Suppression of the Auger recombination due to spin polarization of excess carriers and ${\mathrm{Mn}}^{2+}$ ions in the semimagnetic semiconductor ${\mathrm{Cd}}_{0.95}$${\mathrm{Mn}}_{0.05}$S

The observation of a strong increase in the photoconductivity of ${\mathrm{Cd}}_{0.95}$ ${\mathrm{Mn}}_{0.05}$S under an applied magnetic field is reported. The effect, observed at low temperatures, is explained to arise due to the dramatic suppression of the Auger recombination processes involving the excitation of ${\mathrm{Mn}}^{2+}$ ions ${(}^6$ ${\mathit{A}}_1$ ${\to }^4$ ${\mathit{T}}_{1\left(2\right)\mathrm{}}$ transitions within a 3d shell). The single-ion-assisted Auger recombination, which determines the lifetime of the excess carriers at low magnetic fields, become forbidden for the totally spin-polarized single ions, and at high magnetic field the cluster-assisted Auger recombination dominates.