A study on low-refractive-index SiO2 antireflective (AR) coatings by a sol-gel method is reported. Variations in the properties of the coatings are related to the molar ratios of ammonia to deionized water being changed in the process of preparing the sols. From the performance test results, the optimal ratio of the reactants necessary to prepare low-refractive-index SiO2 AR coatings is determined. Of all the SiO2 AR coatings, the lowest recorded refractive index is 1.16 at a wavelength of 700 nm. The largest water contact angle is 121.2°, and the peak transmittance is 99.95% at a wavelength of 908 nm. Furthermore, the sol used to deposit the film with the lowest refractive index is stable because of the narrow size distribution of its constituent particles.

YbF3 is proposed as a substitute for ThF4 in anti-reflection or reflection coatings in the infrared (IR) range. In this letter, we study on the properties of the YbF3 thin film deposited with different deposition parameters, and find the deposition rate of YbF3 has a large effect on the substrate particles deposition both on number and area. Moreover, we find the deposition temperature is a main factor of element content. In the end, we produce an anti-reflection coating on Ge substrate, and its average transmission reaches 99.5%, which can satisfy the practical requirement.

This contribution presents a magnetron sputter deposition tool with broadband optical monitor and online re-optimization capability for high volume production. The layer termination relies on a comparison of the actually measured reflection spectrum with a pre-calculated target spectrum. Spectra recorded after each deposited layer are analyzed by the re-optimization module and–in case of significant deviations–layer thicknesses and target spectra for the remaining layers are recalculated. This technique significantly improves the performance and reproducibility in case of highly demanding coating designs and is able to correct abnormal production errors in individual layers, which will lead to coating failure without reoptimization.

Fabrication of Ag or Au nanocolumns by oblique angle deposition (OAD) is now prevalent for their surface enhanced Raman scattering (SERS) property and their biosensor application. However, the size, shape, and the density of nanocolumns are not directed in a desired way. To sufficiently realize the growth process controlled by multiple physical factors like deposition angle (\alpha), substrate temperature (T), and deposition rate (F), we develop a three-dimensional (3D) kinetic Monte Carlo (KMC) model for simulating processes of Ag nanocolumnar growth by oblique angle deposition. The dependences of nanocolumnar morphologies on these factors are analyzed. The mimical results reach a reasonable agreement with the experimental morphologies generated by OAD.

The influence of technique parameters on the temperature coefficient of resistance (TCR) of reduced graphene oxide (RGO) films is studied. These technique parameters include the ultrasonic time, solution concentration, and heat treatment temperature. Results show that, the best technique parameters are ultrasonic time of 14 h, solution of 0.12 ml, and annealing temperature of 800 oC, and on this point, TCR value of RGO is from -0.67% to -1.36% at the different film thicknesses.

A linear zone plate named multilayer laue lens (MLL) is fabricated using a depth-graded multilayer structure. The lens shows considerable potential in focusing an X-ray beam into a nanometer scale with high efficiency. In this letter, a depth-graded multilayer consisting of 324 alternating WSi2 and Si layers with a total thickness of 7.9 \mu m is deposited based on the thickness sequence according to the demands of the zone plate law. Subsequently, the multilayer sample is sliced and thinned to an ideal depth along the cross-section direction using raw abrasives and diamond lapping. Finally, the cross-section is polished by a chemical mechanical polishing (CMP) technique to remove the damages and improve the surface smoothness. The final depth of the MLL is approximately 7 μm with an achieved aspect ratio greater than 400. Results of scanning electron microscopy (SEM) and atomic force microscopy (AFM) indicate that interfaces are sharp, and the multilayer structure remains undamaged after the thinning and polishing processes. The surface roughness achieved is 0.33 nm.

Pure zinc blende structure GaAs/AlGaAs axial heterostructure nanowires (NWs) are grown by metal organic chemical vapor deposition on GaAs(111) B substrates using Au-catalyzed vapor-liquid-solid mechanism. Al adatom enhances the influence of diameters on NWs growth rate. NWs are grown mainly through the contributions from the direct impingement of the precursors onto the alloy droplets and not so much from adatom diffusion. The results indicate that the droplet acts as a catalyst rather than an adatom collector.

A new technique for rapid 3D microstructure preparation using micropipette is investigated. The tool electrode is made by Pt-Ir wire directly inserted into one or several glass micropipettes arrayed together. This electrode is used as anode, and copper plate or indium tin oxide (ITO) film is used as cathode. Both of them are placed in mixed electrolytes of CuSO4 and H2SO4 for electrochemical microdeposition. To apply voltage between the electrodes, copper microcolumn with controllable diameter and height is successfully deposited into the cathode substrate by lifting the anode in Z direction. Moreover, micropatterns can be made by moving the anode on XY plane, sustaining a gap of a few microns from the substrate. Experiments are carried out to check the feasibility of this method. Microcolumns 50?150 μm in diameter with aspect ratio (height/diameter) that can be greater than 50 are fabricated. Several copper microcolumns that grow simultaneously are obtained. Moreover, lines with micro-width are also fabricated on ITO film. The experimental results indicate that this method is simple, fast, efficient, and can be mass-produced. It can be widely used for micro/nano deposition and processing.