D. Louloudakis; D. Davazoglou;E. Koudoumas; D. Vernardou; G. Papadimitropoulos
Abstract
Monoclinic electrochromic tungsten trioxide (WO3) layers were grown on FTO substrates using a Low-Pressure Chemical Vapor Deposition (LPCVD) system. The effect of the deposition temperature on the structural and morphological characteristics as well as the electrochromic response of the layers was examined. ...
Read More
Monoclinic electrochromic tungsten trioxide (WO3) layers were grown on FTO substrates using a Low-Pressure Chemical Vapor Deposition (LPCVD) system. The effect of the deposition temperature on the structural and morphological characteristics as well as the electrochromic response of the layers was examined. It was found that increasing deposition temperature improves the crystallinity of the layers which affects their electrochemical/electrochromic behavior.
Abstract
The motivation of this work is to apply a new model, which we had called the Global Reactions Model (GRM), for the theoretical study of the optical and electronics properties of Silicon Rich Oxides (SRO) structures regardless of the technique used to fabricate such structures. Recently we published the ...
Read More
The motivation of this work is to apply a new model, which we had called the Global Reactions Model (GRM), for the theoretical study of the optical and electronics properties of Silicon Rich Oxides (SRO) structures regardless of the technique used to fabricate such structures. Recently we published the Global Reactions Model (GRM) to describe a set of chemical reactions that could hypothetically occur during the process of obtaining silicon rich oxide (SRO) films, notwithstanding of the technique used to grow such films. Particularly, chemical reactions that occur during the process of growing of SRO films by Low Pressure Chemical Vapor Deposition (LPCVD) and Hot Filament Chemical Vapor Deposition (HFCVD) techniques were emphasized in these models. We suggest and evaluate either some types of molecules or resulting nanostructures and we have predicted theoretically, by applying the density functional theory (DFT), the contribution that they may have to the phenomenon of luminescence. We calculated the luminescent spectra of the as grown and the annealed structures. In this work we focused in siloxanes species presumably found in SRO.
Hyun-Je Sung; Sang-Chul Jung;Jung-Sik Kim; Byung-Min Ki
Abstract
The photocatalytic behaviors of TiO2-supported on the long lasting phosphor beads were examined. Nanocrystalline TiO2 was coated on ellipsoidal-spherical beads of an alkaline earth aluminate phosphor, Sr4Al14O25:Eu 2+ , Dy 3+ , by low pressure chemical vapor deposition (LPCVD). The photocatalytic reaction ...
Read More
The photocatalytic behaviors of TiO2-supported on the long lasting phosphor beads were examined. Nanocrystalline TiO2 was coated on ellipsoidal-spherical beads of an alkaline earth aluminate phosphor, Sr4Al14O25:Eu 2+ , Dy 3+ , by low pressure chemical vapor deposition (LPCVD). The photocatalytic reaction was examined by measuring the decomposition of benzene and toluene gases by gas chromatography under ultraviolet, visible light (λ> 410 nm) irradiation, as well as in the dark. The LPCVD TiO2-coated Sr4Al14O25:Eu 2+ , Dy 3+ showed an active photocatalytic reaction under visible irradiation. The mechanisms of the photocatalytic reactivity for the TiO2-coated Sr4Al14O25:Eu 2+ , Dy 3+ phosphor beads were discussed in terms of the crystal structure at the interface, energy band structure and phosphorescence. The coupling of TiO2 with the Sr4Al14O25:Eu 2+ , Dy 3+ phosphor resulted in energy band bending in the junction region between TiO2 and Sr4Al14O25:Eu 2+ , Dy 3+ phosphor, which makes the TiO2 crystal at the interface photo-reactive under visible light irradiation. The LPCVD TiO2-coated Sr4Al14O25:Eu 2+ , Dy 3+ phosphor beads were also photo-reactive in the dark through the light photons emitted from the Sr4Al14O25:Eu 2+ , Dy 3+ phosphor.
)