  The effect of a lateral electric current on the photoluminescence H-band of
an AlGaAs/GaAs heterostructure is investigated. The photoluminescence intensity
and optical orientation of electrons contributing to the H-band are studied by
means of continuous wave and time-resolved photoluminescence spectroscopy and
time-resolved Kerr rotation. It is shown that the H-band is due to
recombination of the heavy holes localized at the heterointerface with
photoexcited electrons attracted to the heterointerface from the GaAs layer.
Two lines with significantly different decay times constitute the H-band: a
short-lived high-energy one and a long-lived low-energy one. The high-energy
line originates from recombination of electrons freely moving along the
structure plane, while the low-energy one is due to recombination of
donor-bound electrons near the interface. Application of the lateral electric
field of ~ 100-200 V/cm results in a quenching of both lines. This quenching is
due to a decrease of electron concentration near the heterointerface as a
result of a photocurrent-induced heating of electrons in the GaAs layer. On the
contrary, electrons near the heterointerface are effectively cooled, so the
donors near the interface are not completely empty up to ~ 100 V/cm, which is
in stark contrast with the case of bulk materials. The optical spin
polarization of the donor-bound electrons near the heterointerface weakly
depends on the electric field. Their polarization kinetics is determined by the
spin dephasing in the hyperfine fields of the lattice nuclei. The long spin
memory time (> 40 ns) can be associated with suppression of the
Bir-Aronov-Pikus mechanism of spin relaxation for electrons.
