Spatially indirect radiative recombination processes (type II) are analyzed
in InAlAs-InP heterostructures by means of a self-consistent solver for Po
isson and Schrodinger equations. The cases of heterostructures at equilibri
um (under darkness) and under illumination are specifically considered. Spe
cial attention is paid to the interface transition energy variation as a fu
nction of the photocreated carrier density and to the exact composition of
the interface. This study is supported by photoluminescence experiments car
ried on InAlAs-InP heterostructures fabricated under different growth condi
tions. 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].