High efficiency blue light-emitting devices based on quantum dots with core-shell structure design and surface modification

Zhao, Bin; Chen, Li‐Xuan; Liu, Wenyong; Wu, Longjia; Lu, Zheming; Cao, Weiran

doi:10.1039/d0ra10173g

Cited by 11 publications

(7 citation statements)

References 24 publications

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“…TBP has been widely used in the synthesis of CdSe and other types of NCs [ 32 , 33 , 34 ]. However, there is uncertainty in terms of its influence on the crystal structure.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of CdSe and CdSe/ZnS Quantum Dots with Tunable Crystal Structure and Photoluminescent Properties

Zheng

et al. 2022

Nanomaterials

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Mastery over the structure of nanocrystals is a powerful tool for the control of their fluorescence properties and to broaden the range of their applications. In this work, the crystalline structure of CdSe can be tuned by the precursor concentration and the dosage of tributyl phosphine, which is verified by XRD, photoluminescence and UV-vis spectra, TEM observations, and time-correlated single photon counting (TCSPC) technology. Using a TBP-assisted thermal-cycling technique coupled with the single precursor method, core–shell QDs with different shell thicknesses were then prepared. The addition of TBP improves the isotropic growth of the shell, resulting in a high QY value, up to 91.4%, and a single-channel decay characteristic of CdSe/ZnS quantum dots. This work not only provides a facile synthesis route to precisely control the core–shell structures and fluorescence properties of CdSe nanocrystals but also builds a link between ligand chemistry and crystal growth theory.

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“…TBP has been widely used in the synthesis of CdSe and other types of NCs [ 32 , 33 , 34 ]. However, there is uncertainty in terms of its influence on the crystal structure.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of CdSe and CdSe/ZnS Quantum Dots with Tunable Crystal Structure and Photoluminescent Properties

Zheng

et al. 2022

Nanomaterials

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“…Due to the smaller molecular size of TBP ligands, they provide a higher surface coverage on the QDs. 89…”

Section: Classification Of Ligandsmentioning

confidence: 99%

“…Due to the smaller molecular size of TBP ligands, they provide a higher surface coverage on the QDs. 89 Researchers have conducted studies on alkyl phosphinemodified CsPbX 3 . For instance, the compound TOP can coordinate with Pb 2+ ions to establish P-Pb bonds.…”

Section: Alkyl Phosphatesmentioning

confidence: 99%

Ligand modification enhanced quantum dot LEDs: principles and methods

Dong¹,

Wang²,

Bu³

et al. 2023

J. Mater. Chem. C

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“…The benign characters of colloidal quantum dots (QDs), such as size-controlled optical band gap, high color-purity spectral properties, and near-unity photoluminescence quantum yield (PL QY), guarantee their promising applications in semiconductor optoelectronic devices. − In many of these applications, the QDs under an external electric field are subjected to spectral diffusion, − which is known to be due to the consequence of quantum confinement Stark effect (QCSE). On the other hand, the QCSE provides one way of modulating the wavelength shift and the fluctuation in PL intensity, which shows the feasibility as fluorescent sensors in biomedical applications. − …”

Section: Introductionmentioning

confidence: 99%

Effect of Electron–Hole Separation on the Spectral Diffusion of Small-Sized CdSe Quantum Dots under an External Electric Field

et al. 2023

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Spectral diffusion occurs in semiconductor quantum dots (QDs) under an external electric field, resulting from the transition energy shift of one single dot during optical absorption and emission processes. The classical electric polarization model fails to interpret the spectral diffusion in some cases when strong quantum confinement Stark effects and large Stokes shifts exist in the small-sized QDs. Based on the two-process (optical absorption and emission) four-state (the ground-and excited-states involved in each process) model, the field-induced spectral shifts of the (CdSe) 33 and (CdSe) 34 structures, which are computed with the first-principles calculations, are well fitted by the dipole moment and static polarizability changes in the separate processes. Furthermore, the linear and the quadratic variations of the field-induced spectral shifts are interpreted with the compressible and the incompressible electron−hole separation distances, which are computed from the Kohn−Sham levels involved in the excited states. Our study provides the direct pieces of evidence on the hypothesis summarized experimentally that the electron transition energy increases with the decreasing electron−hole separation. As a result, the spectral shifts of one single QD, as well as the spectral diffusion of QDs, are then adjustable by tuning the direction and strength of the external field.

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High efficiency blue light-emitting devices based on quantum dots with core-shell structure design and surface modification

Abstract: The exposed Se on QD surface causes non-radiative relaxations which results in a low PLQY. However, the PLQY was improved from less than 8.0% up to above 85.0% by adding tributyl phosphine which can terminate the dangling bonds of the Se.

Cited by 11 publications

References 24 publications

Synthesis of CdSe and CdSe/ZnS Quantum Dots with Tunable Crystal Structure and Photoluminescent Properties

Synthesis of CdSe and CdSe/ZnS Quantum Dots with Tunable Crystal Structure and Photoluminescent Properties

Ligand modification enhanced quantum dot LEDs: principles and methods

Effect of Electron–Hole Separation on the Spectral Diffusion of Small-Sized CdSe Quantum Dots under an External Electric Field

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