Improved Optical Transmittance and Crystal Characteristics of ZnS:TbOF Thin Film on Bi₄Ti₃O₁₂/Indium Tin Oxide/Glass Substrate by Using a SiO₂ Buffer Layer

Abstract

Bi4Ti3O12 thin films are deposited on indium tin oxide (ITO)/glass substrates using RF magnetron sputtering technology and are annealed at 675 °C in a rapid thermal annealing furnace in an oxygen atmosphere. The resulting films have high optical transmittances and good crystalline characteristics. ZnS:TbOF films are then deposited on the Bi4Ti3O12 films, causing the originally highly transparent specimens to blacken and to resemble a glass surface coated with carbon powder. The optical transmittance of the specimen is less than 15% under the visible wavelength range, and neither a crystalline phase nor a distinct ZnS grain structure is evident in X-ray diffractometer (XRD) and scanning electronic microscope (SEM). Secondary ion mass spectrometer (SIMS) analysis reveals the occurrence of interdiffusion between the ZnS and Bi4Ti3O12 layers. This suggests that one or more unknown chemical reactions take place among the elements Bi, S, and O at the interface during the deposition of ZnS:TbOF film on a Bi4Ti3O12/ITO/glass substrate. These reactions cause the visible transmittance of the specimens to deteriorate dramatically. To prevent interdiffusion, a silicon dioxide (SiO2) buffer layer 100 nm thick was grown on the Bi4Ti3O12/ITO/glass substrate using plasma-enhanced chemical vapor deposition (PECVD), then the ZnS:TbOF film was grown on the SiO2 buffer layer. The transmittance of the resulting specimen is enhanced approximately 8-fold in the visible region. XRD patterns reveal the ZnS(111)-oriented phase is dominant. Furthermore, dense, crack-free ZnS:TbOF grains are observed by SEM. The results imply that the SiO2 buffer layer sandwiched between the ZnS:TbOF and Bi4Ti3O2 layers effectively separates the two layers. Therefore, interdiffusion and chemical reactions are prevented at the interface of the two layers, and the crystalline characteristics of the ZnS:TbOF layer and the optical transmittance of the specimen are improved as a result. Finally, the dielectric constant of the stacked structure is lower than that of the single layer structure without SiO2, but the dielectric breakdown strength is enhanced.

EFFECT OF ANNEALING TREATMENT ON FERROELECTRIC AND ELECTRICAL CHARACTERISTICS OF Bi4-XLaXTi3O12 THIN FILMS ON ITO/GLASS SUBSTRATE

“…However, such as BST and BZT thin films were most expected materials to substitute the PZT and SBT memory materials because the PZT and SBT exhibit the high pollution problem [5][6][7][8][9][10][11][12][13]. The subject of this work is to study the characteristics of thin films of perovskite oxide BLT thin films deposited on transparent conductive thin film of ITO glass substrate using the rf magnetron sputtering method.…”

Effect of Oxygen Concentration on Characteristics of Ba(Zr0.1Ti0.9)O3Thin Films Deposited on Indium Tin Oxide/Glass Substrates

“…In a previous study, the bismuth elements and evaporation effects on the electrical and physical characteristics of as-deposited Bi 4 Ti 3 O 12 thin films on indium tin oxide (ITO) glass substrates were determined and discussed. 5) In this study, the electrical and physical characteristics of perovskite oxide Ba(Zr 0:1 Ti 0:9 )O 3 (BZ1T9) thin films deposited on ITO glass substrates by rf magnetron sputtering are discussed. Additionally, the physical and electrical properties of Al/ Ba(Zr 0:1 Ti 0:9 )O 3 /ITO glass (MFM) structures are discussed and investigated for different oxygen concentrations.…”