Fabrication Of ZnMgO Alloy By Pulsed Laser Deposition

Zinc oxide (ZnO) is aⅡ-Ⅵgroup direct wide band gap semiconductor of 3.37 eV at room temperature, with a high exciton binding energy (60 meV), which ensure the high effective exciton and UV emission at room temperature. In order to improve the efficiency of emission and modulate the band-gap, ZnO is often made into alloy material with MgO which has band gap of 7.7 eV. Adjusting the content of Mg in the alloy can change the band-gap of alloy and the optical property of the alloy materials.In this paper, ZnO thin films were grown on the MgO substrate by pulsed laser deposition. The samples were rapidly annealed at different temperatures in order to get the alloy Zn1-xMgxO with different Mg content. The samples were characterized by X-ray diffraction (XRD), photoluminescence (PL), Raman spectra and absorption spectra.The results of XRD for the samples annealed at different temperature indicated that the sample annealed at 700°C has better crystal quality, the sample annealed at 800°C has a better orientation; Blue shifts were observed for the UV peak, 1LO phonon and the absorption edge of PL spectra, Raman spectra and the absorption, respectively, which indicate that we have got the Zn1-xMgxO alloy with different Mg content through annealing at different temperatures. The sample annealing at 900°C had too many defects, and we have come to the conclusion that the annealing temperature of ZnMgO alloy should not be too high. Calculating UV peak of the PL spectra, we obtained four samples with Mg content varied from 0 to 0.116 in a monotony change, to accomplish the purpose that the alloy Zn1-xMgxO of different Mg content, and put forward a preparation method of Zn1-xMgxO alloy, which can be easier getting the Zn1-xMgxO alloy of different components, while avoiding mismatch of the alloy thin film and substrate lattice, as well as elements into the alloy substrate.