Synthesis and Characterization of Mn2+ Doped ZnS Using Reverse Miceller Method

2014 ◽  
Vol 970 ◽  
pp. 283-287
Author(s):  
Rahizana Mohd Ibrahim ◽  
Markom Masturah ◽  
Huda Abdullah
Keyword(s):  
Quantum Confinement ◽  
Quantum Confinement Effect ◽  
Blue Shift ◽  
Band Gap Energy ◽  
Confinement Effect ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Size Of Particles ◽  
Absorbance Spectra

In this work we synthesized the monodisperse of Zn1-xMnxS with x =0.00,0.02,0.04,0.06,0.08 and 0.10 nanoparticles by reverse micelle method using sodium bis (2-ethylhexyl) sulfosuccinate (AOT) as surfactant. The prepared particles were characterized using UV-Visible Spectroscopy, X-ray diffraction (XRD), Transmission Electron Microscopy (TEM) and Photoluminescence (PL) for size, morphology and optical of the samples .UV-vis absorbance spectra for all of the synthesized nanoparticles show the maximum absorption for all samples is observed at range 210 - 300 nm . The absorption edge shifted to lower wavelengths when doping with ion Mn as per UV-Vis spectroscopy. The band gap energy values were increase from 4.50eV to 4.90 eV. This blue shift is attributed to the quantum confinement effect. The size of particles is found to be 3-5nm range. The Mn2+ doped ZnS nanoparticles using reverse micelles method shows the enhance of PL intensity results in monodisperse nanoparticles. Keywords: Nanoparticles; UV-vis absorbance spectra; quantum confinement effect; photoluminescence.

Synthesis of Fe2+ Ion Doped ZnS Nanoparticles

2014 ◽  
Vol 879 ◽  
pp. 155-163 ◽  
Author(s):  
Rahizana Mohd Ibrahim ◽  
Markom Masturah ◽  
Huda Abdullah
Keyword(s):  
Electron Microscopy ◽  
Optical Properties ◽  
Quantum Confinement Effect ◽  
Band Gap Energy ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Co Precipitation

Nanoparticles of Zn1-xFexS ( x=0.0,0.1,0.2 and 0.3) were prepared by chemical co-precipitation method from homogenous solution of zinc and ferum salt at room temperature with controlled parameter. These nanoparticles were sterically stabilized using Sodium Hexamethaphospate (SHMP). Here, a study of the effect of Fe doping on structure, morphological and optical properties of nanoparticles was undertaken. Elemental analysis, morphological and optical properties have been investigated by Fourier-Transform-Infrared spectroscopy (FT-IR), X-Ray Fluorescence (XRF), Field Emmision Scanning Electron Microscopy (FESEM), X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and UV-Visible Spectroscopy. FTIR measurement confirmed the presence of SHMP in the nanoparticles structure with the FESEM images depicting considerable less agglomeration of particles with the presence of SHMP. While XRF results confirm the presence of Fe2+ ion as prepared in the experiment. The particles sizes of the nanoparticles lay in the range of 2-10 nm obtained from the TEM image were in agreement with the XRD results. The absorption edge shifted to lower wavelengths with an increase in Fe concentration shown in the UV-Vis spectroscopy. The band gap energy value was in the range of 4.95 5.15 eV. The blueshift is attributed to the quantum confinement effect.

[ZnSe(dbn)1/2] and [ZnSe(hda)1/2]: Two New Members of Inorganic-Organic Hybrid Semiconductor Nanocomposites Exhibiting A Strong Quantum Confinement Effect

2002 ◽  
Vol 728 ◽  
Author(s):  
Xiaoying Huang ◽  
Jing Li
Keyword(s):  
Quantum Confinement ◽  
Quantum Confinement Effect ◽  
Diffraction Method ◽  
Blue Shift ◽  
Confinement Effect ◽  
X Ray Diffraction ◽  
Orthorhombic Crystal ◽  
New Members ◽  
Organic Hybrid ◽  
Semiconductor Nanocomposites

AbstractTwo new inorganic-organic hybrid II-VI semiconductor nanostructures have been synthesized by solvothermal reactions. These nanostructures consist of inorganic 2∞[ZnSe] layers and organic bridging diamine molecules as spacers. The crystal structures of [ZnSe(dbn)1/2](1, dbn = 1,4-diaminobutane) and [ZnSe(hda)1/2](2, hda = 1,6-hexanediamine) have been determined by the powder X-ray diffraction method. They are isostructural and crystallize in the orthorhombic crystal system, space group Pbca(No.62), Z = 4. Crystal data for 1: a = 6.646(3), b = 6.473(3), c = 22.31(1) Å, V = 961.2(13) Å3, for 2: a = 6.6252(18), b = 6.4505(17), c = 27.138(7) Å, V = 1159.8(9) Å3. The optical absorption experiments show that both 1 and 2 generate a very large blue shift in the absorption edge (1.5-1.6 eV) due to a strong quantum confinement effect (QCE). Thermogravimetric behavior of both compounds has also been investigated.

CdS/Cyclohexylamine Inorganic–Organic Hybrid Semiconductor Nanofibers with Strong Quantum Confinement Effect

2008 ◽  
Vol 8 (8) ◽  
pp. 3914-3920 ◽  
Author(s):  
Libo Fan ◽  
Hongwei Song ◽  
Haifeng Zhao ◽  
Guohui Pan ◽  
Lina Liu ◽  
...  
Keyword(s):  
Quantum Confinement ◽  
Quantum Confinement Effect ◽  
Blue Shift ◽  
Average Diameter ◽  
Confinement Effect ◽  
Dimethyl Formamide ◽  
Organic Hybrid ◽  
Cds Nanorods ◽  
Transmission Electron ◽  
20 Nm

Inorganic–organic hybrid semiconductor nanofibers of CdS/CHA (CHA = cyclohexylamine) were successfully synthesized by a simple solvothermal method. The fibers obtained had average diameter of 20 nm and length of several micrometers. In these fibers, periodic layer-like sub-nanometer structures with thickness of ∼3 nm were identified by high-resolution transmission electron microscope (HR-TEM). The absorption of the hybrids exhibited a large blue-shift in contrast to the bulk, which was attributed to strong quantum confinement effect (QCE) induced by internal sub-nanometer structures. Pure hexagonal wurtzite CdS (H-CdS) nanorods were also obtained by extracting the CdS/CHA hybrids with dimethyl formamide (DMF). The rods obtained had average diameter of 20 nm and length of 200 nm. A CdS/CHA/polyvinyl alcohol (PVA) composite film emitting white light was prepared by spin coating.

Opto-Electronic Properties of Green Synthesized ZnS Nanostructures

2018 ◽  
Vol 17 (04) ◽  
pp. 1760032
Author(s):  
Sujata Deb ◽  
P. K. Kalita ◽  
P. Datta
Keyword(s):  
Quantum Confinement ◽  
Quantum Confinement Effect ◽  
Blue Shift ◽  
Cubic Phase ◽  
Capping Agent ◽  
X Ray Diffraction ◽  
Chemical Route ◽  
Transmission Electron ◽  
Wet Chemical ◽  
Green Capping Agent

ZnS nanostructures are synthesized by a wet chemical route using starch as green capping agent under nitrogen environment. The as-prepared nanostructures are characterized structurally, optically and electrically. X-ray diffraction (XRD) spectra confirm that the zinc sulfide (ZnS) nanoparticles have cubic phase (zinc blende). UV–Vis spectrum of the sample clearly shows that the absorption peak exhibits blue shift compared to their bulk counterpart, which confirms the quantum confinement effect of the nanostructures. Its photoluminescence (PL) spectrum shows near band gap emission at 392[Formula: see text]nm and extrinsic emission at 467[Formula: see text]nm. The particle sizes calculated from XRD and UV studies are in fair agreement with high resolution transmission electron microscopy (HRTEM) results. Starch is found to be a noble capping agent in bringing quantum confinement. The synthesis under nitrogen environment has been observed to produce quality products by reducing the oxide traces. Moreover, the I–V characteristics under dark and illumination show that ZnS can be more suitable as photodetector.

QUANTUM CONFINEMENT EFFECT IN HgTe NANOCRYSTALS AND VISIBLE LUMINESCENCE

2004 ◽  
Vol 03 (03) ◽  
pp. 393-401 ◽  
Author(s):  
S. RATH ◽  
A. K. DASH ◽  
S. N. SAHU ◽  
S. NOZAKI
Keyword(s):  
Valence Band ◽  
Quantum Confinement ◽  
Quantum Confinement Effect ◽  
Free Exciton ◽  
Confinement Effect ◽  
Electrochemical Technique ◽  
Cubic Phase ◽  
Exciton Transition ◽  
Mercury Telluride ◽  
Transmission Electron

Mercury Telluride ( HgTe ) nanocrystals with a mean size of 5.35 nm have been synthesized by an electrochemical technique. Structural analysis by transmission electron microscopy and glancing angle X-ray diffraction studies indicate the presence of cubic phase HgTe nanocrystals in the deposit. Optical absorption measurements reveal two well resolved excitonic peaks around 578.5 nm and 550 nm attributed to heavy hole valence band (HVB)–conduction band (CB) and light hole valence band (LVB)–CB transitions, respectively, and suggest a band opening of bulk inverted narrow band gap HgTe as a result of strong quantum confinement effect (QCE). Visible photoluminescence (PL) of HgTe nanocrystals indicates free exciton transition around 579.5 nm as observed from the PL measurement at 300 K along with a bound exciton dominated band around 588 nm. Micro-Raman measurements at 300 K indicate the 1LO vibrational mode at 142.6 cm-1 shifted by 6 cm-1 from its standard bulk value and confirm the QCE.

scholarly journals New Electrospun ZnO:MoO3 Nanostructures: Preparation, Characterization and Photocatalytic Performance

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1476 ◽  
Author(s):  
Petronela Pascariu ◽  
Mihaela Homocianu ◽  
Niculae Olaru ◽  
Anton Airinei ◽  
Octavian Ionescu
Keyword(s):  
Photocatalytic Performance ◽  
Molybdenum Trioxide ◽  
Blue Shift ◽  
Band Gap Energy ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Electron Microscopies ◽  
Reaction Rate Constants ◽  
Transmission Electron ◽  
Electrospinning Method

New molybdenum trioxide-incorporated ZnO materials were prepared through the electrospinning method and then calcination at 500 °C, for 2 h. The obtained electrospun ZnO:MoO3 hybrid materials were characterized by X-ray diffraction, scanning and transmission electron microscopies, ultraviolet (UV)-diffuse reflectance, UV–visible (UV–vis) absorption, and photoluminescence techniques. It was observed that the presence of MoO3 as loading material in pure ZnO matrix induces a small blue shift in the absorption band maxima (from 382 to 371 nm) and the emission peaks are shifted to shorter wavelengths, as compared to pure ZnO. Also, a slight decrease in the optical band gap energy of ZnO:MoO3 was registered after MoO3 incorporation. The photocatalytic performance of pure ZnO and ZnO:MoO3 was assessed in the degradation of rhodamine B (RhB) dye with an initial concentration of 5 mg/L, under visible light irradiation. A doubling of the degradation efficiency of the ZnO:MoO3 sample (3.26% of the atomic molar ratio of Mo/Zn) as compared to pure ZnO was obtained. The values of the reaction rate constants were found to be 0.0480 h−1 for ZnO, and 0.1072 h−1 for ZnO:MoO3, respectively.

scholarly journals Quantum Confinement Effect and Photoenhancement of Photoluminescence of PbS and PbS/MnS Quantum Dots

2020 ◽  
Vol 10 (18) ◽  
pp. 6282
Author(s):  
Muhammad Safwan Zaini ◽  
Josephine Ying Chyi Liew ◽  
Shahrul Ainliah Alang Ahmad ◽  
Abdul Rahman Mohmad ◽  
Mazliana Ahmad Kamarudin
Keyword(s):  
Aqueous Solution ◽  
Quantum Dots ◽  
Quantum Confinement ◽  
Shell Thickness ◽  
Quantum Confinement Effect ◽  
Band Gap Energy ◽  
Confinement Effect ◽  
Core Shell ◽  
Lead Sulphide ◽  
Peak Energy

The quantum confinement effect and photoenhancement of photoluminescence (PL) of lead sulphide (PbS) quantum dots (QDs) and lead sulphide/manganese sulphide (PbS/MnS) core shell QDs capped with thiol ligands in aqueous solution were investigated. From PL results, the presence of MnS shells gives a strong confinement effect which translates to higher emission energy in PbS/MnS core shell QDs. Increasing MnS shell thickness from 0.3 to 1.5 monolayers (ML) causes a blueshift of PL peak energies as the charge carriers concentrated in the PbS core region. Enhancement of the PL intensity of colloidal PbS and PbS/MnS core shell QDs has been observed when the samples are illuminated above the band gap energy, under continuous irradiation for 40 min. Luminescence from PbS QDs and PbS/MnS core shell QDs can be strongly influenced by the interaction of water molecules and oxygen present in aqueous solution adsorbed on the QD surface. However, PbS/MnS core shell QDs with a shell thickness of 1.5 ML did not show a PL peak energy stability as it was redshifted after 25 min, probably due to wider size distribution of the QDs.

Synthesis of Zn Doped CdSe Quantum Dots via Inverse Micelle Technique

2014 ◽  
Vol 807 ◽  
pp. 115-121 ◽  
Author(s):  
Fatihah Aplop ◽  
Mohd Rafie bin Johan
Keyword(s):  
Quantum Dots ◽  
Quantum Confinement Effect ◽  
Blue Shift ◽  
X Ray Diffraction ◽  
Cdse Qds ◽  
Xrd Pattern ◽  
Transmission Electron ◽  
Inverse Micelle ◽  
Cadmium Selenide Quantum Dots ◽  
The Fourier Transform

Zinc doped Cadmium Selenide Quantum Dots (CdSe/Zn QDs) were synthesized via inverse micelle technique. The absorption spectra exhibit a strong blue-shift characteristic due to quantum confinement effect. The X-ray Diffraction (XRD) pattern showed the zinc-blende phase of Zn doped CdSe QDs. Transmission Electron Microscopy (TEM) images suggested that the sizes of QDs were falls in range between 2 – 8 nm, with narrow size distribution. The TEM images also revealed that the Zn doped CdSe QDs were spherical, having a compact and dense structure. The optical bandgap of Zn-doped CdSe QDs are smaller than the undoped CdSe QDs as shown in Tauc’s plot. The fourier transform infrared spectra proves the complexion of CdSe-Zn QDs.

Correlation Between Microstructure and Optical Properties of ZnO Based Nanostructures Grown by MOCVD

2008 ◽  
Vol 1074 ◽  
Author(s):  
Farid Falyouni ◽  
Julien Barjon ◽  
Vincent Sallet ◽  
Alain Lusson ◽  
Guy Garry ◽  
...  
Keyword(s):  
Low Temperature ◽  
Structural Properties ◽  
Quantum Confinement ◽  
Dopant Concentration ◽  
Quantum Confinement Effect ◽  
Chemical Vapor ◽  
Blue Shift ◽  
Transmission Electron ◽  
Optical Signature ◽  
Excitonic Emission

ABSTRACTThe correlation between structural properties of ZnO sharp conical needles grown by Metallorganic Chemical Vapor Deposition (MOCVD) on sapphire substrate and their optical signature measured by low temperature cathodoluminescence (CL) is investigated. Transmission Electron Microscopy (TEM) shows the excellent structural properties of these needles from their base up to the end of the tip. In order to probe the emission of the needles along their length, UV CL mapping has been performed at low temperature on a single needle previously characterized by TEM. A clear blue shift of 25meV is observed for the excitonic emission close to the needle tip. This shift is too high to be fully attributed to quantum confinement. Although, it qualitatively agrees with previous observations which assigned it to a surface contribution becoming dominant upon size shrinking, the effect is less pronounced. The results are discussed in term of surface quality and other possible contributions associated to a decrease of the n-dopant concentration and to quantum confinement effect close to the tip.

Growth and Optical Properties of SnO2 Ultra-Small Nanorods by the Novel Micelle Techniques

2008 ◽  
Vol 1087 ◽  
Author(s):  
Satchidananda Rath ◽  
Shinji Nozaki ◽  
Hiroshi Ono ◽  
Kazuo Uchida ◽  
Satoshi Khojima
Keyword(s):  
Quantum Confinement ◽  
Photoluminescence Spectrum ◽  
Tin Dioxide ◽  
Optical Band Gap ◽  
Quantum Confinement Effect ◽  
Average Diameter ◽  
The Novel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

AbstractTin-dioxide (SnO2) ultra-small nanorods (UNR) have been successfully synthesized using the novel micellar technique. From transmission electron microscopy, the average diameter and length of the UNRs are estimated to be 1.3 nm and 5.0 nm, respectively. The crystal structure of the SnO2 UNRs was found to be tetragonal from the glazing incidence x-ray diffraction. The optical band gap estimated from the absorption spectrum is blue-shifted by 1 eV from that of bulk (3.64 eV). The photoluminescence spectrum shows two groups of peaks each with several fine peaks, one in the wavelength range of 270 – 370 nm and the other in the range of 380 – 500 nm which are due to the strong quantum confinement effect.

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