Optical properties and dynamical behavior of localized and bound excitons in ${\mathrm{Cd}}_{1\mathrm{-}\mathit{x}}$${\mathrm{Mn}}_{\mathit{x}}$Te (x=4%) grown by molecular-beam epitaxy

An epitaxial ${\mathrm{Cd}}_{1\mathrm{-}\mathit{x}}$ ${\mathrm{Mn}}_{\mathit{x}}$Te (x=4%) layer has been grown on a CdTe buffer layer on a GaAs substrate by the molecular-beam-epitaxy method. Comparing the photoluminescence (PL) spectra of ${\mathrm{Cd}}_{1\mathrm{-}\mathit{x}}$ ${\mathrm{Mn}}_{\mathit{x}}$Te with those of CdTe, two peaks in the ${\mathrm{Cd}}_{1\mathrm{-}\mathit{x}}$ ${\mathrm{Mn}}_{\mathit{x}}$Te PL domain were assigned to localized and bound exciton emissions. The results obtained by PL measurements in magnetic fields up to 40 T support this assignment. The observed temporal energy shifts of the localized and bound exciton emissions can be attributed to localized and bound magnetic polaron formations, respectively. Comparing the temporal behavior of bound excitons in magnetic fields with that of localized excitons, a possible process of the bound magnetic polaron formation is discussed.