In this research CdTe and CdTe: Cu thin films with different doping ratios (1, 2, 3, 4 and
5) %, were deposited by thermal evaporation technique under vacuum on glass substrates at
room temperature in thickness 450 nm.
The measurements of electrical conductivity (σ), and activation energies (Ea1, Ea2), have
been investigated on (CdTe) thin films as a function of doping ratios, as well as the effect of
the heat treatment at (373, 423, and 473) K° for one hour on these measurements were
calculated and all results are discussed.
The electrical conductivity measurements show all films prepared contain two types of
transport mechanisms, and the electrical conductivity (σ) increases whereas the activation
energy (Ea) would decrease as the increasing (Cu) percentage in the sample except 5%. It is
also noticed that the electrical conductivity (σ) showed a decreasing trend with increasing
annealing temperature, while the activation energies (Ea1, Ea2) showed opposite trend, where
the activation energies increased with annealing temperature. Also the electrical conductivity
values was found increased about 3- 4 orders when pure CdTe films are doped with (3, 4) %
Cu and annealing at 473 K°. |