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#barrier height

2 public questions tagged with this topic.

In forward bias, the effective barrier height of a p-n junction is:

**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 forward bias, the applied voltage ( V ) opposes the built-in potential ( V₀ ), reducing the effective barrier height to V₀ - V , allowing more carriers to cross the junction. Substituti

Ref: NCERT > Physics Book > Electronic Devices > p-n Junction, Depletion Region and Diode Characteristics

In a reverse-biased p-n junction, the effective barrier height is:

**Depletion region** also called space-charge region, thickness typically 0.5 μm, contains no mobile carriers, only fixed ions, negative on p-side, positive on n-side, diffusion current due to concentration gradient, drift current due to field, equilibrium when J_drift + J_diff =0, voltage drop mainly across depletion region. In reverse bias, the applied voltage ( V ) adds to the built-in potential ( V₀ ), increasing the effective barrier height to V₀ + V . Substituting values gives V₀ + V, which matches expected behaviour for this semiconductor device configuration, confirming doping, depleti

Ref: NCERT > Physics Book > Electronic Devices > p-n Junction, Depletion Region and Diode Characteristics