Investigation on the Structural and Electrical Properties of ZnO Thin Films Co-Doped with Rare Earth Gd and Al Prepared by Co-Sputtering Method

Undoped ZnO, Gd-doped ZnO, and (Al, Gd) co-doped ZnO thin films were synthesized using the co-sputtering technique on a glass substrate. XRD data confirmed all the films are hexagonal structures with dominant (002) diffraction peaks. There are no secondary phases or other peaks detected except for ZnO which proves well incorporation of Gd 3+ and Al 3+ ions into ZnO ions for Gd and (Al, Gd) co-doping ZnO thin films. The EDX analysis shows the composition of Al, Gd, Zn, and O for (Al, Gd) co-doped ZnO thin films considering the successfully doping of Gd and Al into ZnO structure by this deposition method. As compared with undoped ZnO and Gd-doped ZnO, the electrical properties of (Al, Gd) co-doped ZnO showing a good enhancement of carrier concentration (2.34 x 10 26 m -3 ) and electrical conductivity (1.41 x 10 5 Ωm -1 ) whereas the resistivity is low about 7.11 x 10 4 Ωcm.