scholarly journals Structural and Optoelectronic Properties of Zinc Sulfide Thin Films Synthesized by Co-Precipitation Method

2019 ◽  
Vol 27 (2) ◽  
pp. 287-302
Author(s):  
V.H. Choudapur ◽  
S.B. Kapatkar ◽  
A.B. Raju
Keyword(s):  
Zinc Sulfide ◽  
Energy Gap ◽  
Quantum Confinement Effect ◽  
Wide Bandgap ◽  
Precipitation Method ◽  
Cubic Phase ◽  
Uv Detectors ◽  
Sulphur Concentration ◽  
Co Precipitation ◽  
Sulfide Nanocrystals

Abstract Wide bandgap Zinc Sulfide nanocrystals are prepared by a simple co-precipitation method at different precursor concentrations. The influence of sulphur concentration in Zinc sulfide on morphological, optical and electric properties is found to be significant. The Zinc Sulfide nanomaterial was prepared using low-cost starting materials and deionised water as the solvent. As synthesized Zinc Sulfide nanocrystals were analyzed using X-ray diffraction (XRD), Energy Dispersive Spectroscopy (EDS) analysis, UV-Visible Spectrophotometry, Photoluminescence (PL), Scanning electron Microscopy (SEM), Ellipsometry techniques and electric conductivity measurements. XRD patterns revealed that ZnS nanocrystals are polycrystalline, cubic phase with (111) preferred orientation. The obtained crystallites have sizes in the range of 5 to 11 nm. EDS pattern confirms the purity of the films. From optical absorption measurements, it is clear that the direct energy gap decreases from 5.2 to 4.4eV with the increase in sulphur concentration in ZnS and exhibit large quantum confinement effect. Ellipsometry was used to determine the optical constants and film thickness. The films deposited on ITO – coated glass was used to record the IV Characteristics of the films by two probe method. The wide-bandgap, conducting materials have applications in optoelectronic devices such as high-frequency UV detectors and thin-film solar cells.

scholarly journals Synthesis and characterization of N, O-donor Schiff base capped ZnS NPs as a sensor for fluorescence selective detection of Fe 3+, Cr 2+ and Cd 2+ ions

2018 ◽  
Vol 4 (4) ◽  
pp. 151-162
Author(s):  
Dasari Ayodhya ◽  
Guttena Veerabhadram
Keyword(s):  
Schiff Base ◽  
Quantum Confinement ◽  
Metal Ion ◽  
Quantum Confinement Effect ◽  
Precipitation Method ◽  
Donor Ligand ◽  
Zinc Sulfide Nanoparticles ◽  
Co Precipitation ◽  
Selective Sensor

We report the simple synthesis of zinc sulfide nanoparticles (ZnSNPs) by a co-precipitation method using Schiff base, (2-[(4-methoxy-phenylimino)-methyl]-4-nitro phenol) as a capping agent. Here, Schiff base is also used as N, O-donor ligand to control the morphology of NPs and fluorescence interactions. The formation of ZnSNPs and their optical, structural, thermal properties and morphologies were studied by means of UV–vis DRS, fluorescence, FTIR, XRD, SEM, TEM, zeta potential and TGA. The optical properties and quantum confinement effect of the products were confirmed by means of spectroscopic measurements. XRD and TEM image shows that the synthesized ZnSNPs have cubic structures with a diameter of about less than 10 nm. The prepared ZnSNPs exhibited as a selective probe detection of Fe3+, Cr2+ and Cd2+ ions by fluorometrically and the emission band which disappears in the presence of increasing concentrations of Fe3+, Cr2+ and Cd2+ ions. Based on the fluorescence quenching of the NPs in the presence of metal ion of interest, the feasibility of their determinations was examined according to the Stern-Volmer equation. Our work suggested that Schiff base capped ZnSNPs could be a potential selective sensor in the detection of heavy metal ions.

scholarly journals Crystallographic, Energy Gap, Photoluminescence and Photo-Catalytic Investigation of Cu Doped Cd0.9Zn0.1S Nanostructures by Co-Precipitation Method

2021 ◽  
Author(s):  
P. Raju ◽  
Joseph Prince Jesuraj ◽  
S. Muthukumaran
Keyword(s):  
Crystallite Size ◽  
Energy Gap ◽  
Wavelength Region ◽  
Lattice Parameter ◽  
Precipitation Method ◽  
Optical Absorbance ◽  
Stability Measurement ◽  
Cubic Structure ◽  
The Stability ◽  
Co Precipitation

Abstract The controlled synthesis of Cd0.9Zn0.1S, Cd0.89Zn0.1Cu0.01S and Cd0.87Zn0.1Cu0.03S nanostructures by simple chemical co-precipitation technique was reported. The XRD investigation confirmed the basic CdS cubic structure on Zn-doped CdS and also Zn, Cu dual doped CdS with no secondary/impurity related phases. No modification in cubic structure was detected during the addition of Zn/Cu into CdS. The reduction of crystallite size from 63 Å to 40 Å and the changes in lattice parameter confirmed the incorporation of Cu into Cd0.9Zn0.1S and generation of Cu related defects. The shift of absorption edge along upper wavelength region and elevated absorption intensity by Cu doping can be accredited to the collective consequence of quantization and the generation of defect associated states. The enhanced optical absorbance and the reduced energy gap recommended that Cd0.87Zn0.1Cu0.03S nanostructure is useful to enhance the efficiency of opto-electronic devices. The presence of Cd-S / Zn-Cd-S /Zn/Cu-Cd-S chemical bonding were confirmed by Fourier transform infrared investigation. The elevated green emissions by Cu incorporation was explained by decrease of crystallite size and creation of more defects. Zn, Cu dual doped CdS nanostructures are recognized as the possible and also efficient photo-catalyst for the removal dyes like methylene blue. The enhanced photo-catalytic behaviour of Zn, Cu dual doped CdS is the collective consequences of high density electron-hole pairs creation, enhanced absorbance in the visible wavelength, surface area enhancement, reduced energy gap and the formation of novel defect associated states. The stability measurement signified that Cu doped Cd0.9Zn0.1S exhibits superior dye removal ability and better stability even after 6 repetitive runs with limited photo-corrosion.

scholarly journals Augmented band gap tunability in indium-doped zinc sulfide nanocrystals

Nanoscale ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 3154-3163 ◽  
Author(s):  
Enrico Della Gaspera ◽  
Joseph Griggs ◽  
Taimur Ahmed ◽  
Sumeet Walia ◽  
Edwin L. H. Mayes ◽  
...  
Keyword(s):  
Band Gap ◽  
Zinc Sulfide ◽  
Quantum Confinement ◽  
Quantum Confinement Effect ◽  
Confinement Effect ◽  
Indium Doping ◽  
Zns Nanocrystals ◽  
Sulfide Nanocrystals

Indium doping in ZnS nanocrystals heavily affects the band gap beyond quantum confinement effect with unprecedented tunability in the UVA/UVB range.

Synthesis of Zn1−xCdxO Nanoparticles by Co-Precipitation: Structural, Optical and Photodetection Analysis

2017 ◽  
Vol 17 (01n02) ◽  
pp. 1760015 ◽  
Author(s):  
Anju Anna Jacob ◽  
L. Balakrishnan ◽  
S. R. Meher ◽  
K. Shambavi ◽  
Z. C. Alex
Keyword(s):  
Zinc Oxide ◽  
Energy Dispersive Spectrometer ◽  
Ultra Violet ◽  
Wide Bandgap ◽  
Precipitation Method ◽  
Cutoff Wavelength ◽  
X Ray ◽  
Wide Bandgap Semiconductor ◽  
Co Precipitation ◽  
Scanning Electron

Zinc oxide (ZnO) is a wide bandgap semiconductor with excellent photoresponse in ultra-violet (UV) regime. Tuning the bandgap of ZnO by alloying with cadmium can shift its absorption cutoff wavelength from UV to visible (Vis) region. Our work aims at synthesis of Zn[Formula: see text]CdxO nanoparticles by co-precipitation method for the fabrication of photodetector. The properties of nanoparticles were analyzed using X-ray diffractometer, UV–Vis spectrometer, scanning electron microscope and energy dispersive spectrometer. The incorporation of cadmium without altering the wurtzite structure resulted in the red shift in the absorption edge of ZnO. Further, the photoresponse characteristics of Zn[Formula: see text]CdxO nanopowders were investigated by fabricating photodetectors. It has been found that with Cd alloying the photosensitivity was increased in the UVA-violet as well in the blue region.

Synthesis and Optical Properties of Annealed Cr Doped ZnS Nanoparticles

2013 ◽  
Vol 678 ◽  
pp. 163-167 ◽  
Author(s):  
D. Amaranatha Reddy ◽  
G. Murali ◽  
N. Madhusudhana Rao ◽  
R.P. Vijayalakshmi ◽  
B.K. Reddy
Keyword(s):  
Optical Properties ◽  
Hexagonal Phase ◽  
Blue Emission ◽  
Precipitation Method ◽  
Cubic Phase ◽  
Structural And Optical Properties ◽  
Zns Nanoparticles ◽  
Blue Emission Peak ◽  
Co Precipitation ◽  
Surface Morphologies

Undoped and Cr doped ZnS nanoparticles with Cr concentrations of 3.0 at.% were prepared by a chemical co-precipitation method for the fist time, using 2-Mercaptoethanol as the capping agent and annealed the synthesized particles at 600°C for 3h in air. The effect of annealing on morphological, structural and optical properties of ZnS and ZnS:Cr have been studied and compared with as prepared samples. EDAX measurements confirmed the presence of Cr in the ZnS lattice and it also confirms the conversion of ZnS into ZnO after annealed at 600 0C/3h. Surface morphologies of all samples were characterized using scanning electron microscopy (SEM). XRD spectra of as synthesized nanoparticles of ZnS and ZnS:Cr exhibited cubic phase. After annealing, the cubic phase is transformed into hexagonal phase. The particle sizes of the ZnS:Cr powders were increased from 5 to 30 nm when the powders were annealed at 600°C. A stable blue emission peak at 445 nm is observed from the as prepared samples (pure ZnS and Cr doped ZnS) but annealed at 600 0C the PL peaked at 500 nm for pure ZnS and Cr doped ZnS nanoparticles exhibited PL peak at 500 nm as well as 654 nm. The emission intensity decreased in annealed particles compared to as synthesized samples.

scholarly journals Thermopower Enhancement of Rutile-type SnO2 Nanocrystalline Using Facile Co-Precipitation Method

2020 ◽  
Vol 20 (2) ◽  
pp. 82
Author(s):  
Nadya Larasati Kartika ◽  
Budi Adiperdana ◽  
Asep Ridwan Nugraha ◽  
Ardita Septiani ◽  
Dadang Mulyadi ◽  
...  
Keyword(s):  
Seebeck Coefficient ◽  
Density Functional ◽  
Energy Gap ◽  
Oxide Semiconductor ◽  
Precipitation Method ◽  
Strongly Correlated ◽  
X Ray Diffraction ◽  
High Carrier Mobility ◽  
Co Precipitation ◽  
Quantum Espresso

Metal oxide semiconductor has attracted so much attention due to its high carrier mobility. Herein, thermoelectric study of nanocrystalline SnO2 through a simple co-precipitation method is conducted to enhance the Seebeck coefficient (S). X-ray diffraction, thermogravimetric analysis (TGA), resistivity (r), Seebeck coefficient (S), and power factor (PF) measurements are conducted to analyze the thermoelectric properties of the material. The measurements show that there are two interesting results, which are the unusual resistivity behavior and the high value of the S. Resistivity behavior shows a non-reflective intermediate semiconductor-metals behavior where the turning point occurs at 250 o C. This behavior is strongly correlated to the surface oxide reaction due to annealing temperature. The maximum S likely occurs at 250 ºC, since the curve shows a slight thermopower peak at 250 ºC. The value of the S is quite high with around twenty times higher than other publications about SnO2 thermoelectric material, this happens due to the bandgap broadening. The energy gap of SnO2 calculated using density functional theory (DFT), which was performed by Quantum Espresso 6.6. The result shows that there is a broadening energy gap at different momentum or wave factor. Nanocrystalline semiconductors material is giving an impact to increase the width of bandgap due to quantum confinement and could enhance the thermopower especially in SnO2 nanocrystalline

Prominent Visible Light Photocatalytic and Water Purification Activity of PbS/CdS/CdO Nanocomposite Synthesized via Simple Co-Precipitation Method

2019 ◽  
Vol 9 (2) ◽  
pp. 278-284
Author(s):  
Mohammad Sabet ◽  
Marziyeh Mohammadi ◽  
Fatemeh Googhari
Keyword(s):  
Cadmium Sulfide ◽  
Water Solution ◽  
Hexagonal Phase ◽  
Wide Band ◽  
Precipitation Method ◽  
Cubic Phase ◽  
Distilled Water ◽  
Hydrothermal Route ◽  
Sem Images ◽  
Co Precipitation

Background: Due to unique chemical and physical properties and potential application in many fields, nanostructured materials have attracted many attentions. Cadmium sulfide (CdS) is a semiconductor that has a wide band gap of 2.42 eV at room temperature and can be served in solar cells and photoluminescence devices. Cadmium sulfide (CdS) is a kind of attractive semiconductor material, and it is now widely used for optoelectronic applications. CdS nano and microstructures can be synthesized via different chemical methods such as microwave-solvothermal synthesis, surfactant-ligand coassisting solvothermal method and hydrothermal route. Also different morphologies of this semiconductor such as dendrites, nanorods, sphere-like, flakes, nanowires, flower-like shape triangular and hexagonal plates, were synthesized. Methods: To synthesis of the nanocomposite, a simple co-precipitation method was served. In briefly, 0.1 g of Pb(NO3)2 was dissolved in the distilled water (Solution 1). Also different aqueous solutions were made from dissolving different mole ratio of Cd(NO3)2.6H2O respect to the lead source in the water (Solution 2). Two solutions were mixed together under vigorous stirring and then S2- solution (0.02 g thiourea in the water) was added to the Pb2+/Cd2+ solution. After that 0.1 g of CTAB as surfactant was added to the final solution. Finally to the synthesis of both sulfide and oxide nanostructures, NaOH solution was added to the prepared solution to obtain pH= 10. Distilled water and absolute ethanol were used to wash the obtained precipitate and then it dried at 80 °C for 8 h. Results: From the XRD pattern it was found that the peaks placed at 24.9°, 27°, 44.1°, 48°, 52°, 54°, 57.8°, 66.8°, 71.2° are associated to CdS compound with hexagonal phase (JCPDS=00-001-0780) that belong to (100), (002), (110), (103), (112), (201), (202), (203), (211) Miller indices respectively. The Other peaks belong to PbS with hexagonal phase (JCPDS=01-078-1897), and CdO with cubic phase (JCPDS=00-001-1049). From SEM images, it was found by choosing the mole ratio to 1:1, very small and uniform particles were achieved. By increasing Pb2+/Cd2+ mole ratio to 1:2, very tiny particles aggregated together were achieved. Conclusion: The results showed that the product can adsorb extra 80% of heavy metal ions from the water. So it can be said that the nanocomposite can be used in the water treatment due to its high photocatalytic and surface adsorption activities. In other words, it can remove heavy metals from the water and also decompose organic pollutions.

SYNTHESIS AND CHARACTERIZATION OF (CdSe)1-X(ZnS)x MIXED POLYCRYSTALLINE SEMICONDUCTORS BY CO-PRECIPITATION METHOD

2002 ◽  
Vol 16 (19) ◽  
pp. 2885-2899
Author(s):  
K. YADAIAH ◽  
ABDUL NAYEEM ◽  
M. SOMI REDDY ◽  
M. NAGABHOOSHANAM
Keyword(s):  
Energy Gap ◽  
Nitrogen Atmosphere ◽  
Hexagonal Structure ◽  
Ion Source ◽  
Precipitation Method ◽  
Scanning Electron Micrographs ◽  
Chemical Homogeneity ◽  
X Ray ◽  
Co Precipitation

The polycrystalline (CdSe)1-x (ZnS)x semiconductor powder with (0 ≤ x ≤ 1) has been prepared by controlled co-precipitation method from an alkaline medium using thiourea as a sulphide ion source. Pellets are made out of these powders under 10 tonnes/sq.cm pressure and are sintered at 800°C for 2 hours in nitrogen atmosphere. X-ray studies have indicated that the compounds are polycrystalline in nature with mixed hexagonal structure of CdSe with x = 0-0.3 and cubic structure of ZnS with x = 1. The chemical homogeneity of the samples was observed from the EDAX and also noted that the atomic contents present were as per the constituents taken in the solution. Lattice parameters (a and c) of all the compounds are determined from the X-ray data and are found to decrease with the increase in ZnS content. It is also observed that the grain size decreases with the increase in x from 0-0.6 and later it remained almost the same till x reaches 0.9. Optical studies indicated that the energy gap was as high as 5.2 eV and remained almost same throughout the composition range x = 0-1. Scanning electron micrographs have shown platelet like structure in CdSe and mixed compounds where as a mixed Cubic and Hexagonal structure in ZnS. The results are explained based on different phases present in the compounds.

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.

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