In this paper, we propose a broadband omnidirectional near-perfect absorber that transforms light energy into heat. In contrast to previous research on structural metamaterials, this study focuses on light absorption in the epsilon-near-zero (ENZ) layers without any structural patterns. Chromium (Cr) thin films were applied as ENZ layers.
View Article and Find Full Text PDFIn this study, we report the fabrication of aluminum oxide-coated glass (ACG) slides for the preparation of glycan microarrays. Pure aluminum (Al, 300 nm) was coated on glass slides via electron-beam vapor deposition polymerization (VDP), followed by anodization to form a thin layer (50-65 nm) of aluminum oxide (Al-oxide) on the surface. The ACG slides prepared this way provide a smooth surface for arraying sugars covalently via phosphonate formation with controlled density and spatial distance.
View Article and Find Full Text PDFIn this study, a controllable photonic mirror was fabricated using the atomic layer deposition (ALD) coating technique on a polystyrene (PS) nanosphere template. PS nanospheres were self-assembled on an Al/glass substrate to form the bottom electrode. A 20 nm ALD Al2O3 film was then coated onto the surface of the reduced PS nanosphere structure.
View Article and Find Full Text PDFThe refractive index and extinction coefficient are the most important optical characteristics of optical thin-film materials. Optical coating devices with excellent performance are achieved more easily when the selected materials have relatively high refractive index contrast. Here, we used an annealing method to fabricate low-refractive-index material in a multilayer structure originated from the Kirkendall effect.
View Article and Find Full Text PDFAn orderly inclined Al2O3 column array was fabricated by atomic layer deposition and sequential electron beam evaporation using a hollow nanosphere template. The transmittance spectra at various angles of incidence were obtained through the use of a Perkin-Elmer Lambda 900 UV/VIS/NIR spectrometer. The inclined column array could display the image information through a scattering mechanism and was transparent at high viewing angles along the deposition plane.
View Article and Find Full Text PDFConductive and transparent multilayer thin films consisting of three alternating layers (TiO2/Ag/SiO2, TAS) have been fabricated for applications as transparent conducting oxides. Metal oxide and metal layers were prepared by electron-beam evaporation with ion-assisted deposition, and the optical and electrical properties of the resulting films as well as their energy bounding characteristics and microstructures were carefully investigated. The optical properties of the obtained TAS material were compared with those of well-known transparent metal oxide glasses such as ZnO/Ag/ZnO, TiO2/Ag/TiO2, ZnO/Cu/ZnO, and ZnO/Al/ZnO.
View Article and Find Full Text PDFTransparent conducting ZnO/Ag/ZnO multilayer electrodes having electrical resistance much lower than that of widely used transparent electrodes were prepared by ion-beam-assisted deposition (IAD) under oxygen atmosphere. The optical parameters were optimized by admittance loci analysis to show that the transparent conducting oxide (TCO) film can achieve an average transmittance of 93%. The optimum thickness for high optical transmittance and good electrical conductivity was found to be 11 nm for Ag thin films and 40 nm for ZnO films, based on the admittance diagram.
View Article and Find Full Text PDFWe fabricated an orderly inclined Al2O3 column array using a hollow microsphere template. The microstructure and optical properties were investigated with scanning electron micrography and a UV/VIS spectrometer, respectively. Microsphere shell templates were formed using atomic layer deposition to prevent the melting of polystyrene microspheres during the following high-temperature deposition process.
View Article and Find Full Text PDFMgF(2) films with a columnar microstructure are obliquely deposited on glass substrates by resistive heating evaporation. The columnar angles of the films increases with the deposition angle. Anisotropic stress does not develop in the films with tilted columns.
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