PN Junction Diode

← EDC

Built-in potential, depletion region, junction capacitance, and the Shockley diode equation. Built on the transport fundamentals.

Material

Parameters

N_A — p-side doping (cm⁻³)

N_D — n-side doping (cm⁻³)

V_applied (V) — + = forward

Temperature (K)

Use scientific notation for doping (e.g. 5e16). E_f splits across the junction under bias.

E_c E_v E_vac E_i E_f

Depletion Approximation — Visualised

Charge density ρ(x) on the left, electric field E(x) on the right. The area under the E-field triangle is the potential drop across the depletion region: ∫E·dx = V_bi − V_applied.

Sweep: Speed idle

V_bi vs Temperature (at current N_A, N_D)

W, E_max vs V_bias (at current T)

✍ Derivation — click to expand ▶