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In this study, Nb2O5 ceramic was used as the target to deposit the Nb2O5 thin films on glass substrates with the radio frequency (RF) magnetron sputtering method. Different deposition temperatures and O2 ratios were used as parameters to investigate the optical properties of Nb2O5 thin films. The deposition parameters were a pressure of 5 × 10−3 Torr, a deposition power of 100 W, a deposition time of 30 min, an O2 ratio (O2/(O2 + Ar), in sccm) of 10% and 20%, and deposition temperatures of room temperature (RT), 200, 300 and 400 °C, respectively. We found that even if the deposition temperature was 400 °C, the deposited Nb2O5 thin films revealed an amorphous phase and no crystallization phase was observed. The optical properties of transmittance of Nb2O5 thin films deposited on glass substrates were determined by using a ultraviolet-visible (UV-vis) spectrophotometer (transmittance) and reflectance spectra transmittance (reflectance, refractive index, and extinction coefficient) in the light wavelength range of 250–1000 nm. When the O2 ratio was 10% and the deposition temperature increased from RT to 200 °C, the red-shift was clearly observed in the transmittance curve and the transmission ratio had no apparent change with the increasing deposition temperature. When the O2 ratio was 20%, the red-shift was not observed in the transmittance curve and the transmission ratio apparently decreased with the increasing deposition temperature. The variations in the optical band gap (Eg) values of Nb2O5 thin films were evaluated from the Tauc plot by using the quantity hν (the photon energy) on the abscissa and the quantity (αhν)r on the ordinate, where α is the optical absorption coefficient, c is the constant for direct transition, h is Planck’s constant, ν is the frequency of the incident photon, and the exponent r denotes the nature of the transition. As the O2 ratio of 10% or 20% was used as the deposition atmosphere, the measured Eg values decreased with the increase of the deposition temperature. The reflectance ratio, extinction coefficient, and refractive index curves of Nb2O5 thin films were also investigated in this study. We would show that those results were influenced by the deposition temperature and O2 ratio.

In this study, Ga2O3-doped ZnO (GZO) thin films were deposited on glass and flexible polyimide (PI) substrates at room temperature (300 K), 373 K, and 473 K by the radio frequency (RF) magnetron sputtering method. After finding the deposition rate, all the GZO thin films with a nano-scale thickness of about 150 ± 10 nm were controlled by the deposition time. X-ray diffraction patterns indicated that the GZO thin films were not amorphous and all exhibited the (002) peak, and field emission scanning electron microscopy showed that only nano-scale particles were observed. The dependences of the structural, electrical, and optical properties of the GZO thin films on different deposition temperatures and substrates were investigated. X-ray photoemission spectroscopy (XPS) was used to measure the elemental composition at the chemical and electronic states of the GZO thin films deposited on different substrates, which could be used to clarify the mechanism of difference in electrical properties of the GZO thin films. In this study, the XPS binding energy spectra of Ga2p3/2 and Ga2p1/2 peaks, Zn2p3/2 and Zn2p1/2 peaks, the Ga3d peak, and O1s peaks for GZO thin films on glass and PI substrates were well compared.

We investigated the structural, optical, and electrical properties of amorphous IGZO/silver/amorphous IGZO (α-IGZO/Ag/α-IGZO) triple-layer structures that were deposited at room temperature on Eagle XG glass and flexible polyethylene terephthalate substrates through the sputtering method. Thin Ag layers with different thicknesses were inserted between two IGZO layers to form a triple-layer structure. Ag was used because of its lower absorption and resistivity. Field emission scanning electron microscopy measurements of the triple-layer structures revealed that the thicknesses of the Ag layers ranged from 13 to 41 nm. The thickness of the Ag layer had a large effect on the electrical and optical properties of the electrodes. The optimum thickness of the Ag metal thin film could be evaluated according to the optical transmittance, electrical conductivity, and figure of merit of the electrode. This study demonstrates that the α-IGZO/Ag/α-IGZO triple-layer transparent electrode can be fabricated with low sheet resistance (4.2 Ω/□) and high optical transmittance (88.1%) at room temperature without postannealing processing on the deposited thin films.

Abstract:In this study, BaZrO 3 :Eu 0.025 powder was synthesized through the solid-state reaction method with two different heating processes. For the one-step process, the BaZrO 3 :Eu 0.025 powder was heated to 1000˝C-1400˝C for 2 h. For the two-step heating process, the BaZrO 3 :Eu 0.025 powder was pre-heated at 800˝C for 2 h, after being cooled to room temperature and ground, then the powder was heated to 1000˝C-1400˝C again for 2 h. The optimum excitation optical wavelength of BaZrO 3 :Eu 0.025 powders were 271 nm and the maximum intensity of the emission spectrum of BaZrO 3 :Eu 0.025 powders increased with increasing heating temperature. The all-heated BaZrO 3 :Eu 0.025 powders showed two strong orange emission bands peaking at the wavelengths of 574 and 596 nm and two weak emission bands peaking at 620 and 650 nm. As the heating temperatures were 1300˝C and 1400˝C, the maximum intensity of one-step heating BaZrO 3 :Eu 0.025 powders appeared at the 5 D 0 -7 F 0 (574 nm) and the maximum intensity of one-step heating BaZrO 3 :Eu 0.025 powders appeared at the 5 D 0 -7 F 1 (596 nm) transitions of Eu 3+ ions, respectively.

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Zengwun estuary in Taiwan is a key habitat for the endangered black-faced spoonbill (Platalea minor), a piscivorous migratory bird. In the winters 2011-2012 and 2012-2013, the percentages were nearly half of that in 2007-2008 (65.5% and 51.1%). To find the reasons of the decline of the habitats is important for the preservation of the endangered bird. So, we used an unsupervised classification method to analyze high spatiotemporal satellite images from FORMOSAT-2 from 2004 to 2013, and found that the quality of spoonbill habitats has deteriorated. The deterioration mainly caused by many of the fishponds there, changing the raised fish from milkfish to grouper fish for the purpose of business benefit in recent 3 years. The water depth in the fishponds, which raised milkfish, used to be kept below 30 cm for the convenience in harvesting in winter. Besides, they left the uneconomical small fish behind in the ponds, which provided the black-faced spoonbills good places to forage. However, after the fishponds were changed to raise grouper fish, it not only made the small fish no more exist in the ponds, but also the developing engineering to deepen the fishponds made the trees around these ponds been cleaned. These trees could have provided shields for the black-faced spoonbills against chilly wind. As a consequence, these changes have substantially reduced the agreeable region where the depth of water should be less than 30cm for black-faced spoonbill to forage and inhabit. New reserves for spoonbills have been established recently in Taiwan. Nevertheless, a detailed plan for maintaining food resources for spoonbills as well as returning them habitats, must be implemented immediately.

In this study, the raw materials of BaCO 3 and ZrO 2 powders with different average diameters were used to prepare BaZrO 3 :Eu 0.025 phosphors by the solid-state reaction method. The raw materials with different average diameters were prepared by mixing them by the ball milling method and/or grinding them in a nanoscale grinding machine. As different grinding processes were used, the BaCO 3 and ZrO 2 powders had the average diameters of 2124, 707, 645, and 496 nm. When raw materials with the average diameter of 2124 nm were used and the calcination temperature was changed from 1100 to 1400 °C, the BaZrO 3 :Eu 0.025 phosphors showed two strong orange emission bands with peaks at the wavelengths of 574 and 596 nm and two weak emission bands with peaks at 620 and 650 nm. The maximum intensity of the emission spectrum of the BaZrO 3 :Eu 0.025 phosphors increased with increasing calcination temperature. When the raw materials with the average particle sizes of 707, 645, and 496 nm were used and the calcination temperature was changed from 950 to 1150 °C, the BaZrO 3 :Eu 0.025 phosphors showed one broad blue emission band with central wavelengths located at 464-466 nm. In this study, we prove that when the sizes of the source materials are different, the luminescence properties of the BaZrO 3 :Eu 0.025 phosphors will have large variations after they are calcined at different temperatures.