Practice question

**Diode characteristics** forward bias reduces barrier, width of depletion region decreases, resistance low ~10-100 Ω, current primarily due to majority diffusion, exponential I = I_s(e^{eV/kT}-1), reverse bias widens depletion region, resistance high ~MΩ, dominant current drift due to minority carriers, reverse saturation current small μA-nA, typically 10⁻⁶ A, increases sharply at breakdown Zener/avalanche. In reverse bias, the applied voltage increases the barrier height and electric field, widening the depletion region as more immobile charges are exposed due to reduced carrier diffusion. Substituting values gives Increases, which matches expected behaviour for this semiconductor device configuration, confirming doping, depletion and rectifier principles.