Visible-Light Electroluminescence In Mn-Doped Gaas Light-Emitting Diodes

We observed visible-light electroluminescence (EL) due to d-d transitions in light-emitting diodes with Mn-doped GaAs layers (here, referred to as GaAs: Mn). Besides the band-gap emission of GaAs, the EL spectra show two peaks at 1.89 eV and 2.16 eV, which are exactly the same as (4)A(2)(F-4) -> T-4(1)((4)G) and T-4(1)((4)G) -> (6)A(1)(S-6) transitions of Mn atoms doped in ZnS. The temperature dependence and the current-density dependence are consistent with the characteristics of d-d transitions. We explain the observed EL spectra by the p-d hybridized orbitals of the Mn d electrons in GaAs. (C) 2014 AIP Publishing LLC.