Electrical charge conductivity behavior of electrodeposited Cu ₂O/ZnO heterojunction thin films on PET flexible substrates by impedance spectroscopy analysis

The bottom-up self-assembly Cu₂O/ZnO heterojunction thin films electrodeposited on indium tin oxide flexible substrate (polyethylene terephthalate, PET) have been investigated by impedance spectroscopy. It is used to study the electric conductivity of the Cu₂O/ZnO heterojunction thin films combined electric modulus and impedance plots. The electric modulus and impedance as a function of the frequency analysis show the distribution of the relaxation times due to the hopping of charge carriers among defects in the Cu₂O/ZnO heterojunction thin films. The values of activation energies derived from the electric modulus and impedance are found to be 0.42 and 0.40 eV, respectively, which is close to the activation energy (0.28 eV) of dc electrical conductivity and activation energy of ac conductivity (0.45-0.14 eV at the range of 100 Hz-1 MHz) in the temperature range over 303-423 K.