Effect of film thickness on structural and optical properties of ZnS:Cu films prepared by vulcanization. (October 2020)

• Record Type: Journal Article
• Authors: Ke, Jinlin; Chen, Shuzhen; Song, Ligang; Zhang, Peng; Cao, Xingzhong; Wang, Baoyi; Zhang, Rengang
• Is Part Of: Superlattices and microstructures. Volume 146(2020)
• Publication Date: 2020-10
• Subjects: ZnS:Cu thin films -- Film thickness -- Vulcanization -- Microscopic defects; Superlattices as materials -- Periodicals; Microstructure -- Periodicals; Semiconductors -- Periodicals; Superréseaux -- Périodiques; Microstructure (Physique) -- Périodiques; Semiconducteurs -- Périodiques; 621.38152
• DOI: 10.1016/j.spmi.2020.106671
• Languages: English
• ISSNs: 0749-6036

Abstract

Abstract: ZnS:Cu thin films were prepared by vulcanizing the sputtered Zn:Cu thin films at 500°С in sulfur vapor. The crystal structure, surface morphology, optical properties and microscopic defects of the films were characterized by XRD, SEM, UV–visible spectrophotometer, Raman spectroscopy and slow positron beam Doppler broadening spectroscopy, respectively. The XRD results showed that the ZnS:Cu thin films without any detectable impurities were a cubic structure, further confirmed by Raman spectra. The grain size of ZnS:Cu films was observed to increase from ~150 nm to ~300 nm with film thickness. Besides, apparent changes in the compactness and stoichiometry of the ZnS:Cu films were found with increasing the film thickness. These ZnS:Cu films exhibited a low transmittance in the visible range, with the band-gap energies of 3.52–3.62eV. Also, the effect of film thickness on microscopic defects of ZnS:Cu films were discussed in detail. Highlights: The properties of various thick ZnS:Cu thin films prepared by vulcanizing the sputtered Zn:Cu films were studied. Cubic structure of the ZnS:Cu thin films was confirmed by XRD in combination with Raman spectra. Positron annihilation spectroscopy were used to characterize the microstructure of ZnS:Cu thin films. Film thickness has an obvious effect on the properties of ZnS:Cu thin films. The great change in grain size was found for Zn:Cu films after and before vulcanization.