This paper reports on the preparation of high purity ZnS nanoparticles by a facile single step solvent-free route via thermal decomposition of zinc acetate dihydrate and thiourea in air atmosphere. The third-order optical nonlinearity of the prepared ZnS nanoparticles were measured by Z-scan technique using continuous wave 532-nm diode pumped Nd:YAG laser. From nonlinear optical (NLO) measurements, the prepared ZnS nanoparticles possess negative nonlinearity i.e., self-defocusing. Open aperture Z-scan measurement shows saturable absorption within the medium. These results show that the prepared ZnS nanoparticles are promising candidate for various potential applications in the field of nonlinear optics.

Vinitha G

Physics

School of Advanced Sciences

Chennai Campus

Mohan R

Mechanical

School of Mechanical Engineering

Vijai Anand K

Karl Chinnu M

Jayavel R.

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Enhanced third-order nonlinear optical properties of high purity ZnS nanoparticles

Journal of Nonlinear Optical Physics & Materials

Synthesis of hydrazine hydrate assisted manganese doped zinc selenides by hydrothermal technique led to the formation of good quality nanospheres which are controlled by Ostwald ripening process. Structural studies using XRD showed the incorporation of manganese in zinc selenide matrix with their crystallite sizes ranging between 10 and 15 nm, which corroborate with the TEM measurements. Dominant emission (517 nm) corresponds to the near band edge emission as observed from photoluminescence spectra. Presence of impurities and defects were identified from various other emissions as well as from the bandgap variation obtained from reflectance spectra. The third order nonlinearity of manganese doped zinc selenide nanoparticles were calculated by the standard Z-scan technique using 532 nm CW DPSS and nanopulsed Nd:YAG laser. Mn doped ZnSe nanoparticles which exhibits near resonant excited state absorption were found to be an ideal candidate to be exploited as optical limiters in protecting optical components from high intense laser pulses. Further, lower onset optical limiting threshold under pulsed laser excitation of manganese doped zinc selenides (2.92 × 1012 Wm−2) compared to pure zinc selenide (4.98 × 1012 Wm−2) confirms that doping of Mn in ZnSe can yield efficient energy absorbing optical limiters. © 2020 Elsevier B.V.

Optical Materials

Investigations on the structural, morphological, linear and third order nonlinear optical properties of manganese doped zinc selenide nanoparticles for optical limiting application

Phase purity plays an important role in determining the properties of the material and its subsequent applications which depends on the synthesis conditions and dopant concentrations. Phase pure zinc selenide and nickel doped zinc selenide nanoparticles were synthesized by hydrothermal method using sodium selenite as precursor. Calculated crystallite size for various compositions showed a decrease with dopant concentration with the values around 10 nm and less. Morphological analysis showed the formation of spherical particles which is distinct in the micron scale image. SAED pattern showed the formation of nanocrystalline particles with particles size varying between 10 and 20 nm. Quantum confinement effect due to reduced size was corroborated with increased band gap values as measured from diffuse reflectance spectra. Photoluminescence spectra showed the presence of dominant near band-edge emission along with certain defect level emissions for all the samples. Nonlinear optical studies carried out using a continuous wave laser showed an increase in nonlinear refractive index and susceptibility values with dopant concentration signifying the role of defects and the structural modifications occurring due to doping. The nonlinear optical properties exhibited by this material has been utilized for device applications like optical limiting and the results show enhancement in limiting efficiency with dopant concentrations. © 2019 Elsevier B.V.

Journal of Alloys and Compounds

Synthesis and characterization of nickel doped zinc selenide nanospheres for nonlinear optical applications

This study reports the third-order nonlinear optical (NLO) properties of hexamethylenetetramine (HMTA) stabilized pure and transition metals (Cu, Co and Mn) doped ZnS nanoparticles (NPs) and their electronic structures. The third-order NLO properties of pure and transition metals (Cu, Co and Mn) doped ZnS NPs were measured by [Formula: see text]-scan technique. From these measurements, the pure and doped ZnS samples exhibit negative nonlinearity i.e., self-defocusing. The open aperture [Formula: see text]-scan measurement shows saturated absorption within the medium. The prepared pure and doped ZnS samples exhibit nonlinear refractive index of the order of 10[Formula: see text][Formula: see text](cm2/W), nonlinear absorption (NLA) coefficient of the order of 10[Formula: see text][Formula: see text]cm/W and nonlinear optical susceptibility of the order of 10[Formula: see text][Formula: see text]esu. The electronic structures of these ZnS NPs were investigated using near edge X-ray absorption fine structure (NEXAFS) measurements at the C K-, N K- and Co L[Formula: see text]-edges. The C K- and N K-edges XANES spectra reveal the appearance of several spectral features in the range 285–290[Formula: see text]eV and 390–430[Formula: see text]eV respectively. The Co L[Formula: see text]-edge NEXAFS spectrum exhibits multiplet absorption lines similar to those of Co[Formula: see text] ions coordinated in tetrahedral symmetry with four sulfur nearest neighbors. These results clearly demonstrate that divalent Co ions substitute Zn sites. From the Raman spectra, the appearance of multiple resonance Raman peaks indicates that the prepared ZnS samples have good optical quality.

Enhancement of third-order nonlinear optical properties of HMTA stabilized pure and doped ZnS nanoparticles and their electronic structures

Quantum dots of zinc gallate (ZnGa2O4) has been synthesized by wet chemical route at a temperature of 90 °C. The structural, linear and nonlinear optical properties of ZnGa2O4 were investigated. Electronic band structure calculations are carried out for ZnGa2O4, using density functional approach and the electron effective mass, hole effective mass and band gap are evaluated as 0.27me, 16.10me and 4.58eV respectively, from which the exciton Bohr radius is estimated to be 2.72 nm. From transmission electron microscopy, size of cubic spinel ZnGa2O4 quantum dots is obtained as 8.3 nm. The theoretical band gap for ZnGa2O4 estimated using Brus equation is 4.6eV and it agrees with band gap assessed from diffuse reflectance measurements. The sample shows blue emission under UV excitation. Nonlinear optical characterization of ZnGa2O4 is done using open and closed aperture z scan technique and it shows saturable absorption and self-defocusing behavior making it suitable for display and nonlinear photonic devices. © 2018 Elsevier B.V.

Low temperature synthesis and characterization of zinc gallate quantum dots for optoelectronic applications

Author index Volume 24

Journal of Experimental Nanoscience

Low-temperature synthesis of hexamethylenetetramine-stabilised ZnS nanoparticles and its photocatalytic properties

International Journal of Nanoscience

CONTROLLED SYNTHESIS AND CHARACTERIZATION OF CERIUM-DOPED ZnS NANOPARTICLES IN HMTA MATRIX

Physica B: Condensed Matter

Synthesis and photoluminescent and nonlinear optical properties of manganese doped ZnS nanoparticles

Thermal stability and optical properties of HMTA capped zinc sulfide nanoparticles

Journal	Journal of Nonlinear Optical Physics & Materials
Publisher	World Scientific Pub Co Pte Lt
ISSN	0218-8635
Open Access	0