This PDF file contains the front matter associated with SPIE Proceedings Volume XXXX, including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing.

Effects of rapid thermal annealing (RTA) and dual compression-pulse-laser sintering (compression-PLS) on photovoltaic, CdTe nanowire (NW) and quantum dot (QD) films are investigated. Unlike regular furnace annealing, RTA involves raising the temperature of a substrate’s atmosphere by several hundred degrees in a matter of seconds, letting it sit for 30 to 120 seconds, then cooling it back to T₀. To the best of our knowledge, such treatments of CdTe nanocrystal (NC) films have not been documented. In compression-PLS, a large pressure (MPa) is applied to a film through a laser-pulsing mechanism. Next, a high-energy, high frequency laser beam is pulsed onto it for sintering. During the compression, we used a single pulse of 5 nanoseconds. For the sintering, we used a 7.05 mJ beam for two pulses, at 25 ns per pulse. Such parameters were determined from SEM and other preliminary film characterization results. Morphology, material content, and conductivity of the films are analyzed before and after treatment using tunneling and scanning electron microscopy, EDS, and two-probe measurements, respectively. This study provides new knowledge regarding the morphological and structural outcomes of RTA and compression-PLS on CdTe nanoparticle films. Furthermore, RTA and compression-PLS can increase the film electrical conductivity by improving their contact with each other. We found that RTA partially sinters the film and enhances inplane current density by a factor of ~1.7, for a values on the order of ~10^-7A/cm². Compression-PLS successfully sinters the NW film and improves current density up to a factor of ~167, for values on the order of ~10^-5 A/cm². On the other hand, QD films do not exhibit current density improvement with treatments. These values remain on the order of ~10^-7 A/cm². The resistivities of the sintered NW films reach as low as 6.7*10⁶ Ω*cm, while the RTA’d NW film has a resistivity on the order of 10⁸ Ω*cm. These values are comparable to values of bulk and thin-film CdTe: single crystalline, undoped CdTe resistivity values range from 10⁵ to 10⁸ Ω*cm,^8,9 while polycrystalline thin-film values range from 10⁴ to 10⁶ Ω*cm.^11,12 The QD films also have comparable resistivities to these results, albeit on the higher side.

Metallic nanowires of rectangular cross-section can operate as isolated or arrayed optical monopole or dipole antennas, and when deposited on a Si substrate and covered with water, become useful as (bio)chemical sensors. The optical performance of such antennas is assessed over a broad wavelength range as a function of geometrical parameters, including wire thickness, width, length, and gap (in the case of dipoles). Effects caused by varying the pitch of twodimensional arrays of antennas are also determined. Given a uniform broadside excitation, antennas resonate in the main mode of propagation of the corresponding asymmetric metal stripe waveguide, and antennas performance is related to its propagation characteristics. The structures considered are amenable to fabrication via metal evaporation and lift-off, with the nanowires defined by electron beam patterning.

Nanostructured carbon materials have increasingly attracted the interest of the scientific community, because of their fascinating physical properties and potential applications in high-tech devices. In the current ITER design, the tiles made of carbon fiber composites (CFCs) are foreseen for the strike point zone and tungsten (W) for other parts of the divertor region. This choice is a compromise based mainly on experience with individual materials in many different tokamaks. Also Carbon-Aluminum composites are the candidate material for the First Wall in ITER. In order to prepare nanostructured carbon-aluminum nanocomposite for the divertor part in fusion applications, the original method thermionic vacuum arc (TVA) was used in two electronic guns configuration. One of the main advantages of this technology is the bombardment of the growing thin film just by the ions of the depositing film. Moreover, the energy of ions can be controlled. Thermo-electrons emitted by an externally heated cathode and focused by a Wehnelt focusing cylinder are strongly accelerated towards the anode whose material is evaporated and bright plasma is ignited by a high voltage DC supply. The nanostructured C-Al films were characterized by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM). Tribological properties in dry sliding were evaluated using a CSM ball-on-disc tribometer. The carbon - aluminum films were identified as a nanocrystals complex (from 2nm to 50 nm diameters) surrounded by amorphous structures with a strong graphitization tendency, allowing the creating of adherent and wear resistant films. The friction coefficients (0.1 - 0.2, 0.5) of the C-Al coatings was decreased more than 2-5 times in comparison with the uncoated substrates proving excellent tribological properties. C-Al nanocomposites coatings were designed to have excellent tribological properties while the structure is composed by nanocrystals complex surrounded by amorphous structures with a strong graphitization tendency, allowing the creating of adherent and wear resistant films.

A study of the fluorescence and Raman spectra of a new and complex drug delivery system formed by emodin adsorbed on silver nanoparticles embedded into a matrix of porous silicon is here reported. Several experimental methods of inclusion of the drug-silver set inside the pores, without previous functionalization of porous silicon, have been tested in order to optimize the conditions for the fluorescence detection of emodin. In this sense, we have also added bovine serum albumin to the system, finding that the presence of the protein enhances the fluores-cence signal from emodin.

A layered structured made of a dielectric waveguide and a layer of metal was studied from the point of view of the guided modes. A detailed asymptotic study of the dispersion curve was given.

In earlier work, the transfer matrix method (TMM) and the angular plane wave spectrum method (APWS) have been used to analyze plane wave and beam propagation in a multilayer structure consisting of positive index and negative index materials. In this paper, we demonstrate the use the complex Poynting theorem (CPT) to validate numerical calculations by the TMM and APWS methods. Application of CPT also gives physical insight into the power balance inside such structures which may possess complex permittivities and permeabilities, and have propagating and nonpropagating waves.

Superhydrophobic surfaces were produced on glass with self-cleaning and wide-angle anti-reflection in the near-infrared (1.0-2.1μm). These properties resulted from a combination of surface energy and nano/micro-structured topology based on silica nanoparticles (NPs), index grading and interference. In a two-layer approach (glass/silica NPs/PTFE), a water contact angle (WCA) of 169^°±2^°was attained with very low hysteresis (≤ 2^°), as well as high transmittance (93-94% at normal incidence). In a three-layer approach (glass/silica NPs/silica aerogel/PTFE), surfaces were produced with WCA of 158^°±2^°, also very low hysteresis (< 5^°), and significant antireflection. This allowed for a normal transmittance of 99.5% or higher, which decreased less than 2% at +20^° incidence. These results show that pronounced wide-angle antireflection and self-cleaning properties can be simultaneously attained by proper glass coating. Present advantages and limitations for potential applications are discussed.

This research is focused on the fabrication of thin films followed by Surface Enhanced Raman Spectroscopy (SERS) testing of these films for various applications. One technique involves the mixture of nanoparticles with twophoton material to be used as an indicator dye. Another method involved embedding silver nanoparticles in a ceramic nano-membrane. The substrates were characterized by both Atom Force Microscopy (AFM) and Scanning Electron Microscopy (SEM). We applied the nanostructured substrate to measure the SERS spectra of 10^-6 Mol/L Rhodomine 6G(Rh6G), e-coli bacteria and RDX explosive. Our results showed that silver coated ceramic membranes can serve as appropriate substrates to enhance Raman signals. In addition, we demonstrated that the in-house-made colloidal silver can work for enhancement of the Raman spectra for bacteria. We measured the Raman spectra of Rh6G molecules on a substrate absorbed by a nanofluid of silver. We observed several strong Raman bands – 613cm-¹,768 cm^-1,1308cm^-1 1356 cm^-1,1510cm^-1, which correspond to Rh6G vibrational modes υ₅₃,υ6₅,υ1₁₅,υ₁₁₇,υ₁₄₆ respectively, using a ceramic membrane coated by silver. The Raman spectra of Rh6G absorbed by silver nanofluid showed strong enhancement of Raman bands 1175cm^-1 and 1529cm^-1, 1590 cm^-1. Those correspond to vibrational frequency modes – υ₁₀₃,υ₁₅₁,₁₅₂. We also measured the Raman spectra of e-coli bacteria, both absorbed by silver nanofluid, and on nanostructured substrate. In addition, the Fourier Transfer Infrared Spectra (FTIR) of the bacteria was measured.

The Raman signal of inelastically scattered photons represents the fingerprint of a chemical molecule. Therefore, surface enhanced Raman spectroscopy (SERS) can be employed as the selective mechanism for an extraordinary optics sensor sensitive enough to detect a single molecule. Such sensitivity makes SERS ideal to detect chemicals at parts per billion to parts per trillion concentrations. SERS studies benefit from a signal enhancing substrate that is both reproducible and cost effective. Commercial substrates produced by electron beam lithography cost approximately $100 a piece to manufacture and can only be used once. The purpose of this study is to design a SERS substrate that offers enhancement equivalent to the commercial standard and is cheaper to produce. Experiments confirm that gold (Au) coated nano-pores can be used as an optimal SERS substrate offering a promising enhancement with durability that rival commercial products.

Second harmonic generation (SHG) laser spectroscopy has been demonstrated to be a powerful, sensitive, and non-destructive analytical technique to study crystalline phases, domain structures, and molecular dipole orientations of ferroelectric polymeric thin films such as PVDF. While other spectroscopic techniques, such as WXRD and FTIR, do provide valuable information on the crystalline phases, they are not sensitive enough to provide the detailed information at molecular levels and properties at interfaces. The current study of single layered PVDF polymer has also shown that SHG can be further developed into an in-situ, sensitive and quantitative tool to study ferroelectric polymeric thin film structures. In combination, SHG and electric field induced SHG (EFISH) techniques will allow us to interrogate multilayered structures layer-by-layer, the effects of physical confinement and interfacial physics.

Sculptured thin films (STFs) are columnar thin films nano-engineered to have controllable porosity, structural chirality and periodicity in one, two or three dimensions. These characteristics of STFs have been exploited in developing optical elements such as thin film filters, polarizers, sensors, and waveguides for integrated optics. They can be fabricated by a simple two-stage (lithography and deposition) process. In this paper, we develop a grating theory-based modeling approach for STFs as fully 3D periodic structures. Input for this model consists of a structural parameter set that is easily accessible experimentally. This helps establish a common parameter set for evaluating STFs from a fabrication as well as modeling perspective, thus laying the base required for developing appropriate process monitoring and control methods necessary for successful commercial production. Using the proposed model, we develop a quantitative understanding of the limits of applicability of traditional modeling methods for STFs and develop guidelines for robust design of STF-based devices. We apply this knowledge gained to explore STFs in two illustrative examples: (i) as a notch filter, and (ii) as a 3D photonic crystal. The results demonstrate the potential for success and highlight the remaining challenges that need to be overcome.

Chiral sculptured thin films (CSTFs) are well-suited to optical-sensing applications because their multiscale porosity and optical properties can be tailored to order. Two independent modalities of optical sensing were considered. For both modalities, the analytes to be sensed are assumed to fully penetrate the void regions of the CSTF and thereby give rise to measurable changes in the macroscopic optical responses of the CSTF. The first modality is based on the excitation of multiple surface-plasmon-polariton (SPP) waves at the planar interface of a CSTF and a metal film, while the second is based on the spectral shift in the circular Bragg phenomenon (CBP). We considered a CSTF with a central twist defect of 90^°. Our numerical studies revealed a CSTF coated with a thin layer of metal of appropriate thickness can simultaneously support the excitation of multiple SPP waves and the CBP, with both phenomenons being independently sensitive to the refractive index of a fluid which infiltrates the void regions of the CSTF. Accordingly, an integrated dual-modality optical sensor may be envisaged which harnesses both modalities of sensing simultaneously. Such an optical sensor offers the potential to detect more than one type of analyte at a time, with increased sensitivities and/or specificities.

Even prior to the recent advent of advanced top-down processes, shadowing growth by oblique angle deposition (OAD) has long been providing self-assembled nanostructures over much larger areas for much lower costs. In the past two decades, significant progress has been made in the development of well-controlled three-dimensional nanomorphologies such as zigzags and helixes. Much effort has been put into theoretical and numerical understanding of the growth mechanism to improve morphology. Many researchers in academia have been investigating useful properties of nanocolumnar thin films in their laboratories. However, most companies seem hesitant to introduce OAD techniques into the factory owing to the prejudice that the OAD thin films are neither durable nor reproducible. In this review article, we discuss the progress in OAD technology for practical applications.

Optical quality PMMA thin film layers including different concentrations of 3nm CdSe/ZnS and 5 nm TiO2 semiconductor quantum dots have been made by spin coating method. Their optical properties show evident consequences of the confinement effects with wavelength bandgap shifting for both types of QDs. The confinement effects are more pronounced for CdSe/ZnS QDs than for TiO2 QDs. Layers including CdSe/ZnS QDs exhibit a strong luminescent behavior centred on 560nm with a stock-shift in front of the first exciton absorption peak.

We excited multiple surface-plasmon-polariton (SPP) waves guided by the interface of a metal and a chiral sculptured thin film (STF). Chiral STFs made by thermally evaporating NaF and either 3, 4, or 5 periods in thickness were deposited on a metal film by oblique angle deposition accompanied by substrate rotation, each period being 300 nm, for plasmonic investigations in the Turbadar-Kretschmann-Raether (TKR) configuration. Reflectances were measured for a range of incidence angles for both p- and s-polarization states of the incident monochromatic light. Several reflectance minimums independent of the thickness of the chiral STF were obtained, indicating that multiple SPP waves had been excited.

Chiral sculptured thin films (STFs) produced by substrate rotation during physical vapor deposition exhibit the circular Bragg phenomenon, whereby normally incident left- and right-circularly polarized plane waves are discriminated in a spectral regime called the circular Bragg regime. Theory had predicted that substrate rocking, in synchrony with substrate rotation, during deposition, could suppress the propensity to exhibit the circular Bragg phenomenon. Therefore, ZnSe chiral STFs were fabricated with/without substrate rocking, and their transmittance spectrums for incident linearly and circularly polarized plane waves were measured. With sufficient rocking amplitude, the discrimination between incident left- and right-circularly polarized light nearly vanished, whereas a Bragg phenomenon for all normally incident plane waves was observed. Thus, chiral STF technology can be used to produce both ordinary and circular-polarization Bragg filters.

Thermophotovoltaic power generation has recently attracted considerable attention as a means to use waste heat. In order to improve the efficiency of TPV power generation, it is necessary to develop spectrally and directionally selective thermal emitters. By taking advantage of high refractive index of β-FeSi2 (n ∼ 5), we have successfully demonstrated that the spectrally selective emitter is fabricated by sputtering a β-FeSi2 thin film on a polished 304 stainless steel substrate. A noble bottom up process to fabricate periodic array of β-FeSi2 nanopillars, which are necessary for the directionally selective emission, will be also presented.

We considered a porous thin film as a platform for optical sensing. It is envisaged that the porous thin film becomes infiltrated by a fluid containing an agent to be sensed. The basis for detection of this agent to be sensed is provided by changes in the optical properties of the infiltrated porous thin film. Provided that the pore sizes are much smaller than the wavelengths involved, the infiltrated porous thin film may be regarded as a homogenized composite material. Using the well-established Bruggeman homogenization formalism, the sensitivity of such an optical sensor was investigated theoretically. The sensitivity was considered in relation to the optical properties of the porous thin film and the infiltrating fluid, the porosity of the thin film, and the shape of the pores. For the case of an isotropic dielectric porous thin film of relative permittivity < a and an isotropic dielectric fluid of relative permittivity <b, the sensitivity was found to be maximized if: (i) the contrast between <a and <b was maximized; (ii) mid-range values of porosity were used; (iii) the regime 0 < <b < 1 with <a < 1 pertained, for example; and (iv) pores which have elongated spheroidal shapes were incorporated.

Optical properties and effective dielectric function of nanostructured materials consisting of silver nanoparticles embed in dielectric matrix were studied. Experimental part was performed by means of angular and spectroscopic ellipsometry. Measured angular dependences reveal, that optical conductivity changes from metallic to dielectric with decrease of silver volume fraction. Complex effective dielectric function of the samples was measured within 295-825 nm wavelength range. Dispersion of optical constants of the samples with high silver volume fractions f<0.53 appears to be qualitatively similar to bulk silver. With decrease of Ag concentration influence of plasmon resonance on optical properties of the samples is observed. Measured spectral dependences reveal redshift and significant broadening of plasmon resonance peak of sample with f=0.28 in comparison to those with f=0.06-0.15 which can be explained within framework of surface plasmon resonance theory. Calculations show, that experimental data can’t be described using standard Maxwell-Garnett and Bruggeman effective-medium theories. Effective dielectric function of such composite films can be tuned by varying silver concentration, size and shape of the metal particles. We show that measured values of complex index of refraction for samples with f=0.08-0.2 can guarantee a strong light absorption for 400 nm film thickness according to Fresnel equations and demonstrate, that a considerable fraction of light can be trapped in the film due to total internal reflection of the light, scattered by noble metal nanoparticles.

A structurally right-handed chiral sculptured thin film (STF) with a central 90º-twist defect was made by thermal evaporation of chalcogenide glass and the use of a serial bi-deposition process to exhibit a narrowband hole in the spectrum of the right-circularly polarized light reflected when right-circularly polarized light is normally incident on the chiral STF. The chiral STF was then infiltrated with a highly birefringent nematic liquid crystal (LC), which caused a linear reflectance peak to redshift by ~350 nm, but the circular Bragg phenomenon exhibited by the uninfiltrated chiral STF was greatly diminished owing to the similarity in the constitutive properties of the LC and the chalcogenide glass. No temperature dependence of the shifted peak was observed, which provided clear evidence that the LC molecules are not ordered inside the chiral STF but are randomly aligned instead.