2 at.% Ga-doped MgxZn1−xO (x = 0–8%) films have been prepared by sol–gel dip-coating method, and the
effects of three different post annealing ambient: (a) vacuum annealing under air pressure of ∼10
−2
Pa;
(b) annealing in nitrogen atmosphere, and (c) annealing in argon-hydrogen (96%argon + 4%hydrogen)
atmosphere on the electrical and optical properties of the films are investigated. When treated by these
three different post-annealing ambient, both the resisitivity and band gap of the films increase with Mg
doping contents increasing from 0 to 8 at.%. The vacuum annealed films show much lower resistivity
than those treated in nitrogen or argon–hydrogen atmosphere, and the transmittance of the vacuum
annealed films (∼70%) is also lower than those annealed by the other two methods (∼90%) in visible
region. It shows that different post annealing ambient and ion doping could modify the optoelectronic
properties of ZnO film