The optical and luminescence properties of Zn1-xGdxO (0≤x≤0.07) quantum dots synthesized via tetraethyl orthosilicate assisted colloidal regime for laser diodes application potential

Abstract

Here, we report about Zn1-xGdxO (0 ≤ x ≤ 0.09) semiconductor quantum dots synthesized via tetraethyl orthosilicate assisted colloidal regime for first time. The X-ray diffraction disclosed that the introduction of Gd ions in Zn sites of ZnO did not affect its hexagonal phase. The transmission electron microscopy divulged that the Gd ions caused an increasing of the particle size of Zn1-xGdxO QDs from 3 nm to 18 nm. The EDAX spectra inspected the stoichiometry and high purity of the synthesized Zn1-xGdxO QDs. The doping of ZnO QDs by Gd ions gives rise to a red shifting of the absorption and emission optical spectra. The doping of ZnO QDs by Gd ions instigates a reduction of the ZnO band gap from 3.3 to 2.8 eV. The doping of ZnO QDs by Gd ions improves the luminescence intensity, reduces the spectral width and suppresses the crystal defects. The quantum yield improved from 31% to 94%. These outstanding behaviors give rise to develop prohibitive superiority laser diode from the nanocrystalline Zn1-xGdxO semiconductor quantum dot.