Study of the effect of Fe doping on the structural and optical properties of CdSe films obtained using the electrochemical deposition method

Using the electrochemical deposition method, Fe-doped CdSe films were obtained from electrolyte solutions. By varying an applied potential difference, films with different phase compositions were obtained: CdSe, FeSe/CdSe. At the same time, increasing the applied potential difference from 1.0 to 1.25–1.5 V leads not only to the formation of a new FeSe phase characteristic of a solid substitution solution, but also to a significant increase in the crystallinity degree and a decrease in dislocation density. According to elemental analysis, it was found that increasing the applied potential difference to 1.25–1.5 V leads to an increase in iron content in the structure by 4–5 times. Analysis of the morphological features of the synthesized films showed that the formation of the FeSe phase leads to an increase in grain sizes, as well as a roughness degree. According to the analysis of the optical characteristics of the synthesized films, the formation of the FeSe phase and the subsequent increase in its contribution leads to an increase in band gap from 1.69 to 1.93–1.98 eV, as well as a decrease in refractive index and reflection losses. The results obtained from evaluating the applicability of the synthesized films as a base for photocatalysts showed that films with double phases exhibit a high degree of photocatalytic degradation of an organic dye.