Preparation and characterization of chemical bath deposited nanocrystalline ZnSe thin films using Na3-citrate and hydrazine hydrate: A comparative study

In this paper, a comparative study reported on the characteristics of Zinc Selenide (ZnSe) thin films prepared by a chemical bath deposition method using the non-toxic tri-sodium citrate (Na3-citrate) and toxic hydrazine hydrate (HH) as complexing agents. Morphological, structural, chemical, and optical properties were investigated using field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and UV-vis spectroscopy. FE-SEM and AFM studies revealed that the ZnSe thin film prepared using Na3-citrate was highly uniform with very low surface roughness (3 nm) compared to those prepared using HH. XRD and XPS studies revealed formation of a cubic ZnSe phase and exhibited insignificant Zn3OH formation along with Zn3Se binding energies for both the films. UV-vis study showed that the band gap energies of ZnSe thin films prepared using HH and Na3-citrate were 3.1 eV and 2.9 eV, respectively. These investigations show that ZnSe thin films could be grown with good optical, structural, chemical, and compositional characteristics without using a toxic HH complexing agent.