Photoluminescence spectra of the Mn²⁺d-d multiplets transitions of zinc-blende MnTe epitaxial films: Laser and deuterium lamp excitation study

The luminescences of zinc-blende MnTe epitaxial films are respectively excited by a laser and deuterium lamp to study Mn²d -d multiplets transitions. Besides the inclusion of the band gap, all other excited states related to Mn²d -d transitions including⁴T₁ ⁴G,⁴T₂ ⁴G,⁴A₁ ⁴E⁴G,⁴T₂ ⁴D,⁴E⁴D, and²T₂ ²I are observed. The shift and broadening of the⁴T₁ ⁴G and⁴T₂ ⁴G lines with increasing temperature are described by the electron–phonon coupling. Step-like energy and intensity shifts for the⁴A₁ ⁴E⁴G,⁴T₂ ⁴D,⁴E⁴D, and²T₂ ²I transitions occur in the vicinity of the Néel point, which can be ascribed to the different spin-ordering-induced energy relaxation in ground and excited states of Mn²d -d multiplets, and these transitions show temperature independence and weak quenching.