Investigation of the effect of temperature on growth mechanism of nanocrystalline ZnS thin films

• Published in: Materials letters 2008-11, Vol.62 (28), p.4345-4347
• Main Authors: Sahraei, R., Aval, G. Motedayen, Baghizadeh, A., Lamehi-Rachti, M., Goudarzi, A., Ara, M.H. Majles
• Format: Article
• Language: English
• Subjects: Chemical deposition; Mechanism of ZnS thin film growth; Nanomaterials; Thin films
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2008.07.022

In this paper the temperature effect on the growth mechanism of ZnS thin films prepared in a chemical bath containing zinc acetate, ethylenediamine, and thioacetamide aqueous solutions has been studied in the temperature range between 25 and 75 °C. These ZnS thin films possess a nanocrystalline structure, exhibit quantum size effects due to the small crystal size and produce a blue shift in the optical spectra. This blue shift was attributed to a decrease in crystal size by using X-ray diffraction and scanning electron microscopy. The growth mechanism of the thin films is suggested to proceed by two fundamental steps: in the first step, the ZnS nanocrystallites coalesce into small grains through homogeneous nucleation in the solution phase. In the second step, eventually, these small grains or large-sized clusters diffuse and stick to the surface of the substrate to form the ZnS thin film, in a way called a cluster-by-cluster manner, resulting in particulate thin film.