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Effect of substrate temperature on the optical and structural properties of CdS nano particles

Qassim Barzan Kh., Uonis Mohammad M., Khaleel Erada A.

Ochrona przed Korozją

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2023

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nr 11

354--357

EN

Thin films of CdS have been deposited on glass substrates using the chemical spray pyrolysis method at different substrate temperatures of 100°C, 150°C, 200°C, and 250°C to investigate the optimum temperature to prepare CdS particles with nano dimensions. The CdS thin film was examined using SEM, X-ray spectrum analysis, and UV-visible spectrophotometry. The SEM images and X-ray spectra were used to estimate the structural features and grain size of the films. The optical properties and optical constants also varied clearly with temperature. In addition, the energy gap changed with temperature from 2.1 eV to 2.55 eV.

PL

Wpływ temperatury podłoża na właściwości optyczne i strukturalne nanocząstek CdS Cienkie warstwy CdS zostały osadzone na szklanych podłożach metodą chemicznej pirolizy natryskowej w temperaturach podłoża wynoszących 100°C, 150°C, 200°C i 250°C w celu określenia optymalnej temperatury do przygotowania cząstek CdS o wymiarach nano. Tak przygotowane próbki zostały zbadane za pomocą SEM i spektrofotometrii UV-VIS, przeprowadzono także analizę widma rentgenowskiego. Obrazy SEM i widma rentgenowskie zostały wykorzystane do oszacowania cech strukturalnych i wielkości ziarna warstw. Właściwości optyczne i stałe optyczne zmieniały się wyraźnie wraz ze zmianą temperatury. Przerwa energetyczna wynosiła w zależności od temperatury od 2,1 eV do 2,55 eV.

2

Fabrication, characterization and photocatalytic properties of CdS nanoparticles modiﬁed by N-doped TiO2 NTs

Gao D., Wang C., Jian Y., Li W., Dong P.

Materials Science Poland

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2018

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Vol. 36, No. 3

348--353

EN

Highly ordered TiO2 nanotube arrays (TiO2 NTs) were prepared by anodic oxidizing method on a surface of Ti substrate. Fabrication of nitrogen-doped TiO2 nanotube arrays (N-TiO2 NTs) was carried out by immersion in ammonia solution. CdS nanoparticles loaded N-doped TiO2 nanotube arrays (CdS/N-TiO2 NTs) were obtained by successive ionic layer adsorption and reaction (SILAR) technique. The samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), photoluminescence (PL) emission spectra and ultraviolet-visible (UV-Vis) diffuse reflectance spectroscopy (DRS). The results indicate that the TiO2 nanotube diameter and wall thickness are 100 nm to 120 nm and 20 nm to 30 nm, respectively. Moreover, the morphology and structure of the highly ordered TiO2 NTs are not affected by N-doping. Furthermore, CdS nanoparticles are evenly distributed on the surface of TiO2 NTs. Finally, the photocatalytic activity of CdS/N-TiO2 NTs was evaluated by degradation of MO under visible-light irradiation. Compared with TiO2 NTs, N-TiO2 NTs, CdS/N-TiO2 NTs exhibited enhanced photocatalytic properties, and the highest degradation rate of CdS/N-TiO2NTs could reach 97.6 % after 90 min of irradiation.

3

Stable phase CdS nanoparticles for optoelectronics: a study on surface morphology, structural and optical characterization

Kumar S., Sharma J. K.

Materials Science Poland

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2016

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Vol. 34, No. 2

368--373

EN

This work presents a study on the surface morphology, structure and optical behavior of stable phase cadmium sulphide (CdS) nanoparticles synthesized via co-precipitation technique. Scanning electron microscopy (SEM) analysis has been employed to study a cluster formation in the aggregated nanoparticles. An image analysis approach using ImageJ has been used to measure the size of nanoparticles from the SEM micrographs. Fourier transform infrared spectroscopic (FT-IR) analysis identified absorption peaks of Cd–S stretching along with moisture content. X-ray diffraction (XRD) analysis showed that CdS nanoparticles crystallized in wurtzite structure with a preferential orientation along (0 0 2) plane. The particle size, microstrain and lattice constants have been evaluated using XRD data. The lattice parameters of these nanoparticles were found to be shorter than the bulk value which led to lattice contraction. The optical absorption study showed a blue shift in the fundamental absorption edge indicating a quantum size effect.

4

Linear and nonlinear optical spectroscopy of CdS nanoparticles in Nafion membranes

Bourdin E., Henari F.Z., Blau W.J., Kelly J.M.

Journal of Telecommunications and Information Technology

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2000

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nr 1-2

29-36

EN

CdS nanoparticles embedded in Nafion membranes were studied by a variety of optical spectroscopic methods. Quantum confinement was achieved (particle mean diameter of 40 A) and the growth was found to follow a linear temporal kinetic law. Discrete energy levels were observable, even at room temperature. They could be attributed to light hole and heavy hole IS and 2S transitions. The experimental results are in good agreement with theoretical calculations of light hole and heavy hole masses in the cases of cubic CdS. An enhancement of the nonlinear susceptibility chi(3) at the quantized exciton energy levels was observed. The clusters were found to be photo-unstable, with a diffusion-limited growth rate due to Ostwald ripening.