Spin-related micro-photoluminescence in Fe³⁺ doped ZnSe nanoribbons

Spin-related emission properties have important applications in the future information technology; however, they involve microscopic ferromagnetic coupling, antiferromagnetic or ferrimagnetic coupling between transition metal ions and excitons, or d state coupling with phonons is not well understood in these diluted magnetic semiconductors (DMS). Fe³⁺ doped ZnSe nanoribbons, as a DMS example, have been successfully prepared by a thermal evaporation method. Their power-dependent micro-photoluminescence (PL) spectra and temperature-dependent PL spectra of a single ZnSe:Fe nanoribbon have been obtained and demonstrated that alio-valence ion doping diminishes the exciton magnetic polaron (EMP) effect by introducing exceeded charges. The d-d transition emission peaks of Fe³⁺ assigned to the ⁴T₂ (G) → ⁶A₁ (S) transition at 553 nm and ⁴T₁ (G) → ⁶A₁ (S) transition at 630 nm in the ZnSe lattice have been observed. The emission lifetimes and their temperature dependences have been obtained, which reflected different spin-phonon interactions. There exists a sharp decrease of PL lifetime at about 60 K, which hints at a magnetic phase transition. These spin-spin and spin-phonon interaction related PL phenomena are applicable in the future spin-related photonic nanodevices.