The present work reports the thermal annealing process, number of layer and electrochemical process effect in optical response quality Bragg microcavity devices that were applied as organic solvent sensors. These have been obtained by using porous silicon (PS) technology. characterization reflector, before annealing, showed a broad photonic band-gap structure with blue shifted narrowed after process. used to obtain PS-based device imposes limit layers because chemical dissolution effect....

Using electromagnetic modeling and analytical methods, we study the optimal conditions of an enantioselective optical process (EOP) through interaction potential between enantiomers localized chiral near-fields created by asymmetric plasmonic crescent moon (PCM) nanoapertures when it is illuminated with circularly polarized light. We introduce a dissymmetry factor which measures degree discrimination EOP found that depends mainly on differential field intensification, near-field chirality...

The present work reports the porous alumina structures fabrication and their quantitative structural characteristics study based on mathematical morphology analysis by using SEM images. algorithm used in this was implemented 6.2 MATLAB software. Using it possible to obtain distribution of maximum, minimum average radius pores structures. Additionally, with calculus area occupied pores, porosity results could be obtained related process characteristics, showing reliable promising control...

This work deals with a portable device system applied to detect and classify different metallic ions as proposed developed, aiming its application for hydrological monitoring systems such rivers, lakes groundwater. Considering the features, colorimetric was developed by using multispectral optoelectronic sensor. All technology of quantification classification sensors fully integrated in embedded hardware FPGA ( Field Programmable Gate Array) software based on virtual instrumentation (NI...

The surface plasmons that are enabled by grating coupling in two-dimensional gold nano-particle arrays (AuNPAs) affected the spectral characteristics of up-conversion (UC) emission from Yb(3+)-Er(3+)-Gd(3+) co-doped sodium yttrium fluoride (NaYF4:Yb/Er/Gd) nano-rods. red NaYF4:Yb/Er/Gd nano-rods at 660 nm (excited with a 980 diode laser) was significantly enhanced interaction AuNPAs. geometric nanoparticles influenced position plasmon resonance, and their near field strengths. intensity...

In this paper, we report the results of investigation about optical properties one-dimensional photonic crystals based on porous silicon multilayer structures having unit cells with that vary as a function device thickness. These devices were obtained by anodizing crystalline in electrolyte aqueous solution HF at different concentrations. The effective refractive index and extinction coefficients, layers had been fitting experimental reflectance spectra using transfer matrix method....

Enhanced upconversion (UC) emission was experimentally demonstrated using gold double antenna nanoparticles coupled to nanoslits in films.

The present work reports on the effect of type backside contact used in electrochemical process and their relation with structural features optical responses one-dimensional photonic crystal (PC) anodized simple double cell. PC, obtained single cell, showed to have thicker layers than PC Additionally, cell highest reflectance band gap region PCs These results suggest that interface roughness between adjacent devices is minimized.

The present work reports the two types of silicon nanotubes fabrication. tubular structures based on have been fabricated by immersing mesoporous layer into aqueous electrolyte a mixture NH 4 F and NiSO . Similar results are achieved that was formed from wafer previously metallized its smooth surface with aluminum after annealing in N 2 environment. In this case, either or nickel can easily be only tuning pH level ammonium fluoride solution. range inner diameter these tubes varies 40 to 110...

A porous silicon lm (PS) was investigated by FTIR, Raman and photoluminescence (PL) spectroscopies. The PL spectra were obtained using four different laser excitations: 488, 514, 633 782 nm. analysis of the first order second scattering lines permits to identify band energy structure crystallites inside PS film. shows that intensity full width at half-maximum values emission depends on excitation. linear polarization degree (LPD) also presents a dependence observed due excitation cannot be...

Abstract Porous silicon (PS) films were investigated by Raman, and photoluminescence spectroscopies using different laser excitations at 488.0, 514.5, 632.8, 782.0 nm. The exposure of PS layers to high powers causes an increase in the 480 cm −1 Raman intensity a shift enhancement PL emission. A laser‐assisted surface reaction is proposed explain these observations. analysis first‐ second‐order spectra showed that band gaps are indirect as bulk c‐Si. phonon also spectral distribution linear...

In this paper, it is presented a new temperature sensor designed for self-protection of Integrated Circuits (IC). This mainly prevents damages caused by heating which can lead to burning or malfunctioning electronic devices. The main objective create small-area low-power consumption protection circuit that operates independently an external circuitry and self-protects the IC against heating, in range -20°C 120°C. was using Cadence Virtuoso employing System on Chip (SoC) concept, standard...

The effect of different polarization orientations the excitation source on Raman and photoluminescence (PL) spectra a porous silicon (PS) layer within two micro-regions was investigated. Two (2 μm) along (100) direction were studied, close to crystalline (c-Si)–PS interface PS layer–air interface. depolarization factors obtained in 100–1200 cm -1 phonon these showed that anisotropy presented by is similar c-Si (100). Large differences linewidths emission maxima PL observed for micro-regions....

Abstract The present work reports the formation of self-assembled systems by chemical and electrochemical techniques for photonic crystal structures fabrication. technique was used to fabrication polystyrene micro-spheres structures. influence temperature setup monodispersion concentration in self-assemble mechanism studied. also fabricate porous alumina electrolyte type anodic voltage process were analyzed possibility application as