This PDF file contains the front matter associated with SPIE Proceedings Volume 10351, including the Title Page, Copyright information, Table of Contents, Introduction (if any), and Conference Committee listing.
ArF excimer lasers with short wavelength and high photon energy are widely applied in the field of integrated circuit lithography, material processing, laser medicine, and so on. Excimer laser single pulse energy is a very important parameter in the application. In order to detect the single pulse energy on-line, one energy detector based on photodiode was designed. The signal processing circuit connected to the photodiode was designed so that the signal obtained by the photodiode was amplified and the pulse width was broadened. The amplified signal was acquired by a data acquisition card and stored in the computer for subsequent data processing. The peak of the pulse signal is used to characterize the single pulse energy of ArF excimer laser. In every condition of deferent pulse energy value levels, a series of data about laser pulses energy were acquired synchronously using the Ophir energy meter and the energy detector. A data set about the relationship between laser pulse energy and the peak of the pulse signal was acquired. Then, by using the data acquired, a model characterizing the functional relationship between the energy value and the peak value of the pulse was trained based on an algorithm of machine learning, Support Vector Regression (SVR). By using the model, the energy value can be obtained directly from the energy detector designed in this project. The result shows that the relative error between the energy obtained by the energy detector and by the Ophir energy meter is less than 2%.
We present a study on the. formation of p-type ZnO thin film through ion implantation. Group V dopants (N, P) with different ionic radii are implanted into chemical vapor deposition grown ZnO thin film on GaN/sapphire substrates prior to thermal activation. It is found that monodoped ZnO by N+ implantation results in n-type conductivity under thermal activation. Dual-doped ZnO film with a N: P ion implantation dose ratio of 4:1 is found to be p-type under certain thermal activation conditions. Higher p-type activation levels (1019 cm(-3)) under a. wider thermal activation range are found for the N/P dual-doped ZnO film co-implanted by additional oxygen ions. From high resolution x-ray diffraction and x-ray photoelectron spectroscopy it is concluded that the observed p-type conductivities are a result of the promoted formation of P-Zn-4N(O) complex defects via the. concurrent substitution of nitrogen at oxygen sites and phosphorus at zinc sites. The enhanced solubility and stability of acceptor defects in oxygen co-implanted dual-doped ZnO film are related to the reduction of oxygen vacancy defects at the surface. Our study demonstrates the prospect of the. formation of stable p-type ZnO film through co-implantation.
To research the attenuation performance of the AlGaN photocathode, three samples with same structures grown by metalorganic chemical vapor deposition (MOCVD) were activated with three different activation methods, which are Cs-only, Cs-O and Cs-O-Cs activation, respectively. The spectral responses and attenuated photocurrents of three AlGaN photocathodes were measured, the result shows that the Cs-O activated AlGaN photocathode have the lowest attenuation speed in the first few hours, the next are Cs-O-Cs and Cs-only activation, respectively. After the Cs-O-Cs activation sample has attenuated 90 min, its attenuation photocurrent curve is coincident with the Cs-O activation sample in the next measurement. The main factor which affects the photocurrent attenuation is Cs atom desorbed from the photocathodes surface.
The far-ultraviolet (FUV) region, which is the region of 120-300 nm, provides unique information about the electronic transitions and structure of a molecule. We have recently succeeded in measuring electronic spectra of graphene, carbon nanotubes, and polymer nanocomposites down to 150 nm using a newly developed attenuated total reflection (ATR)-UV spectrometer. The spectra of graphene show a thickness dependence. A thin graphene sample with the thickness of 1-2 nm shows a small peak near 155 nm. Single-wall carbon nanotubes with the thickness of 1-2 nm yields a similar peak. We investigate band assignments for these peaks including theoretical calculation. In the case of polymer nanocomposites a polymer gives rise to major peaks below 200 nm while nano carbon part does not show a peak in the whole region because the content of nanocarbon is very small compared with the polymer. We compared an FUV-DUV spectrum of PHB (poly(hydroxybutyrate))-graphene nanocomposites with that of PHB. A peak near 171 nm shows a longer wavelength shift by ca. 2 nm upon the formation of nanocomposites, indicating a change in electronic structure in the polymer. We investigate the cause of the shift by using quantum chemical calculations.
Plasmonics in the UV-range constitutes a new focus of research due to new challenges arising in fields such as biology, chemistry or spectroscopy. Very recent studies point out gallium and rhodium as good candidates for these purposes because of their low oxidation tendency and at the same time, having a good plasmonic response in the UV and excellent photocatalytic properties. Here we present an overview of the current state of UV-plasmonics with our latest findings in the plasmonic activity of materials like gallium and rhodium.
An electromagnetic field is able to produce a collective oscillation of free electrons at a metal surface. This allows light to be concentrated in volumes smaller than its wavelength. The resulting waves, called surface plasmons can be applied in various technological applications such as ultra-sensitive sensing, Surface Enhanced Raman Spectroscopy, or metal-enhanced fluorescence, to name a few. For several decades plasmonics has been almost exclusively studied in the visible region by using nanoparticles made of gold or silver as these noble metals support plasmonic resonances in the visible and near-infrared range. Nevertheless, emerging applications will require the extension of nano-plasmonics toward higher energies, in the ultraviolet range. Aluminum is one of the most appealing metal for pushing plasmonics up to ultraviolet energies. The subsequent applications in the field of nano-optics are various. This metal is therefore a highly promising material for commercial applications in the field of ultraviolet nano-optics. As a consequence, aluminum (or ultraviolet, UV) plasmonics has emerged quite recently. Aluminium plasmonics has been demonstrated efficient for numerous potential applications including non-linear optics, enhanced fluorescence, UV-Surface Enhanced Raman Spectroscopy, optoelectronics, plasmonic assisted solid-state lasing, photocatalysis, structural colors and data storage. In this article, different preparation methods developed in the laboratory to obtain aluminum nanostructures with different geometries are presented. Their optical and morphological characterizations of the nanostructures are given and some proof of principle applications such as fluorescence enhancement are discussed.
The wavelength region shorter than 200 nm, far-ultraviolet (FUV) region, is very rich in information about the electronic states and structure of a molecule. We have recently developed a totally new UV spectrometer based on attenuated total reflection (ATR) that enables us to measure spectra of liquid and solid samples in the 140–280 nm region. This paper shows the studies by the attenuated total reflection far-ultraviolet (ATR-FUV) spectroscopy. Intermolecular interactions between alkyl chains such as CH---HC should be reflected in the phase behavior of organic compounds. We measured the attenuated total reflectance spectra in the far-UV region (145–300 nm) of n-tetradecane (Tm = 5.9 °C) from 15 to -38 °C to determine its temperature dependency. With decreasing temperature, the absorption band at 153 nm in the liquid phase becomes weaker and new bands appear at around 200 and 230 nm. These results suggest that an unusually compressed structure might be generated at the surface at low temperatures, and this phase change, which is reversible, is responsible for the unusual absorption observed in the ATR-FUV spectra. We have also investigated composite polymer electrolytes (CPE). ATR-FUV spectra of CPEs composed of Poly(ethylene oxide) (PEO) and Li salt were observed and its variation of anions for the CPEs are studied.