Surface modification effects on defect-related photoluminescence in colloidal CdS quantum dots

Lee, TaeGi; Shimura, Kunio; Kim, DaeGwi

doi:10.1039/c7cp07812a

Cited by 23 publications

(12 citation statements)

References 24 publications

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“…These nanomaterials are photoactive, and potentially could be transformed by photoetching, as observed with other semiconducting nanoparticles. [21][22][23] Thus, it is critical to quantify the amounts of metal ions released from heavy metal-based nanoparticles during exposure to solar simulated irradiation.…”

Section: Introductionmentioning

confidence: 99%

Toxicity of nanomaterials due to photochemical degradation and the release of heavy metal ions

et al. 2020

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Section: Introductionmentioning

confidence: 99%

Toxicity of nanomaterials due to photochemical degradation and the release of heavy metal ions

et al. 2020

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“…The intensity-weighted average lifetime was obtained by the following equation

. The faster decay component τ 1 is generally associated to the surface traps and the slower decay component τ 2 to the excitonic transition in the InP core [ 36 , 37 , 38 ]. As listed in Table 3 , the average lifetimes are decreasing in the order of QD–OcSH, QD–PBSH, and QD–TP with 32.95 ns, 25.02 ns, and 12.25 ns, respectively.…”

Section: Resultsmentioning

confidence: 99%

Enhanced Electroluminescence via a Nanohybrid Material Consisting of Aromatic Ligand-Modified InP Quantum Dots and an Electron-Blocking Polymer as the Single Active Layer in Quantum Dot–LEDs

et al. 2022

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Electron overcharge causes rapid luminescence quenching in the quantum dot (QD) emission layer in QD light–emitting diodes (QD–LEDs), resulting in low device performance. In this paper we describe the application of different aromatic thiol ligands and their influence on device performance as well as their behavior in combination with an electron blocking material (EBM). The three different ligands, 1–octanethiol (OcSH), thiophenol (TP), and phenylbutan–1–thiol (PBSH), were introduced on to InP/ZnSe/ZnS QDs referred to as QD–OcSH, QD–TP, and QD–PBSH. PBSH is in particular applied as a ligand to improve QD solubility and to enhance the charge transport properties synergistically with EBM probably via π–π interaction. We synthesized poly-[N,N-bis[4-(carbazolyl)phenyl]-4-vinylaniline] (PBCTA) and utilized it as an EBM to alleviate excess electrons in the active layer in QD–LEDs. The comparison of the three QD systems in an inverted device structure without the application of PBCTA as an EBM shows the highest efficiency for QD–PBSH. Moreover, when PBCTA is introduced as an EBM in the active layer in combination with QD–PBSH in a conventional device structure, the current efficiency shows a twofold increase compared to the reference device without EBM. These results strongly confirm the role of PBCTA as an EBM that effectively alleviates excess electrons in the active layer, leading to higher device efficiency.

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“…For XPS measurements, the monolayer structures of CdTe and CdTe/CdS QDs were prepared as follows. 40 The Si substrates were cleaned by immersion in fresh piranha solution (1/3 (v/v) mixture of 30% H2O2 and 98% H2SO4) for 20 min. Subsequently, the substrates were rinsed with water and used immediately after cleaning.…”

Section: Methodsmentioning

confidence: 99%

Selective Hydrothermal Synthesis of Water-Soluble CdTe and CdTe/CdS Colloidal Quantum Dots by Controlling the Te/Cd Molar Ratio of the Precursor Solution

Shimura

Lee

Itô

et al. 2021

Bulletin of the Chemical Society of Japan

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During the synthesis of CdTe quantum dots (QDs) by the hydrothermal method, a CdS shell layer is naturally formed by the thermal decomposition of thiol ligands, and CdTe/CdS core/shell QDs are produced. Herein, we investigate the selective synthesis of CdTe and CdTe/CdS QDs to control the thermal decomposition of thiol ligands by changing the Te/Cd molar ratio of the precursor solutions. From the experimental results of X-ray photoelectron spectroscopy and optical properties of absorption and photoluminescence (PL) spectra and PL decay profiles of the synthesized colloidal QDs, it was found that the formation of the CdS shell can be controlled by varying the Te/Cd ratio of the precursor solution. Thus, the selective synthesis of CdTe and CdTe/CdS QDs with the same PL energy but different PL decay times is possible.

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Surface modification effects on defect-related photoluminescence in colloidal CdS quantum dots

Cited by 23 publications

References 24 publications

Toxicity of nanomaterials due to photochemical degradation and the release of heavy metal ions

Toxicity of nanomaterials due to photochemical degradation and the release of heavy metal ions

Enhanced Electroluminescence via a Nanohybrid Material Consisting of Aromatic Ligand-Modified InP Quantum Dots and an Electron-Blocking Polymer as the Single Active Layer in Quantum Dot–LEDs

Selective Hydrothermal Synthesis of Water-Soluble CdTe and CdTe/CdS Colloidal Quantum Dots by Controlling the Te/Cd Molar Ratio of the Precursor Solution

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