The Preparation and Optical Properties of Ni(II) and Mn(II) Doped in ZnTe Nanobelt/Nanorod by Using Chemical Vapor Deposition.

Abstract

The doping techniques are often used to modify the properties of semiconductors. Transition metal ion doping in semiconductor can lead to dilute magnetic semiconductors (DMSs), which may initiate some novel properties related to spins. In contrast to the wide band semiconductor ZnO, ZnSe and CdS crystal the transition metal (TM) ion aggregate can be the origin of the ferromagnetic behaviors, which influence their optical properties mainly through the exciton-spin interactions due to their high exciton binding energy. For narrow band semiconductor, the carrier-spin coupling is the main cause of magnetism as observed in ZnTe. The ZnTe nanobelt for DMS with the TM ions such as Ni(II) and Mn(II) doping mainly induce the excess carrier effect in the lattice after photo-excitation, whose optical properties are also strongly depended on the fabrication method structure and morphology. Photo-excited carriers and electron-phonon interaction (but less excitons) are responsible for their large redshifts in ZnTe nanostructures. The strong interaction between the doped magnetic ion spins and holes, electron-phonon coupling, p-d hybridization as well as local electron correlation in TM ions determined their optical properties. TM ions incorporation in ZnTe lattice has suppressed the broad defect emission band far from the bandedge and broadened the electron correlations and electron hole plasma band near bandedge when excited by the rising excitation powers. We also identified that the polarized PL of Ni(II) and Mn(II) doped samples to calculate the strain dependence of band splitting near valance band.