Formation and Characteristics of PN Junction P-type semiconductors have holes as majority carriers, while n-types have electrons. By doping silicon with p- and n-type impurities on opposite sides, a PN junction forms where these regions meet. Electrons from the N side diffuse to the P side, recombining with holes near the junction to create immobile positive and negative ions in a depletion region devoid of free charge carriers. This region establishes an electric field that creates a barrier potential (0.7V for silicon) preventing most majority carrier movement without external biasing.
Forward Bias: Reducing Depletion Resistance In forward bias mode, connecting positive voltage to P-side reduces the built-in electric field at the depletion zone's boundary. The reduced resistance allows more electrons from N-side and holes from P-side to cross into each other's regions when applied voltage exceeds 0.7V for silicon diodes—facilitating current flow through recombination processes across both sides.
Reverse Bias: Minority Carrier Current Flow Under reverse bias conditions (negative terminal connected to P), majority carriers are repelled away increasing depletion width significantly; however minority charges still traverse due-to internal fields generating minimal currents called Reverse Saturation Currents which remain stable despite rising voltages until breakdown occurs beyond critical thresholds causing sudden conduction surges
'Temperature Effects & Breakdown Voltage' Impact On Diode Behavior. 'Thermal variations double saturation-currents every ten-degree Celsius increment affecting diode-performance inversely proportional temperature-rise exceeding-breakdown-limits triggers-heavy-conduction-minority-carriers crossing-depleted-barrier-region