Fluorescence spectra of the layered semiconductor compound MnPS3

Fluorescence measurements on MnPS3 layered semiconductor crystals, in the visible region, below their fundamental absorption thresholds, were carried out at room temperature. The resulting emission spectra show four overlapping structures, which fall in the region of intraion transitions for the Mn2+ 3d5 configuration. The results, deduced from deconvolution of the bands, agree well with those obtained from optical-absorption measurements and furthermore confirm the Mn2+ 3d energy-level distribution derived from the transition-metal weakly interacting model. From the analysis of the excitation spectrum for the MnPS3 fluorescence band centered at 2.23 eV, additional information about the Mn2+ 3d excited-energy-state distribution and a verification of the validity of the above model are obtained.