Type II and mixed type I-II radiative recombinations in AlInAs-InP heterostructures

Spatially indirect radiative recombination processes (type II) are analyzed in InAlAs-InP heterostructures by means of a self-consistent solver for Poisson and Schrodinger equations. The cases of heterostructures at equilibrium (under darkness) and under illumination are specifically considered. Special attention is paid to the interface transition energy variation as a function of the photocreated carrier density and to the exact composition of the interface. This study is supported by photoluminescence experiments carried on InAlAs-InP heterostructures fabricated under different growth conditions. It is shown that the type II recombination energy is very sensitive to the exact composition of the interface:a 3 Angstrom thick interface InAs layer is sufficient to shift the type II transition towards lower energies. (C) 1999 American Institute of Physics. [S0021-8979(99)06804-8].