Thin films of Zn$_{1-x}$ CdxO with x = 0, 0.1, 0.2, 0.3, 0.4 and 0.5
at.% were deposited by electron-beam evaporation technique. It has
been found that, for as-deposited films, both the transmittance and
electrical resistivity decreased with increasing the Cd content. To improve
the optical and electrical properties of these films, the effect of
annealing temperature and time were taken into consideration for Zn$_{1-x}$
CdxO film with x = 0.2. It was found that, the optical
transmittance and the electrical conductivity were improved significantly
with increasing the time of annealing. At fixed temperature of 300 °C,
the transmittance increased with increasing the time of annealing and
reached its maximum values of 81% in the visible region and 94% in the
NIR region at annealing time of 120 min. The low electrical resistivity of
3.6 × 10−3 Ω cm was achieved at the same conditions. Other
parameters named free carrier concentrations, refractive index, extinction
coefficient, plasma frequency, and relaxation time were studied as a
function of annealing temperature and time for 20% Cd content.