Week 5: Who conducts? Electrons, holes and the energy window

Who conducts? Electrons, holes and the energy window (Datta Sec. 6.5–6.6, Figs. 6.1–6.3)

Each dot is a state (2D channel, 1 dot ≈ a fixed number of states per cm²). Blue = filled, grey ring = empty, red ring = empty state in a downward band (a “hole”). Only states inside the yellow window flicker: that is where the contacts can still add or remove electrons, and where conduction happens.

Material:

Electrochemical potential μ₀ Temperature T

Electrons in upward band n–

Holes in downward band p–

Window average of N(E) (Sec. 6.5)–

Ballistic G_B per µm width–