INVESTIGATIONS ON AZO/Al/AZO MULTILAYER STRUCTURE GROWN AT ROOM TEMPERATURE

2018 ◽  
Vol 25 (08) ◽  
pp. 1950033
Author(s):  
SAAD AMARA ◽  
MOHAMED BOUAFIA

In this work we investigate the effect of metal layer in the Al-doped ZnO (AZO)/Al/AZO structure. AZO and Al thin films are deposed successively at room temperature using DC magnetron sputtering by rotating the substrate holder without breaking the vacuum. The optical characterization of AZO/Al/AZO structure was performed by the spectroscopic ellipsometry under different incidence angles (55[Formula: see text], 65[Formula: see text] and 75[Formula: see text]). For the AZO monolayer structure, it was found that the complex refractive index and the complex permittivity coefficient varied differently according to the incidence angle. The addition of Al layer (5[Formula: see text]nm thicknesses) in this monostructure reduces significantly this influence on the measurement, homogenizes the real refractive index variation and significantly reduces the real electrical coefficient permittivity in the visible range. In addition, the obtained depolarization values confirm the results of the AFM roughness revealing that the Al layer addition makes the surface smoother so that it meets the required conditions as the bottom electrode of organic light emitting diodes. The photoluminescence (PL) measurements indicate that the Al layer alters the PL emission. Actually, the Al layer enhances subsequently the PL emission and promotes the blue and red emission.

2019 ◽  
Vol 629 ◽  
pp. A112 ◽  
Author(s):  
B. M. Giuliano ◽  
A. A. Gavdush ◽  
B. Müller ◽  
K. I. Zaytsev ◽  
T. Grassi ◽  
...  

Context. Reliable, directly measured optical properties of astrophysical ice analogues in the infrared and terahertz (THz) range are missing from the literature. These parameters are of great importance to model the dust continuum radiative transfer in dense and cold regions, where thick ice mantles are present, and are necessary for the interpretation of future observations planned in the far-infrared region. Aims. Coherent THz radiation allows for direct measurement of the complex dielectric function (refractive index) of astrophysically relevant ice species in the THz range. Methods. We recorded the time-domain waveforms and the frequency-domain spectra of reference samples of CO ice, deposited at a temperature of 28.5 K and annealed to 33 K at different thicknesses. We developed a new algorithm to reconstruct the real and imaginary parts of the refractive index from the time-domain THz data. Results. The complex refractive index in the wavelength range 1 mm–150 μm (0.3–2.0 THz) was determined for the studied ice samples, and this index was compared with available data found in the literature. Conclusions. The developed algorithm of reconstructing the real and imaginary parts of the refractive index from the time-domain THz data enables us, for the first time, to determine the optical properties of astrophysical ice analogues without using the Kramers–Kronig relations. The obtained data provide a benchmark to interpret the observational data from current ground-based facilities as well as future space telescope missions, and we used these data to estimate the opacities of the dust grains in presence of CO ice mantles.


2000 ◽  
Vol 5 (S1) ◽  
pp. 412-424
Author(s):  
Jung Han ◽  
Jeffrey J. Figiel ◽  
Gary A. Petersen ◽  
Samuel M. Myers ◽  
Mary H. Crawford ◽  
...  

We report the growth and characterization of quaternary AlGaInN. A combination of photoluminescence (PL), high-resolution x-ray diffraction (XRD), and Rutherford backscattering spectrometry (RBS) characterizations enables us to explore the contours of constant- PL peak energy and lattice parameter as functions of the quaternary compositions. The observation of room temperature PL emission at 351nm (with 20% Al and 5% In) renders initial evidence that the quaternary could be used to provide confinement for GaInN (and possibly GaN). AlGaInN/GaInN MQW heterostructures have been grown; both XRD and PL measurements suggest the possibility of incorporating this quaternary into optoelectronic devices.


2021 ◽  
Author(s):  
Rahma Ben Said ◽  
N. Moutia ◽  
B. Louati ◽  
K. Guidara ◽  
K. Khirouni

Abstract New Zn2P2O7, K2ZnP2O7 and KZn1.5P2O7 compounds were synthesized with conventional solid solid reaction method. The optical properties have been studied by using UV-Visible spectrophotometer. The optical band gaps (Eg) were found to be 3.76 eV, 3.39 eV and 3.59eV respectively. Optical parameters such as refractive index, Cauchy’s parameters and conductivity were deduced. The refractive index fitting in the visible range and the dispersion parameters (E0 and Ed) of these compounds were estimated using the Wemple–DiDomenico model.


1999 ◽  
Vol 595 ◽  
Author(s):  
Jung Han ◽  
Jeffrey J. Figiel ◽  
Gary A. Petersen ◽  
Samuel M. Myers ◽  
Mary H. Crawford ◽  
...  

AbstractWe report the growth and characterization of quaternary AlGaInN. A combination of photoluminescence (PL), high-resolution x-ray diffraction (XRD), and Rutherford backscattering spectrometry (RBS) characterizations enables us to explore the contours of constant- PL peak energy and lattice parameter as functions of the quaternary compositions. The observation of room temperature PL emission at 351nm (with 20% Al and 5% In) renders initial evidence that the quaternary could be used to provide confinement for GaInN (and possibly GaN). AlGaInN/GaInN MQW heterostructures have been grown; both XRD and PL measurements suggest the possibility of incorporating this quaternary into optoelectronic devices.


2021 ◽  
Vol 8 (1) ◽  
pp. 31
Author(s):  
Sarla Yadav ◽  
Sumit Kumar Mishra

Modelling the optical and radiative properties of atmospheric particles is governed by one of the key input parameters, i.e., the refractive index of aerosols. Availability of the region-specific refractive index data of aerosols is a major challenge for the atmospheric community. The refractive index of aerosols is a function of their physico-chemical properties. Uncertainty in the computation of the spectral refractive indices of aerosols leads to erroneous assessment of their optical and radiative properties. In the present work, the refractive indices of pure clay (kaolinite, illite) and polluted clay with anthropogenic hematite, AH (0.10 to 1.48%) submicron particles have been computed for the wavelength range of 0.38 to 1.2 µm. Anthropogenic hematite enhanced the overall absorption in the UV and visible range with maximum absorption at lower wavelengths (less than 0.55 µm).


2016 ◽  
Vol 851 ◽  
pp. 199-204 ◽  
Author(s):  
Veronika Schmiedova ◽  
Jan Pospisil ◽  
Oldrich Zmeskal ◽  
Viliam Vretenar

The paper deals with the study of optical properties of graphene oxide (GO) by inkjet printing. Defined structure of GO can be obtained by reducing of prepared layers either by heating or by UV radiation (rGO). The dispersion function for refractive index and extinction coefficient of GO and both rGO thin films were measured by spectroscopic ellipsometry in the wavelength range of 200 – 850 nm. Spectroscopic ellipsometry (SE) was used characterize the optical response of layer of GO reduced by UV and thermal reduction GO in visible range.


2005 ◽  
Vol 277-279 ◽  
pp. 1006-1010
Author(s):  
Seung Hee Lee ◽  
Won Hee Han ◽  
Hyun Seo Shin ◽  
Sang Jin Lee

The synthesis and characterization of a series of square planar Pt(II) complexes, which are luminescent at room temperature, are reported. The complexes have the general structure of (C^N)Pt(O^O), where HC^N is 3-phenylpyridazine (ppdz), 3-(4’-biphenyl)pyridazine (4’phppdz), 3-(2’-naphthyl)pyridazine (2’napdz), or 3-(1’-naphthyl)pyridazine (1’napdz), and HO^O is acetylacetone (Hacac). The reaction of K2PtCl4 with HC^N forms the chloro-bridged dimer, (C^N)Pt( µ-Cl)2Pt(C^N), which are cleaved with an ancillary ligand to give the corresponding monomeric (C^N)Pt(O^O) complexes. The emission bands of these complexes are governed by the structure of the cyclometalating ligands, with emission band (lem) ranging from 516 to 645 nm. The two emission bands at (515 and 550 nm) of (ppdz)Pt(acac) complex have 7 and 6 ms of life time which imply those bands are due to phosphorescence decay. The conjugating ring on the pyridazine makes the emission more red shifted which is expected based on molecular orbital calculation. In addition to the alteration of cyclometalating ligands, ancillary ligands also change. These results can be compared with the corresponding Ir(III) complexes.


2018 ◽  
Vol 185 ◽  
pp. 09007
Author(s):  
Constantine Yerin ◽  
Victoria Lykhmanova ◽  
Marina Erina

The spectra of the real and imaginary parts of the refractive index of magnetic fluids based on kerosene with a solids phase concentration of 1% to 35% are experimentally measured. The comparison of calculations results have been made according to Maxwell-Garnett and Bruggeman’s models of effective medium approximation. The influence of refractive index spectra on the extinction of light in magnetic fluids is shown.


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