Nano Research
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2024
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IF 9.5
Yan Danni,Dong Yuhui,Wei Naiwei,Yang Shuai,Zhu Hong,Gu Wanzhong,Zou Yousheng,Zeng Haibo
Quaternary Ag-In-Ga-S (AIGS) quantum dot (QD) is considered a promising, spectral-tunable, and environmentally friendly luminescent display material. However, the more complex surface defect states of AIGS QDs resulting from the coexistence of multiple elements lead to a low (< 60%) photoluminescence quantum yield (PLQY). Here, we develop a novel convenient method to introduce Z-type ligands ZnX 2 (X = Cl, Br, I) for passivating the surface defects of AIGS QDs to dramatically enhance the PLQY and stability without affecting the crystalline structure and morphology. Results show that the addition of ZnCl 2 during the purified process of AIGS QDs leads to a 3-fold increase of PLQY (from 28.5% to 87%). Impressively, the highest PLQY is up to a recorded value of 92%, which is comparable to typical heavy metal QDs. Exciton dynamics studies have shown that the rapid annihilation process of excitons in treated QDs is inhibited. We also confirm that the improvement in PLQY is a result of the effective passivation of the non-coordinating atom on the QD surface by building a new bonding between sulfur dangling and Zn 2+ . The realization of high PLQY will further promote the application of AIGS QDs in luminescent displays.
研究领域:
材料科学
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纳米技术
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光电技术
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DOI
高影响因子
ChemNanoMat
·
2024
·
IF 2.6
Haibo Zeng,Shuai Yang,Danni Yan,Hong Zhu,Naiwei Wei,Yuhui Dong,Yousheng Zou
In recent years, Ag-In-Ga-S (AIGS) quaternary quantum dots (QDs) have garnered significant attention as a novel class of environmentally friendly and non-toxic QDs. However, the hydrothermal synthesis method for aqueous QDs has been plagued by issues such as inconsistent size, subpar crystallinity, and low photoluminescence quantum yield (PLQY). Herein, we developed a dual ligand strategy based on the hard and soft acids and bases (HSAB) theory to synthesize aqueous AIGS QDs with an impressive PLQY of up to 64.3%, currently the highest value among hydrothermal-synthesized uncoated I-III-VI QDs. The QDs exhibit better crystallinity, narrow size distribution (3.07 ± 0.31 nm), and remarkable stability. The mechanism underlying this dual ligand strategy was further elucidated, shedding light on the distinct influences of different ligands on the growth of QDs. The high PLQY contributes to the further application of aqueous AIGS QDs in luminescent displays and the field of biology. Meanwhile, this ligand strategy has broad reference significance for efficient preparation of other water-soluble QDs.
研究领域:
材料科学
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纳米技术
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化学
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光电技术
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生物技术
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DOI
高影响因子
ACS Applied Materials & Interfaces
·
2023
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IF 9.5
Shuai Zhang,Linxiang Yang,Gaoyu Liu,Shengli Zhang,Qingsong Shan,Haibo Zeng
I–III–VI quantum dots (QDs) and derivatives (I, III, and VI are Ag+/Cu+, Ga3+/In3+, and S2–/Se2–, respectively) are the ideal candidates to replace II–VI (e.g., CdSe) and perovskite QDs due to their nontoxicity, pure color, high photoluminescence quantum yield (PLQY), and full visible coverage. However, the chaotic cation alignment in multielement systems can easily lead to the formation of multiple surface vacancies, highlighted as VI and VVI, leading to nonradiative recombination and nonequilibrium carrier distribution, which severely limit the performance improvement of materials and devices. Here, based on Zn–Ag–In–Ga–S QDs, we construct an ultrathin indium sulfide shell that can passivate electron vacancies and convert donor/acceptor level concentrations. The optimized In-rich 2-layer indium sulfide structure not only enhances the radiative recombination rate by preventing further VS formation but also achieves the typical DAP emission enhancement, achieving a significant increase in PLQY to 86.2% at 628 nm. Moreover, the optimized structure can mitigate the lattice distortion and make the carrier distribution in the interior of the QDs more balanced. On this basis, red QD light-emitting diodes (QLEDs) with the highest external quantum efficiency (EQE; 5.32%) to date were obtained, providing a novel scheme for improving I–III–VI QD-based QLED efficiency.
研究领域:
材料科学
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纳米技术
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光电子学
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光子学
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DOI
PubMed
高影响因子
ACS Nano
·
2026
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IF 16
Xiulin Xie,Gaoyu Liu,Yu Zhang,Yiqing Yang,Wentao Niu,Ouyang Lin,Yangyang Bian,Jin Lu,Shengli Zhang,Aiwei Tang
I–III–VI group semiconductor nanocrystals (NCs) with narrow-bandwidth emission have emerged as promising candidates for display technologies due to their tunable emission wavelength and eco-friendly composition. Herein, Ga-rich Ag–In–Ga–S (AIGS) NCs exhibited a narrow photoluminescence emission with a full width at half maximum (fwhm) of 29 nm, which was derived from In-rich Ag–In–Ga–S NCs with an fwhm of 113 nm via a cation exchange strategy. The evolution process was studied systematically using steady- and transient-state spectroscopic techniques, revealing that the narrow photoluminescence (PL) bandwidth primarily originated from free-to-bound radiative recombination. The result was consistent with first-principles calculations. Furthermore, the electroluminescent devices based on AIGS NCs showed a record narrow electroluminescent bandwidth of less than 30 nm, and the maximum external quantum efficiency (EQE) could reach up to 1.2%.
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PubMed
高影响因子
Nanoscale
·
2024
·Vol. 16
·期 9
·4591-4599
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IF 5.8
Ouyang Lin,Lijin Wang,Xiulin Xie,Shuaibing Wang,Yibo Feng,Jiawen Xiao,Yu Zhang,Aiwei Tang
Silver-based I–III–VI-type semiconductor nanocrystals have received extensive attention due to their narrow-band luminescence properties. Herein, we demonstrated a seed-mediated growth of quaternary Ag–In–Ga–S (AIGS) nanocrystals (NCs) with narrow-band luminescence. By conducting partial cation exchange with In3+ and Ga3+ based on Ag2S NCs and controlling the Ag/In feeding ratios (0.25 to 2) of Ag–In–S seeds as well as the inventory of 1-dodecanethiol, we achieved optimized luminescence performance in the synthesized AIGS NCs, characterized by a narrow full width at half maximum of less than 40 nm. Meanwhile, narrow-band luminescent AIGS NCs exhibit a tetragonal AgGaS2 crystal structure and a gradient alloy structure, rather than a core–shell structure. Most importantly, the kinetics decay curves of time-resolved photoluminescence and the ground state bleaching in transient absorption generally agree with each other regarding the lifetime of the second decay component, which indicates that the narrow-band luminescence is due to the slow radiative recombination between trapped electrons and trapped holes located at the edge of the conduction band and the deep silver-related trap states (e.g., silver vacancy), respectively. This study provides new insights into the correlation between the narrow-band luminescence properties and the structural characteristics of AIGS NCs.
研究领域:
材料科学
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光学
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DOI
PubMed
高影响因子
ACS Photonics
·
2026
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IF 6
Yujia Luo,Yikun He,Yuyao Feng,Wanzhong Gu,Wanling Mao,Yixuan He,Liang Ke,Yuhui Dong,Yousheng Zou
Eco-friendly Ag–In–Ga–S (AIGS) quantum dots (QDs) are potential alternatives in white light-emitting diodes (WLEDs) due to their high photoluminescence quantum yield (PLQY) and tunable emission. The conventional stacked-film structure using multicomponent QDs suppresses reabsorption losses among different color QDs, but inevitably introduces interfacial optical losses and manufacturing complexity and cost. In this study, a single color-conversion blended film with uniform and excellent luminescence is fabricated using high-PLQY red-emitting (85%) and green-emitting (91%) AIGS QDs simultaneously incorporated into a PMMA matrix. This deliberately utilizes reabsorption governed by the relative ratio between red and green QDs rather than solely suppressing it, thereby eliminating interfacial losses and enhancing luminance, which results in higher photoluminescence emission while maintaining a nearly identical low blue-light transmittance. Furthermore, the blended-film WLED fabricated by integrating the blended film with a blue LED chip exhibited a higher luminance (532.3 cd/m2), representing a greater than 25-fold increase over the conventional stacked-film device (21.0 cd/m2). The blended-film WLED achieved CIE chromaticity coordinates of (0.31, 0.32) and a color rendering index (CRI) of 87.3. The study provides a better understanding of reabsorption in single-layer multicolor QD films and promotes the development of simple and efficient I–III–VI QD backlight films for white-light display applications.
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高影响因子
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