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.

In this paper, we investigate the effect of thermally induced structural phase transitions on the photoluminescence (PL) and optical absorption behaviour of Zn0.45Cd0.55S nanoparticles (NPs). Analysis of X-ray diffraction (XRD) patterns and high-resolution electron microscope (HRTEM) images reveal that the as-synthesized sample possesses zinc-blende-type cubic structure. In addition, at annealing temperature (Ta) 400 °C, the cubic structure transforms completely into the wurtzite-type hexagonal structure. Furthermore, the second phase transition of the as-synthesized sample has observed at 700 °C, where the cubic structure has transformed into mixed polycrystalline phases of hexagonal ZnO, cubic CdO, monoclinic CdSO3, and orthorhombic ZnSO4 structures. These new phases have also confirmed from the analysis of Raman and FTIR spectra. Analysis of UV–visible optical absorption spectra demonstrates that Increasing Ta results in the decrease of optical band gap due the improvement in crystallinity accompanied by the increase in the particle size. The PL emission bands at an excitation energy of 3.818 eV exhibit redshift and a decrease in the intensity with increasing Ta up to 500 °C. Meanwhile, further increase in Ta up to 700 °C results in the enhancement of green emission intensity. On the other hand, PL emission spectra at 3.354 eV and Ta 700 °C, reveal a dramatic increase in the emission intensity nearly by one-order of magnitude with respect to its value of the as-synthesized sample. This behaviour is ascribed to the incorporation of oxygen-related defects via thermal annealing in air, which act as additive radiative centers. Also, we have interpreted the observed spectral blue shift of PL emission spectrum with increasing excitation energy.

In this paper, we investigate the effect of thermally induced structural phase transitions on the photoluminescence (PL) and optical absorption behaviour of Zn0.45Cd0.55S nanoparticles (NPs). Analysis of X-ray diffraction (XRD) patterns and high-resolution electron microscope (HRTEM) images reveal that the as-synthesized sample possesses zinc-blende-type cubic structure. In addition, at annealing temperature (Ta) 400 °C, the cubic structure transforms completely into the wurtzite-type hexagonal structure. Furthermore, the second phase transition of the as-synthesized sample has observed at 700 °C, where the cubic structure has transformed into mixed polycrystalline phases of hexagonal ZnO, cubic CdO, monoclinic CdSO3, and orthorhombic ZnSO4 structures. These new phases have also confirmed from the analysis of Raman and FTIR spectra. Analysis of UV–visible optical absorption spectra demonstrates that Increasing Ta results in the decrease of optical band gap due the improvement in crystallinity accompanied by the increase in the particle size. The PL emission bands at an excitation energy of 3.818 eV exhibit redshift and a decrease in the intensity with increasing Ta up to 500 °C. Meanwhile, further increase in Ta up to 700 °C results in the enhancement of green emission intensity. On the other hand, PL emission spectra at 3.354 eV and Ta 700 °C, reveal a dramatic increase in the emission intensity nearly by one-order of magnitude with respect to its value of the as-synthesized sample. This behaviour is ascribed to the incorporation of oxygen-related defects via thermal annealing in air, which act as additive radiative centers. Also, we have interpreted the observed spectral blue shift of PL emission spectrum with increasing excitation energy.

In this paper, we investigate the effect of thermally induced structural phase transitions on the photoluminescence (PL) and optical absorption behaviour of Zn0.45Cd0.55S nanoparticles (NPs). Analysis of X-ray diffraction (XRD) patterns and high-resolution electron microscope (HRTEM) images reveal that the as-synthesized sample possesses zinc-blende-type cubic structure. In addition, at annealing temperature (Ta) 400 °C, the cubic structure transforms completely into the wurtzite-type hexagonal structure. Furthermore, the second phase transition of the as-synthesized sample has observed at 700 °C, where the cubic structure has transformed into mixed polycrystalline phases of hexagonal ZnO, cubic CdO, monoclinic CdSO3, and orthorhombic ZnSO4 structures. These new phases have also confirmed from the analysis of Raman and FTIR spectra. Analysis of UV–visible optical absorption spectra demonstrates that Increasing Ta results in the decrease of optical band gap due the improvement in crystallinity accompanied by the increase in the particle size. The PL emission bands at an excitation energy of 3.818 eV exhibit redshift and a decrease in the intensity with increasing Ta up to 500 °C. Meanwhile, further increase in Ta up to 700 °C results in the enhancement of green emission intensity. On the other hand, PL emission spectra at 3.354 eV and Ta 700 °C, reveal a dramatic increase in the emission intensity nearly by one-order of magnitude with respect to its value of the as-synthesized sample. This behaviour is ascribed to the incorporation of oxygen-related defects via thermal annealing in air, which act as additive radiative centers. Also, we have interpreted the observed spectral blue shift of PL emission spectrum with increasing excitation energy.

The crystallite size of commercial ZnO nanocrystals was tuned from 22.5 to 13.8 nm by ball-milling technique. X-ray diffraction patterns of mechanically milled ZnO nanocrystals reveal that milled samples possess the wurtzite-type hexagonal structure of ZnO. Increasing milling time results in the decrease of crystallite size and reduction of lattice parameters
due to a slight increase of internal compressive strain and dislocation density. Scanning electron microscope images demonstrate the appearance of large agglomerated particles with ambiguous edges due to large aggregation tendency with slight variation in the particle size at milling time 8 h. Analysis of the optical absorption spectra at different milling
time indicates the blue shift of exciton absorption peak and optical gap photoluminescence spectra reveal that mechanical milling of ZnO NCs leads to quenching of emission intensity due to the creation of nonradiative centers via increasing thermal strain and mechanical deformation produced during the milling process.

The crystallite size of commercial ZnO nanocrystals was tuned from 22.5 to 13.8 nm by ball-milling technique. X-ray diffraction patterns of mechanically milled ZnO nanocrystals reveal that milled samples possess the wurtzite-type hexagonal structure of ZnO. Increasing milling time results in the decrease of crystallite size and reduction of lattice parameters
due to a slight increase of internal compressive strain and dislocation density. Scanning electron microscope images demonstrate the appearance of large agglomerated particles with ambiguous edges due to large aggregation tendency with slight variation in the particle size at milling time 8 h. Analysis of the optical absorption spectra at different milling
time indicates the blue shift of exciton absorption peak and optical gap photoluminescence spectra reveal that mechanical milling of ZnO NCs leads to quenching of emission intensity due to the creation of nonradiative centers via increasing thermal strain and mechanical deformation produced during the milling process.

The crystallite size of commercial ZnO nanocrystals was tuned from 22.5 to 13.8 nm by ball-milling technique. X-ray diffraction patterns of mechanically milled ZnO nanocrystals reveal that milled samples possess the wurtzite-type hexagonal structure of ZnO. Increasing milling time results in the decrease of crystallite size and reduction of lattice parameters
due to a slight increase of internal compressive strain and dislocation density. Scanning electron microscope images demonstrate the appearance of large agglomerated particles with ambiguous edges due to large aggregation tendency with slight variation in the particle size at milling time 8 h. Analysis of the optical absorption spectra at different milling
time indicates the blue shift of exciton absorption peak and optical gap photoluminescence spectra reveal that mechanical milling of ZnO NCs leads to quenching of emission intensity due to the creation of nonradiative centers via increasing thermal strain and mechanical deformation produced during the milling process.

In the present study, we investigate the excitation wavelength dependent photoluminescence (PL) behavior in Zn0.45Cd0.55S nanoparticles. The
deconvoluted PL emission bands for nanopowders and nanocolloids reveal noticeable spectral blue shift with decreasing lex accompanied by intensity
enhancement. This unusual behavioris explained in terms of selective particle size distribution in nanostructures, advancing of fast ionization process at short lex; and solvation process in polar solvent. In addition, we attributed the UV-induced PL intensity enhancement and blue shift of the optical gap to the reduction in particle size by photo-corrosion process associated with the improvement in the quantum size effect; surface modification due to cross-linkage improvement of capping molecules at NPs surface; the creation of new radiative centers and the formation of photo-passivation layers from ZnSO4 and CdSO4, and photo-enhanced oxygen adsorption on Zn0.45Cd0.55S nanoparticles surface.

In the present study, we investigate the excitation wavelength dependent photoluminescence (PL) behavior in Zn0.45Cd0.55S nanoparticles. The
deconvoluted PL emission bands for nanopowders and nanocolloids reveal noticeable spectral blue shift with decreasing lex accompanied by intensity
enhancement. This unusual behavioris explained in terms of selective particle size distribution in nanostructures, advancing of fast ionization process at short lex; and solvation process in polar solvent. In addition, we attributed the UV-induced PL intensity enhancement and blue shift of the optical gap to the reduction in particle size by photo-corrosion process associated with the improvement in the quantum size effect; surface modification due to cross-linkage improvement of capping molecules at NPs surface; the creation of new radiative centers and the formation of photo-passivation layers from ZnSO4 and CdSO4, and photo-enhanced oxygen adsorption on Zn0.45Cd0.55S nanoparticles surface.