Effects of Zn amount on the properties of Zn-Cu2O composite films grown for PEC photoelectrodes by using electrochemical deposition

In this study, Zn-Cu 2 O composite films were grown on fluorine-doped tin-oxide (FTO) substrates by using the electrochemical deposition method. Various amounts of Zinc (Zn) were added to grow the Zn-Cu 2 O composite films. We analyzed the morphological, structural, optical energy band gap and photocurrent density properties of the Zn-Cu 2 O composite films by using various measurements such as field-emission scanning electron microscope (FE-SEM), X-ray diffraction (XRD), UV-visible spectrophotometry and potentiostat/galvanostat measurements, respectively. As a result, the highest photocurrent density value of −4.04 mA/cm 2 was obtained for the 30-wt% sample, which had the lowest Cu 2 O (111)/ ZnO (101) XRD peak intensity ratio. The highest photocurrent density value from the 30-wt% sample was approximately 2.35 times higher than that from the non-composite Cu 2 O film (0-wt% sample). From this study, we found that adding Zn could improve the photocurrent values of Zn-Cu 2 O composite films.