An aqueous solution of fluorescent MoS2 quantum dots toward a sensitive and selective probe for Fe3+: A tri-mode spectroscopic sensing technique

Ali, Mir Sahanur; Ali, Mir Sahidul; Bhunia, Nayan; Mallik, Abhijit; Dutta, Kingshuk; Karmakar, Srinibas; Mukherjee, Prasun; Chattopadhyay, Dipankar

doi:10.1016/j.jpcs.2023.111261

Cited by 8 publications

(4 citation statements)

References 53 publications

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“…The time-resolved PL decay profiles of MoS 2 dots are shown in Figure for two emission wavelengths (420 and 470 nm) on excitation at 340 nm. The observed intensity profiles I ( t ) follows a multiexponential decay scheme as I false( t false) = ∑ i = 1 3 α i e − t / τ i Here, τ i is the decay time and α i is the corresponding amplitude. − The PL decay has three components with lifetimes of 1.07, 4.75, and 15.64 ns (for λ em = 420 nm). For λ em = 470 nm, the lifetime components are 0.77, 3.21, and 9.88 ns.…”

Section: Resultsmentioning

confidence: 99%

Mixed Phase MoS₂ Quantum Dots as Optical Limiters for Ultrafast Lasers

Sirohi,

Jaiswal,

Bisht

2024

ACS Appl. Nano Mater.

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Quantum dots of MoS 2 synthesized via the method of laser ablation show a mixed phase of 2H and 1T polytypes with a lateral size of 2−7 nm. The photoluminescence spectra exhibit prominent dependence on the energy of the incident photon. This observation indicates a distribution of energy bandgap and the presence of differently sized dots. This is also supported by the energy-dependent decay rates. The z-scan technique and optical phase conjugation geometry of degenerate four wave mixing are used to estimate the nonlinear optical parameters. The change in nonlinear optical response of the dots with the pump wavelength is also investigated. The mechanisms of two-photon absorption, electrostriction, free carrier refraction, free carrier absorption, and nonlinear scattering along with the laser-induced thermal effects are found to contribute to the nonlinear response. The effect of the mixed phase and nonzero direct bandgap, achieved via the quantum confinement effect, on the observed nonlinear optical response is discussed. The prepared dots show good optical limiting capabilities, which make them a promising candidate for designing protective coatings for high power lasers.

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Section: Resultsmentioning

confidence: 99%

Mixed Phase MoS₂ Quantum Dots as Optical Limiters for Ultrafast Lasers

Sirohi,

Jaiswal,

Bisht

2024

ACS Appl. Nano Mater.

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“…There are hundreds of papers on the synthesis of quantum dots from different precursors. This includes reagent-grade materials, 9,10 waste materials, 11,12 and natural precursors. 13,14 When speaking of its applications, QDs have been widely used in the detection of different chemical species.…”

Section: Sourav Duttamentioning

confidence: 99%

Advances in the ratiometric combination of quantum dots for their use in sensing applications

Santra¹,

Dutta²,

Adalder³

2023

Mater. Adv.

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“…The reduction in size in all dimensions in QDs is expected to significantly enhance the optical properties as compared to the monolayer (PLQY ≈ 10 –3 %) due to strong quantum confinement of charge carriers, resulting in a large number of exciton generation. The enhanced optical properties of MoS 2 QDs make them highly suitable for application in optoelectronic devices such as photodetectors, , optical sensors, − electrochromic devices, and light-emitting diodes (LEDs) . The toxicity of QDs such as CdSe, PbS, and CdS curtails their usage in biomedical applications, while the low toxicity MoS 2 QDs is a good substitute. − Apart from enhanced optical properties, the increase in surface-to-volume ratio enables these QDs to find application in catalysis , and energy storage devices such as supercapacitors. − There are other materials in transition metal dichalcogenide family such as WS 2 and MoSe 2 with a bandgap larger than MoS 2 . , A detailed study of optical properties of MoS 2 QDs will be beneficial for optimization of PLQY of these similar structured materials also. − …”

Section: Introductionmentioning

confidence: 99%

Enhanced Photoluminescence Quantum Yield of Colloidal MoS₂ Quantum Dots by Optimization of Oleic Acid and Oleylamine for Light-Emitting Diode Applications

Lambora,

Bhardwaj

2024

ACS Appl. Nano Mater.

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In this study, we investigate the impact of oleic acid and oleylamine on the photoluminescence quantum yield (PLQY) and size distribution of MoS 2 quantum dots (QDs) synthesized by using the colloidal heating method. The optical characteristics of MoS 2 QDs are found to be dependent on OAc/OAm (mL/mL) concentrations, which are (0 mL/0 mL), (0 mL/3 mL), (3 mL/0 mL), (3 mL/3 mL), (3 mL/6 mL), and (6 mL/3 mL). The optimal amount of OAc is obtained to be 3 mL with a high PLQY and narrow size distribution of QDs with an average diameter of ≈3 nm. A maximum PLQY of 12.32% is measured for (3 mL/0 mL) QDs with blue emission showing PL maxima at ≈440 nm, while for (3 mL/3 mL) and (3 mL/6 mL), the measured PLQY values are 9.12 and 7.00%, respectively. For the remaining OAc/ OAm combinations, the measured PLQY value is ≈3% with wide-size distributions. Morphological analysis using a transmission electron microscope reveals the spherical QD formation for all the different OAc/OAm combinations. FTIR results show the presence of C−H, C�O, C�C, and C−N, confirming OAc and OAm coverage on the MoS 2 QD surface. We report the highest achieved PLQY of 12.32% for colloidally synthesized blue-emitting MoS 2 QDs. With high PLQY, these QDs can find applications in light-emitting diode fabrication, sensing, and bioimaging.

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An aqueous solution of fluorescent MoS2 quantum dots toward a sensitive and selective probe for Fe3+: A tri-mode spectroscopic sensing technique

Cited by 8 publications

References 53 publications

Mixed Phase MoS₂ Quantum Dots as Optical Limiters for Ultrafast Lasers

Mixed Phase MoS₂ Quantum Dots as Optical Limiters for Ultrafast Lasers

Advances in the ratiometric combination of quantum dots for their use in sensing applications

Enhanced Photoluminescence Quantum Yield of Colloidal MoS₂ Quantum Dots by Optimization of Oleic Acid and Oleylamine for Light-Emitting Diode Applications

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An aqueous solution of fluorescent MoS2 quantum dots toward a sensitive and selective probe for Fe3+: A tri-mode spectroscopic sensing technique

Cited by 8 publications

References 53 publications

Mixed Phase MoS2 Quantum Dots as Optical Limiters for Ultrafast Lasers

Mixed Phase MoS2 Quantum Dots as Optical Limiters for Ultrafast Lasers

Advances in the ratiometric combination of quantum dots for their use in sensing applications

Enhanced Photoluminescence Quantum Yield of Colloidal MoS2 Quantum Dots by Optimization of Oleic Acid and Oleylamine for Light-Emitting Diode Applications

Contact Info

Product

Resources

About

Mixed Phase MoS₂ Quantum Dots as Optical Limiters for Ultrafast Lasers

Mixed Phase MoS₂ Quantum Dots as Optical Limiters for Ultrafast Lasers

Enhanced Photoluminescence Quantum Yield of Colloidal MoS₂ Quantum Dots by Optimization of Oleic Acid and Oleylamine for Light-Emitting Diode Applications