apermanent anti-graffiti clear polyurethane coating, using a silicone additive, was prepared and studied. various techniques, such as contact angle measurements and edx were employed to characterize and investigate thesurface properties of the coatings. the results revealed that with inclusion of silicon additive to clear coating, according to wu method, surface free energy was decreased from 4...

An ultra-low anti-reflection optical coating on both surfaces of a plastic cover slip was studied for use in confocal image measurement. The optical reflectance at a wavelength of 632.8 nm was less than 0.1% when the coated sample was placed in a liquid having a refractive index of 1.34 close to the aqueous solution of the biomaterial. The highand low-index coating films, Substance-2 (PrTiO3) a...

We report here several different superlattice photonic crystal based designs for 200nm thick c-Si solar cells, demonstrating that these structures have the ability to increase broadband absorption from λ = 300nm to 1100nm by more than 100% compared to a planar cell with an optimized anti-reflection coating. We show that adding superlattices into photonic crystals introduces new optical modes th...

A near-infrared spectroscopic method and measurement system for moisture depth profiling is presented in this thesis. The measurement system is based on a fibre-optic light source and probes, and a hyperspectral imaging spectrograph. The probes feature six different measurement geometries, including a specular reflection measurement, and diffuse reflection and transmission measurements, all of ...

Major part of this work was carried out in Hsinchu. ABSTRACT Mask-making process using laser direct-write has been broadly applied in the microelectronics and the PC board industries. In this paper, we report the thick-film lithography of laser write mainly for the x-ray mask in the LIGA application. Several schemes of multiple writing are successfully demonstrated in terms of the sidewall stra...

Improving the efficiency of solar cells through novel materials and devices is critical to realize the full potential of solar energy to meet the growing worldwide energy demands. We present here a highly efficient radial p-n junction silicon solar cell using an asymmetric nanowire structure with a shorter bottom core diameter than at the top. A maximum short circuit current density of 27.5 mA/...

Visible light photon counters (VLPCs) and solid-state photomultipliers (SSPMs) are high-efficiency single-photon detectors which have multi-photon counting capability. While both the VLPCs and the SSPMs have inferred internal quantum efficiencies above 93%, the actual measured values for both the detectors were in fact limited to less than 88%, attributed to in-coupling losses. We are currently...

Designs of multilayer antireflection coatings made from co-sputtered and low-refractive-index materials are optimized using a genetic algorithm. Co-sputtered and low-refractive-index materials allow the fine-tuning of refractive index, which is required to achieve optimum anti-reflection characteristics. The algorithm minimizes reflection over a wide range of wavelengths and incident angles, an...

This report focuses on the design, application, and testing of custom beamsplitter and anti-reflection coatings for use in the Magdalena Ridge Observatory Interferometer (MROI) beam combiners. The coatings were designed in collaboration with Optical Surface Technologies, and the University of Cambridge. The fringe tracker and science combiners will operate across the J, H, and K bands. The coat...

Polyelectrolyte multilayered (PEM) films created by an aqueous-based layer-by-layer assembly technique have been widely studied in the past decade. Owing to the simple, versatile and yet well-controlled nature of this technique, many potential applications of these thin films have also been proposed and explored. This thesis presents a recent work in fabricating nanoporous PEM films with superh...