_h = n_i. A hole is a vacancy with effective positive char

When a valence electron leaves its

When a valence electron leaves its bond, it creates a vacancy called a hole. Electron motion gives electron current I_e and hole motion gives hole cur

Adding a small amount of impurity

Adding a small amount of impurity changes the conductivity greatly. Doping a tetravalent semiconductor like Si or Ge with pentavalent impurities such