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 ZnOH formation along with ZnSe 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.
Bibliographical noteFunding Information:
This work was supported by the Human Resources Development program (No. 20124010203180) of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea government Ministry of Trade, Industry and Energy. Also, this work was supported by the Center for Inorganic Photovoltaic Materials (No. 2012-0001170) grant funded by the Korea government (MEST).
- Buffer layers
- Chemical bath deposition
- Non-toxic complexing agent
- Thin film solar cells