Transport solutions for the SCH quantum-well laser diode

The current-voltage relations for the barrier regions in the SCH quantum well laser diode are derived in general terms under the assumption of charge neutrality. The boundary conditions are established at the quantum well SCH region interface by the clamping of the Fermi levels in the quantum well above threshold. It is shown that the current flow is comprised of opposing drift and diffusion flows with drift slightly in excess of diffusion. The recombination current in the SCH region has contributions from both drift and diffusion mechanisms. Expressions are also derived to determine the resistance and capacitance associated with the SCH transport. The appropriate small-signal current versus small-signal Fermi level dependence is specified for application to the small-signal laser response formulation.