Structural and optical properties of ZnS thin films deposited by RF magnetron sputtering

Dong Hyun Hwang,Kwun Nam Hui,Jung Hoon Ahn,Young Guk Son,Kwan San Hui

doi:10.1186/1556-276x-7-26

Dong Hyun Hwang, Kwun Nam Hui + Show 3 more

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https://doi.org/10.1186/1556-276x-7-26

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Abstract

Zinc sulfide [ZnS] thin films were deposited on glass substrates using radio frequency magnetron sputtering. The substrate temperature was varied in the range of 100°C to 400°C. The structural and optical properties of ZnS thin films were characterized with X-ray diffraction [XRD], field emission scanning electron microscopy [FESEM], energy dispersive analysis of X-rays and UV-visible transmission spectra. The XRD analyses indicate that ZnS films have zinc blende structures with (111) preferential orientation, whereas the diffraction patterns sharpen with the increase in substrate temperatures. The FESEM data also reveal that the films have nano-size grains with a grain size of approximately 69 nm. The films grown at 350°C exhibit a relatively high transmittance of 80% in the visible region, with an energy band gap of 3.79 eV. These results show that ZnS films are suitable for use as the buffer layer of the Cu(In, Ga)Se2 solar cells.

Highlights

Cu(In, Ga)Se2 [CIGS] solar cells are fabricated using a cadmium sulfide [CdS] buffer layer in order to protect the junction region from sputtering damage during subsequent n-type zinc oxide deposition and to modify the surface of p-type CIGS absorber [1]
As the substrate temperature increased to 350° C, the intensity of the peaks corresponding to the cubic phase increased drastically
ZnS thin films have been successfully grown on glass substrates using RF magnetron sputtering at various substrate temperatures ranging from 100°C to 400°C

Summary

Introduction

Cu(In, Ga)Se2 [CIGS] solar cells are fabricated using a cadmium sulfide [CdS] buffer layer in order to protect the junction region from sputtering damage during subsequent n-type zinc oxide deposition and to modify the surface of p-type CIGS absorber [1]. The chemical bath deposition [CBD] technique, which is known as solution growth or chemical deposition, has emerged as a rather efficient method for the deposition of metal chalcogenide thin films. This method is attractive largely because the technique possesses many advantages over other thin film deposition methods, such as low cost, low deposition temperature, and easy coating of large surfaces, making it appropriate for large area industrial applications. The CdS layer fabricated by CBD causes serious environmental problems due to the large

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