Kinetics of polarized photoluminescence (PL) of the InP
quantum dots with variable number of resident electrons is studied. A
long-lived component of the degree of circular polarisation of the PL is
found to be present for charged quantum dots and absent for neutral ones.
Behaviour of the long-lived polarisation in longitudinal and transverse
magnetic field is studied. Experimental data obtained allowed us to
conclude that the long-lived polarisation is related to spin orientation in
the quantum dots containing odd number of carriers. We found that the
irreversible spin relaxation time in these dots substantially exceeds 1 ns.