Self-consistent calculations of carrier distribution and energy bands in InGaAs/InP p-i-n diodes

Abstract

One dimensional semiconductor device equations are solved for the double-heterojunction p-i-n diode using a state variable model. Using this model, Poisson equation and the current density equation are solved simultaneously in a single integration step. The boundary conditions at both the heterojunctions are satisfied for a given device geometry with abrupt junctions. The degeneracy of the semiconductor is considered in the simulations and the depletion width is obtained without the abrupt space-charge approximation. The numerical integration step is varied to ensure charge neutrality across the junctions. The integration is combined with Extended Kalman Filter to ensure consistency with the boundary conditions and among the variables. The electric field, the energy bands, and the carrier distributions obtained are self-consistent. The results obtained for two types of device structures, one grown with an undoped InP buffer layer and one without the buffer layer are discussed.