Structural, band gap and photoluminescence behaviour of Mn-doped ZnS quantum dots annealed under Ar atmosphere

Sakthivel, P.; Muthukumaran, S.; Ashokkumar, Muthupandian

doi:10.1007/s10854-014-2572-0

Cited by 43 publications

(18 citation statements)

References 43 publications

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“…Furthermore, the presence of Mn 2+ in IL-modified DE-QDC was verified by an X-ray photoelectron spectroscopic (XPS) studywhich was performed using an Omicron Nanotechnology X-ray photoelectron spectrometer with Al Kα source (10 mA, 15 kV). The witnessed binding energy peaks at 639.6 and 654.6 eVwhich are similar to the binding energies of 2P 3/2 and 2p 1/2 of Mn 2+ , which exists as a dopant in the QD of IL-modified DE-QDC (Figure S8, Supporting Information), − while the binding energy peaks at 1021.4 and 1044.6 eVwhich are due to 2P 3/2 and 2p 1/2 levels of Zn 2+ , respectively, and matches with the binding energy of Zn–Sclearly confirmed the existence of host Zn 2+ (Figure S8, Supporting Information). − Thus, the preservation of the oxidation states of dopant Mn 2+ and host Zn 2+ of QDs, following dual surface modification, was noticed.…”

Section: Resultssupporting

confidence: 54%

“…The witnessed binding energy peaks at 639.6 and 654.6 eVwhich are similar to the binding energies of 2P 3/2 and 2p 1/2 of Mn 2+ , which exists as a dopant in the QD of IL-modified DE-QDC (Figure S8, Supporting Information), − while the binding energy peaks at 1021.4 and 1044.6 eVwhich are due to 2P 3/2 and 2p 1/2 levels of Zn 2+ , respectively, and matches with the binding energy of Zn–Sclearly confirmed the existence of host Zn 2+ (Figure S8, Supporting Information). − Thus, the preservation of the oxidation states of dopant Mn 2+ and host Zn 2+ of QDs, following dual surface modification, was noticed. In a nutshell, this is the first report showing the postsynthesis surface modification of a DE-QDC nanocomposite, consisting of an orange luminescent Mn 2+ -doped ZnS QD and green luminescent zinc quinolate complex, using a blue-emitting choline tosylate IL and making an IL-modified DE-QDC a better and new WLE composite compared to only DE-QDC and other reported WLE materials (Table S6 Supporting Information).…”

Section: Resultssupporting

confidence: 54%

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Surface Modification of Dual-Emitting Quantum Dot Complex by Ionic Liquid for Bright and Stable White-Light Emission

Manna

Pramanik

Bhandari

2022

ACS Appl. Nano Mater.

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Herein we report the postsynthesis surface modification of a dual-emitting quantum dot complex (DE-QDC) nanocomposite, consisting of an orange-emitting quantum dot (QD) and green-emitting inorganic complex, using a blue-emitting ionic liquid (IL). The IL-modified DE-QDC showed the concurrent tunable tricolor emission-based bright and stable white-light emission, with chromaticity of (0.32, 0.32), color rendering index of 86, and correlated color temperature of 6176 K. Importantly, the solid form of IL-modified DE-QDC displayed the preservation of white-light nature and structure of QD and was found to be stable for their long-term use.

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Section: Resultssupporting

confidence: 54%

Section: Resultssupporting

confidence: 54%

Surface Modification of Dual-Emitting Quantum Dot Complex by Ionic Liquid for Bright and Stable White-Light Emission

Manna

Pramanik

Bhandari

2022

ACS Appl. Nano Mater.

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“…According to this theory, as the particle size decreases, the electrons in the valence band and the holes in the conduction band confine themselves within a space having a dimension of the de Broglie wavelength. However, this confinement influences the quantization of the energy and the momentum of the corresponding carriers and also enhances the optical transition energy between the valence band and the conduction band resulting in a broad band gap [32]. Figure 15 displays the UV visible transmittance spectrum of ZnO A NPs and ZnO B NPs.…”

Section: Optical Analysismentioning

confidence: 99%

Synthesis of ZnO nanoparticles by two different methods & comparison of their structural, antibacterial, photocatalytic and optical properties

et al. 2020

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In this work, two different methods (sol-gel and biosynthesis) were adopted for the synthesis of zinc oxide (ZnO) nanoparticles. The leaf extract of Azadirachta Indica (Neem) was utilized in the biosynthesis scheme. Structural, antibacterial, photocatalytic and optical performances of the two variants were analyzed. Both variants demonstrated a wurtzite hexagonal structure. The biosynthesized variant (25.97 nm) exhibited smaller particles than that of the sol-gel variant (33.20 nm). The morphological analysis revealed that most of the particles of the sol-gel variant remained within the range of 15 nm to 68 nm while for the biosynthesized variant the range was 10-70 nm. The antibacterial assessment was redacted by using the agar well diffusion method in which the bacteria medium was Escherichia coli O157: H7. The zone of inhibition of bacterial growth was higher in the biosynthesized variant (14.5 mm). The photocatalytic performances of the nanoparticles were determined through the degradation of methylene blue dye in which the biosynthesized variant provided better performance. The electron spin resonance (EPR) analysis revealed that the free OH·radicals were the primary active species for this degradation phenomenon. The absorption band of the sol-gel and biosynthesized variants were 363 nm and 356 nm respectively. The optical band gap energy of the biosynthesized variant (3.25 eV) was slightly higher than that of the sol-gel variant (3.23 eV). Nevertheless, the improved antibacterial and photocatalytic responses of the biosynthesized variants were obtained due to the higher rate of stabilization mechanism of the nanoparticles by the organic chemicals (terpenoids) present in the Neem leaf extract.

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“…The lowering of the energy of the absorption edge (red shift) of the Ni 2+ samples, verified in Figure 4, suggests a transfer energy between Zn 2 TiO 4 host and d states of Ni 2+ ions 53 . Furthermore, a decrease in crystallite size indicates a degree of coupling of d orbitals of Ni 2+ with energy levels of the host 54 .…”

Section: Resultsmentioning

confidence: 64%

Photoluminescence, Photoacoustic and Structural Characteristics of Polycrystalline Zn2TiO4: Ni2+ Semiconductor

et al. 2020

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This work presents the investigation, at room temperature, of Zn 2 TiO 4 samples containing Ni 2+ ions as substitutional impurities. Samples with molecular formula Zn 2(1-x) Ni 2x TiO 4 , where x = 0.00, 0.0007, 0.001, 0.0013, 0.002 and 0.003, in which Zn 2+ ions were replaced by Ni 2+ ions, were prepared through solid-state method, crystalline data were obtained by X-ray diffraction, the elemental composition was determined by X-ray fluorescence and the optical properties were investigated through photoluminescence and photoacoustic techniques. The photoluminescence spectra showed broadbands from 640 nm to 800 nm. The emission of the Zn 2(1-x) Ni 2x TiO 4 samples was assigned to the overlapping of the Ni 2+ and the Zn 2 TiO 4 emission. The most intense photoluminescence signal was obtained with excitation radiation at a wavelength of 360 nm for the sample with x = 0.001. The photoacoustic spectra showed absorption bands characteristic of semiconductor materials due to the host Zn 2 TiO 4 . The energy bandgap of the Zn 2(1-x) Ni 2x TiO 4 was obtained from photoacoustic absorption spectra.

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Structural, band gap and photoluminescence behaviour of Mn-doped ZnS quantum dots annealed under Ar atmosphere

Cited by 43 publications

References 43 publications

Surface Modification of Dual-Emitting Quantum Dot Complex by Ionic Liquid for Bright and Stable White-Light Emission

Surface Modification of Dual-Emitting Quantum Dot Complex by Ionic Liquid for Bright and Stable White-Light Emission

Synthesis of ZnO nanoparticles by two different methods & comparison of their structural, antibacterial, photocatalytic and optical properties

Photoluminescence, Photoacoustic and Structural Characteristics of Polycrystalline Zn2TiO4: Ni2+ Semiconductor

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