Preheated substrate effects on the structural and optical properties of chemically prepared ZnS thin films

International Conference on Materials Science and Technology 2012

Deepa, K.^1,2 ; Preetha, K.C.^3 ; Dhanya, A.C.^1 ; Remadevi, T.L.^2

School of Pure and Applied Physics, Kannur University, Kerala

670327, India^1

Pazhassi Raja NSS College, Mattannur, Kerala

670702, India^2

Sree Narayana College, Thottada, Kannur, India^3

关键词: Chemical bath deposition technique;    Luminescence intensity;    Morphological analysis;    Powder X ray diffraction;    Room temperature photoluminescence spectra;    Structural and optical properties;    UV-vis-NIR spectroscopy;    Wurtzite structure;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/73/1/012010/pdf
DOI  :  10.1088/1757-899X/73/1/012010

来源: IOP

【 摘 要 】

Nanocrystalline zinc sulphide thin films were prepared by an improved chemical bath deposition technique in which glass substrates were thermally treated prior to the deposition process. The microscopic glass slide was heated to 200°C before mounting into the chemical bath. The films prepared with and without preheating the substrate were characterized using various techniques and their properties compared. Structural analysis of the films was done using powder X-ray diffraction technique. Films deposited without preheating were amorphous whereas preheating the substrate resulted in the deposition of highly crystalline film with wurtzite structure having an intense (100) orientation. Morphological analysis using scanning electron microscope revealed the densification of the films deposited on preheated substrate indicating that the nucleation rate was higher in this case as compared to films deposited without preheating. Gravimetric analysis of the films confirmed that preheating results in the deposition of thicker films. The optical analysis of the samples was done using UV-Vis-NIR spectroscopy. All the films had a very low absorbance in the visible region. A red-shift in absorption edge was observed on preheating the substrate which indicates a decrease in band gap. However the transmittance in the visible region decreased on preheating the substrate. Room temperature photoluminescence spectra exhibited UV and violet emission for both the samples. The luminescence intensity was found to increase on preheating.