A semiconductor diode is a two-terminal electronic component that exhibits highly asymmetric, non-linear current-voltage characteristics governed by the Shockley diode equation. Under forward-bias conditions (anode positive relative to cathode), the applied voltage reduces the internal potential barrier, allowing exponential diffusion current to flow once the threshold knee voltage (~0.7 V for silicon) is exceeded. In reverse bias, the depletion zone widens, restricting current to a minuscule, temperature-dependent reverse saturation current I_s.