The Evolution of the Theory for the Voltage-Current Characteristic of P-N Junctions

The rectifying action in semiconductor p-n junctions is controlled essentially by the equilibrium densities, diffusion constants, and recombination times of minority carriers. The low-level behavior of germanium junctions at room temperature is adequately described by a theory which is based on the rate of diffusion and recombination of minority carriers on either side of the barrier region. It is necessary to include the effects of carrier recombination and generation in the barrier region to explain the low-level behavior of silicon. At high current densities, the junctions depart from the ideal low-level rectifier law because of effects associated with majority carrier modulation. As a consequence of recombination current to the barrier region at low levels and conductivity modulation effects at high levels, the simple I8(exp qV/kT-1) behavior is rarely observed in silicon junctions at room temperature.