Semiconductor Band Structure — Conduction, Valence & Doping

⚡ Semiconductor Bands

In a semiconductor, electrons occupy a valence band and a conduction band is separated by a bandgap E_g. Doping shifts the Fermi level and dramatically changes carrier concentrations.

🔩 Material

🎛 Doping

Dopant concentration N_d (cm⁻³ log) 14 Temperature T (K) 300

🔭 View

📐 Properties

Bandgap E_g

1.12 eV

Fermi E_F

mid-gap

n (cm⁻³)

1.0×10¹⁰

p (cm⁻³)

1.0×10¹⁰

ℹ️ Physics

Intrinsic: E_F ≈ midgap; n = p = n_i = √(N_c·N_v)·exp(−E_g/2kT).

n-type (donor): E_F rises toward conduction band; n ≈ N_d.

p-type (acceptor): E_F falls toward valence band; p ≈ N_a.

Mass–action law: n · p = n_i² always holds at equilibrium.