Monodispersed ZnS nanoparticles (NPs) were prepared by the chemical precipitation method. Thermally induced structural, morphological and optical changes have been investigated using x-ray diffraction, high-resolution transmission electron microscopy, optical absorption, photoluminescence (PL), and Fourier transform infrared and Raman spectroscopy. It was found that D increases with increasing annealing temperature (T a). The onset of the ZnS phase transition from cubic to hexagonal structure takes place at 400 °C, while cubic ZnS transforms into hexagonal ZnO via thermal oxidation in air at 600 °C. It is also noted that increasing T a results in the red shift of the optical band gap (Eg ) and the thermal bleaching of exciton absorption. The PL spectrum of as-prepared ZnS nanopowder shows UV emission bands at 363 and 395 nm and blue and green emission at 438 and 515 nm, respectively. With increasing T a up to 500 °C, these bands were quenched and red-shifted. In addition, the UV irradiation effects on colloidal ZnS NPs were investigated. UV irradiation at a dose  <13 J cm−2 leads to a decrease in D, the blue shift of Eg and the enhancement of PL intensity. This behavior was explained in terms of surface modification by photopolymerization, the formation of a ZnSO4 passivation laye, as well as the reduction of D by photo-corrosion. At a UV irradiation dose  <13 J cm−2 both Eg and D did not change and PL intensity was quenched, which were caused by the creation of nonradiative surface states by the photodegradation of the capping agent and photo passivated layer. The mechanism of the PL emission process in ZnS NPs was discussed and an energy band diagram was proposed.

Polycrystalline cubic CdS nanoparticles (NPs) with a crystallite size (DSch) ~3 nm were synthesized by chemical precipitation method at room temperature. Thermal induced structural and morphological changes have been investigated using x-ray diffraction, high-resolution transmission electron microscope, x-ray fluorescence, Fourier transform infrared and Raman spectroscopy. The influence of these changes on optical absorption and photoluminescence (PL) characteristics have been studied. It was found that increasing annealing temperature (Ta), results in structural phase transitions at 300 and 700 °C, increasing DSch and red shift of the optical band gap (Eg) due to the improvement in crystallinity. The photoluminescence emission spectrum of nonstoichiometric CdS (Cd-rich) nanopowder reveals emission bands at 365, 397, and 434 nm. Furthermore, PL spectrum of colloidal solution exhibits additional green and red emission bands at 535, 570 and 622 nm. To explain the mechanism of PL emission in CdS NPs, trapping and radiative recombination levels have been identified and the corresponding energy band diagrams are suggested. Annealing process results in an overall enhancement in PL intensity due to the improvement in crystallinity associated with the reduction of nonradiative surface state defects. Irradiation of CdS NPs colloidal solution at UV irradiation dose <13 J cm−2 leads to the enhancement of PL quantum efficiency and blue shift of Eg(i.e. photo-brightening) due to the decrease in the particle size deduced from Brus equation (D), This behavior is due to UV irradiation effects suchas photopolymerization, the formation of CdSO4 passivation layers due to photooxidation and the reduction in DBrus by photocorrosion process. At UV irradiation dose <13 J cm−2,PL emission intensity continuously enhances without any change in both Eg and D. This
behavior is discussed in terms of electron filling model. Boltzmann curve fitting successfully describes the dependence of both DBrus and Eg on UV irradiation dose.

Polycrystalline cubic CdS nanoparticles (NPs) with a crystallite size (DSch) ~3 nm were synthesized by chemical precipitation method at room temperature. Thermal induced structural and morphological changes have been investigated using x-ray diffraction, high-resolution transmission electron microscope, x-ray fluorescence, Fourier transform infrared and Raman spectroscopy. The influence of these changes on optical absorption and photoluminescence (PL) characteristics have been studied. It was found that increasing annealing temperature (Ta), results in structural phase transitions at 300 and 700 °C, increasing DSch and red shift of the optical band gap (Eg) due to the improvement in crystallinity. The photoluminescence emission spectrum of nonstoichiometric CdS (Cd-rich) nanopowder reveals emission bands at 365, 397, and 434 nm. Furthermore, PL spectrum of colloidal solution exhibits additional green and red emission bands at 535, 570 and 622 nm. To explain the mechanism of PL emission in CdS NPs, trapping and radiative recombination levels have been identified and the corresponding energy band diagrams are suggested. Annealing process results in an overall enhancement in PL intensity due to the improvement in crystallinity associated with the reduction of nonradiative surface state defects. Irradiation of CdS NPs colloidal solution at UV irradiation dose <13 J cm−2 leads to the enhancement of PL quantum efficiency and blue shift of Eg(i.e. photo-brightening) due to the decrease in the particle size deduced from Brus equation (D), This behavior is due to UV irradiation effects suchas photopolymerization, the formation of CdSO4 passivation layers due to photooxidation and the reduction in DBrus by photocorrosion process. At UV irradiation dose <13 J cm−2,PL emission intensity continuously enhances without any change in both Eg and D. This
behavior is discussed in terms of electron filling model. Boltzmann curve fitting successfully describes the dependence of both DBrus and Eg on UV irradiation dose.

Polycrystalline cubic CdS nanoparticles (NPs) with a crystallite size (DSch) ~3 nm were synthesized by chemical precipitation method at room temperature. Thermal induced structural and morphological changes have been investigated using x-ray diffraction, high-resolution transmission electron microscope, x-ray fluorescence, Fourier transform infrared and Raman spectroscopy. The influence of these changes on optical absorption and photoluminescence (PL) characteristics have been studied. It was found that increasing annealing temperature (Ta), results in structural phase transitions at 300 and 700 °C, increasing DSch and red shift of the optical band gap (Eg) due to the improvement in crystallinity. The photoluminescence emission spectrum of nonstoichiometric CdS (Cd-rich) nanopowder reveals emission bands at 365, 397, and 434 nm. Furthermore, PL spectrum of colloidal solution exhibits additional green and red emission bands at 535, 570 and 622 nm. To explain the mechanism of PL emission in CdS NPs, trapping and radiative recombination levels have been identified and the corresponding energy band diagrams are suggested. Annealing process results in an overall enhancement in PL intensity due to the improvement in crystallinity associated with the reduction of nonradiative surface state defects. Irradiation of CdS NPs colloidal solution at UV irradiation dose <13 J cm−2 leads to the enhancement of PL quantum efficiency and blue shift of Eg(i.e. photo-brightening) due to the decrease in the particle size deduced from Brus equation (D), This behavior is due to UV irradiation effects suchas photopolymerization, the formation of CdSO4 passivation layers due to photooxidation and the reduction in DBrus by photocorrosion process. At UV irradiation dose <13 J cm−2,PL emission intensity continuously enhances without any change in both Eg and D. This
behavior is discussed in terms of electron filling model. Boltzmann curve fitting successfully describes the dependence of both DBrus and Eg on UV irradiation dose.

Polycrystalline cubic CdS nanoparticles (NPs) with a crystallite size (DSch) ~3 nm were synthesized by chemical precipitation method at room temperature. Thermal induced structural and morphological changes have been investigated using x-ray diffraction, high-resolution transmission electron microscope, x-ray fluorescence, Fourier transform infrared and Raman spectroscopy. The influence of these changes on optical absorption and photoluminescence (PL) characteristics have been studied. It was found that increasing annealing temperature (Ta), results in structural phase transitions at 300 and 700 °C, increasing DSch and red shift of the optical band gap (Eg) due to the improvement in crystallinity. The photoluminescence emission spectrum of nonstoichiometric CdS (Cd-rich) nanopowder reveals emission bands at 365, 397, and 434 nm. Furthermore, PL spectrum of colloidal solution exhibits additional green and red emission bands at 535, 570 and 622 nm. To explain the mechanism of PL emission in CdS NPs, trapping and radiative recombination levels have been identified and the corresponding energy band diagrams are suggested. Annealing process results in an overall enhancement in PL intensity due to the improvement in crystallinity associated with the reduction of nonradiative surface state defects. Irradiation of CdS NPs colloidal solution at UV irradiation dose <13 J cm−2 leads to the enhancement of PL quantum efficiency and blue shift of Eg(i.e. photo-brightening) due to the decrease in the particle size deduced from Brus equation (D), This behavior is due to UV irradiation effects suchas photopolymerization, the formation of CdSO4 passivation layers due to photooxidation and the reduction in DBrus by photocorrosion process. At UV irradiation dose <13 J cm−2,PL emission intensity continuously enhances without any change in both Eg and D. This
behavior is discussed in terms of electron filling model. Boltzmann curve fitting successfully describes the dependence of both DBrus and Eg on UV irradiation dose.

Cubic ZnxCd1−xS nanoparticles (NPs) synthesized by chemical precipitation method with average crystallite size of 2.9 ± 0.2 nm were characterized using X-ray diffraction (XRD), X-ray fluorescence (XRF), high-resolution
transmission electron microscope (HRTEM), UV–vis absorption, Fourier transform infrared red (FTIR), photoluminescence (PL) emission and Raman spectroscopy. XRD analysis demonstrated systematic shift of diffraction peaks to higher diffraction angles accompanied by a decrease in the lattice parameters with increasing Zn content (x); this confirmed the formation and homogeneity of ZnxCd1−xS nanoalloys. In addition, the dependence of lattice parameters and Raman shift on x showed linear behavior and good agreement
with Vegard's law. TEM images of ZnxCd1−xS NPs revealed nearly spherical shape NPs, relatively narrow particle size distribution and standard deviation in the range 1.8–3.4%.; as well as HRTEM images showed
well resolved diffraction crystalline planes of zinc-blende cubic type structure. Analysis of optical absorption
spectra showed blue shift of both the direct optical band gap from 3.25 to 4.05 eV and excitonic absorption
shoulder from 2.56 to 3.88 eV with increasing x, confirming the homogeneity of ZnxCd1−xS alloyed semiconductor
NPs. At excitation wavelength 325 nm, the deconvoluted structural defects related PL emission bands
are broadened and revealed stronger PL intensity than that at 370 nm. Furthermore, increasing x resulted in
PL enhancement accompanied by blue shift of green emission band centered at 515 nm–445 nm. To explain
composition dependent PL emission process; trapping and recombination localized levels in ZnxCd1−xS alloyed
NPs were identified quantitatively and an energy band diagram was suggested.

Cubic ZnxCd1−xS nanoparticles (NPs) synthesized by chemical precipitation method with average crystallite size of 2.9 ± 0.2 nm were characterized using X-ray diffraction (XRD), X-ray fluorescence (XRF), high-resolution
transmission electron microscope (HRTEM), UV–vis absorption, Fourier transform infrared red (FTIR), photoluminescence (PL) emission and Raman spectroscopy. XRD analysis demonstrated systematic shift of diffraction peaks to higher diffraction angles accompanied by a decrease in the lattice parameters with increasing Zn content (x); this confirmed the formation and homogeneity of ZnxCd1−xS nanoalloys. In addition, the dependence of lattice parameters and Raman shift on x showed linear behavior and good agreement
with Vegard's law. TEM images of ZnxCd1−xS NPs revealed nearly spherical shape NPs, relatively narrow particle size distribution and standard deviation in the range 1.8–3.4%.; as well as HRTEM images showed
well resolved diffraction crystalline planes of zinc-blende cubic type structure. Analysis of optical absorption
spectra showed blue shift of both the direct optical band gap from 3.25 to 4.05 eV and excitonic absorption
shoulder from 2.56 to 3.88 eV with increasing x, confirming the homogeneity of ZnxCd1−xS alloyed semiconductor
NPs. At excitation wavelength 325 nm, the deconvoluted structural defects related PL emission bands
are broadened and revealed stronger PL intensity than that at 370 nm. Furthermore, increasing x resulted in
PL enhancement accompanied by blue shift of green emission band centered at 515 nm–445 nm. To explain
composition dependent PL emission process; trapping and recombination localized levels in ZnxCd1−xS alloyed
NPs were identified quantitatively and an energy band diagram was suggested.

Cubic ZnxCd1−xS nanoparticles (NPs) synthesized by chemical precipitation method with average crystallite size of 2.9 ± 0.2 nm were characterized using X-ray diffraction (XRD), X-ray fluorescence (XRF), high-resolution
transmission electron microscope (HRTEM), UV–vis absorption, Fourier transform infrared red (FTIR), photoluminescence (PL) emission and Raman spectroscopy. XRD analysis demonstrated systematic shift of diffraction peaks to higher diffraction angles accompanied by a decrease in the lattice parameters with increasing Zn content (x); this confirmed the formation and homogeneity of ZnxCd1−xS nanoalloys. In addition, the dependence of lattice parameters and Raman shift on x showed linear behavior and good agreement
with Vegard's law. TEM images of ZnxCd1−xS NPs revealed nearly spherical shape NPs, relatively narrow particle size distribution and standard deviation in the range 1.8–3.4%.; as well as HRTEM images showed
well resolved diffraction crystalline planes of zinc-blende cubic type structure. Analysis of optical absorption
spectra showed blue shift of both the direct optical band gap from 3.25 to 4.05 eV and excitonic absorption
shoulder from 2.56 to 3.88 eV with increasing x, confirming the homogeneity of ZnxCd1−xS alloyed semiconductor
NPs. At excitation wavelength 325 nm, the deconvoluted structural defects related PL emission bands
are broadened and revealed stronger PL intensity than that at 370 nm. Furthermore, increasing x resulted in
PL enhancement accompanied by blue shift of green emission band centered at 515 nm–445 nm. To explain
composition dependent PL emission process; trapping and recombination localized levels in ZnxCd1−xS alloyed
NPs were identified quantitatively and an energy band diagram was suggested.

This work reports the synthesis of Mn-doped ZnO nanostructures using ice-bath assisted sonochemical technique. The impact of Mn-doping on structural, morphological, optical, and magnetic properties of ZnO nanostructures is studied. The morphological study shows that the lower doped samples possess mixtures of nanosheets and nanorods while the increase in Mn content leads to improvement of an anisotropic growth in a preferable orientation to form well-defined edge rods at Mn content of 0.04. UV–vis absorption spectra show that the exciton peak in the UV region is blue shifted due to Mn incorporation into the ZnO lattice. Doping ZnO with Mn ions leads to a reduction in the PL intensity due to a creation of more non-radiative recombination centers. The magnetic measurements show that the Mn-doped ZnO nanostructures exhibit ferromagnetic ordering at room temperature, as well as variation of the Mn content can significantly affect the ferromagnetic behavior of the samples.

This work reports the synthesis of Mn-doped ZnO nanostructures using ice-bath assisted sonochemical technique. The impact of Mn-doping on structural, morphological, optical, and magnetic properties of ZnO nanostructures is studied. The morphological study shows that the lower doped samples possess mixtures of nanosheets and nanorods while the increase in Mn content leads to improvement of an anisotropic growth in a preferable orientation to form well-defined edge rods at Mn content of 0.04. UV–vis absorption spectra show that the exciton peak in the UV region is blue shifted due to Mn incorporation into the ZnO lattice. Doping ZnO with Mn ions leads to a reduction in the PL intensity due to a creation of more non-radiative recombination centers. The magnetic measurements show that the Mn-doped ZnO nanostructures exhibit ferromagnetic ordering at room temperature, as well as variation of the Mn content can significantly affect the ferromagnetic behavior of the samples.