Oxidised porous silicon/disperse red 1 composite material: fabrication and micro‐Raman spectrometry analysis

Abstract

PACS Single porous silicon layers (60%, 70% and 80% porosity) and double porous silicon layers with two different porosities (80%-73% and 73%-80%) were completely oxidised and then filled by Disperse Red One molecules (referred to as DR1). The formed composite materials were characterised by optical reflectivity measurements and micro-Raman spectrometry in order to probe the DR1 relative concentration profile along the porous layers. In the single layers, the Raman signals linearly increase with porosity starting from a critical value (estimated at 40% before oxidation). On the contrary, in the case of double layer systems, the DR1 filling was always higher in the low porosity layer.

Porous silica composite material for non‐linear optical properties: characterisation by spectroscopic ellipsometry and second harmonic generation

“…Then, the solution was introduced into the oxidised porous silicon films with a micro-syringe. Uniform distribution of the filling of the porous silicon films by the organic molecules (DR1), from the surface up to the silicon interface, was demonstrated by micro-Raman analysis [5,6], and a concentration about 4% was found [7]. The poling process was carried out by a static electric field of 1000 Volts, applied between two flat electrodes (?…”

Protic Properties of Water Confined in the Pores of Oxidized Porous Silicon Studied by Excited-State Proton Transfer from a Photoacid

“…The pore density remains the same, but the pore size decreases, so the porosity after oxidation becomes lower than the porosity before oxidation. The pore shape is conserved in spite of size reduction of the pore size, as the increase is due to the volume expansion of silicon transformed into oxidized silicon. , The refractive index is also affected by oxidation, it decreases after the oxidation. If PSi is fully oxidized then its refractive index value is between that of air ( n = 1) and that of silicon ( n = 1.46), depending on its porosity.…”

Vibrational analysis of [4-[(E)-phenylazo] phenyl]ethanol based on the comparison between the experimental and DFT calculated Raman spectra

“…Because of their unique characteristics [1] (spread over air-water interface [2,3], disperse into porous materials to form hybrid organic-inorganic composites [4][5][6], graft onto polymers chains [7][8][9] or onto inorganic materials and surfaces [10][11][12][13]) azobenzene and its derivatives have been of great interest over the past two decades. The azobenzene derivatives which exhibit photoisomerization from the thermodynamically more stable trans isomer to the cis isomer (and vice versa) by irradiation with UV or visible light were extensively studied for their photochemical properties in solution [1,14] and therefore for their ability to produce photochemical devices [16][17][18].…”