Nature Communications
·
2024
·Vol. 15
·期 1
·1-12
·
IF 14.7
Zhang Renfu,Zhou Qinqi,Huang Siyuan,Zhang Yiwen,Wen Rui-Tao
Ion trapping has been found to be responsible for the performance degradation in electrochromic oxide thin films, and a detrapping procedure was proved to be effective to rejuvenate the degraded films. Despite of the studies on ion trapping and detrapping, its dynamics remain largely unknown. Moreover, coloration mechanisms of electrochromic oxides are also far from clear, limiting the development of superior devices. Here, we visualize ion trapping and detrapping dynamics in a model electrochromic material, amorphous WO 3 . Specifically, formation of orthorhombic Li 2 WO 4 during long-term cycling accounts for the origin of shallow traps. Deep traps are multiple-step-determined, composed of mixed W 4+ -Li 2 WO 4 , amorphous Li 2 WO 4 and W 4+ -Li 2 O. The non-decomposable W 4+ -Li 2 WO 4 couple is the origin of the irreversible traps. Furthermore, we demonstrate that, besides the typical small polaron hopping between W 5+ ↔ W 6+ sites, bipolaron hopping between W 4+ ↔ W 6+ sites gives rise to optical absorption in the short-wavelength region. Overall, we provide a general picture of electrochromism based on polaron hopping. Ion trapping and detrapping were demonstrated to also prevail in other cathodic electrochromic oxides. This work not only provides the ion trapping and detrapping dynamics of WO 3 , but also open avenues to study other cathodic electrochromic oxides and develop superior electrochromic devices with great durability.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
NANOTECHNOLOGY
·
2022
·Vol. 33
·期 34
·345709
·
IF 3.953
Beibei Jia,Jun Zhou,Yuqing Chen,Zepeng Lv,Haomin Guo,Zixuan Zhang,Zihe Zhu,Haoyu Yu,Yang Wang,Kai Wu
Charge transport in insulating composites is fundamental to designing high performance in electrical breakdown strength processes. A fundamental understanding of the charge transport at nanoscale in insulating composites remains elusive. Herein, we fabricate two types of interfaces in epoxy (EP) composites (Al2O3/EP and bubble/EP, respectively). Then the local dynamic charge mobility behavior and charge density are explored using in situ Kelvin probe force microscopy. After the external voltage in the horizontal direction is applied, significant differences are demonstrated in the evolution of charge transport for epoxy matrix, filler/bubble, and their interface, respectively. The interface between Al2O3 and epoxy is easier to accumulate the negative charges and introduce shallow traps. Lots of positive charges are located around a bubble where deeper traps are present and could prevent charge migration. Thus, this work offers extended experimental support to understanding the mechanism of charge transport in dielectric composites.
研究领域:
材料科学
·
电气工程
✓ 已验证
DOI
高影响因子
Journal of the American Chemical Society
·
2016
·
IF 13.038
Chaodan Pu,Xiaogang Peng
Electronic traps at the inorganic–organic interface of colloidal quantum dots (QDs) are detrimental to their luminescent properties. Several types of interface traps were identified for single-crystalline CdSe/CdS core/shell QDs, which were all found to be extrinsic to either the core/shell structure or their optical performance. The electron traps—presumably excess or unpassivated Cd surface sites—are shallow ones and could be readily isolated from the electron wave function of the excitons with more than ∼2 monolayers of CdS shell. There were two identifiable deep hole traps within the bandgap of the QDs, i.e., the surface adsorbed H2S and unpassivated surface S sites. The surface adsorbed H2S could be removed by either degassing processes or photochemical decomposition of H2S without damaging the QDs. The unpassivated surface S sites could be removed by surface treatment with cadmium carboxylates. Understanding of the surface traps enabled establishment of new phosphine-free synthetic schemes for either single-precursor or successive-ion-layer-adsorption-and-reaction approach, which yielded CdSe/CdS core/shell QDs with near-unity photoluminescence quantum yield and monoexponential photoluminescence decay dynamics with 2–10 monolayers of CdS shell.
研究领域:
材料科学
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纳米技术
·
光电技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials
·
2020
·Vol. 13
·期 6
·1410
·
IF 3.057
Yi-Fei Zhu,Tong Jiang,Lei Li,Long-Xiang Cheng,Jun-Cheng Zhang
Trap-controlled mechanoluminescent (ML) materials characterized by reproducible mechanoluminescence (ML) after irradiation recharging have shown attractive prospects in applications including stress distribution visualization, stress-driven light sources, and anti-counterfeiting. However, these materials generally suffer from the difficulty of achieving non-decaying ML when subjected to continuous mechanical stimulation. Herein, we develop a trap-controlled reproducible ML material, Li2MgGeO4:Mn2+, and report its short-term non-decaying ML behavior. Investigation of trap properties suggests that the unique non-decaying ML behavior should arise from the deep traps existing in Li2MgGeO4:Mn2+, which provide electron replenishment for shallow traps that release small numbers of electrons during short-term cyclic friction. Our results are expected to provide a reference for the ultimate achievement of long-term non-decaying ML in such materials.Keywords:mechanoluminescence;traps;phosphors
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2025
·Vol. 131
·期 6
·1-7
·
IF 2.8
Yuan Lifang,Wang Junzhong,Huang Zhijin,Shen Kaixiang
Long afterglow phosphors have garnered significant attention for their ability to emit light long after excitation ceases. Afterglow emission relies on metastable trap levels within the bandgap of the host materials. Effective trap engineering strategies to optimize traps are critical in determining the afterglow performance. In this study, we investigate the codoping of Bi 3+ and Er 3+ into LiTaO 3 to enhance afterglow performance. Through high-temperature solid-state synthesis, a series of LiTaO 3 :x%Bi 3+ , y%Er 3+ (x = 0 or 0.5%, y = 0.1–4.0%) samples were prepared successfully. Structural characterization confirmed the successful incorporation of Bi 3+ and Er 3+ into the Li⁺ sites without disrupting the host lattice. Photoluminescence studies revealed that Bi³⁺ codoping significantly enhances the green emission of Er³⁺, with optimal performance achieved at 1.0% Er 3+ doping. Thermoluminescence (TL) analysis demonstrated the presence of traps with the depth of 0.748 eV, enabling prolonged afterglow emission at room temperature. The afterglow mechanism involves charge carrier storage in traps under UV excitation, followed by thermal release and recombination at luminescent centers, facilitated by energy transfer from Bi 3+ to Er 3+ . This work provides a strategy for designing a long afterglow phosphor through controlled codoping, offering insights into trap engineering and energy transfer processes in perovskite-based luminescent materials.
研究领域:
材料科学
·
光学材料
·
固体物理
·
发光学
✓ 已验证
产品关联
DOI
高影响因子
Nanomaterials
·
2023
·Vol. 13
·期 3
·406
·
IF 5.3
Beibei Jia,Jun Zhou,Jiaxin Chen,Zixuan Zhang,Yang Wang,Zepeng Lv,Kai Wu
Space charge accumulation greatly influences the dielectric performance of epoxy composites under high voltage. It has been reported that nano-fillers can suppress the charge accumulation in the bulk of insulation materials. However, it is still unclear how the nano-fillers influence the charge distribution at the interface between the filler and polymeric matrix. In this work, the dielectric properties and the local dynamic charge mobility behavior at the interface of barium titanate/epoxy resin (BTO/EP) composites were investigated from both bulk and local perspectives based on the macroscopic test techniques and in-situ Kelvin probe force microscopy (KPFM) methods. Charge injection and dissipation behavior exhibited significant discrepancies at different interfaces. The interface between BTO and epoxy is easy to accumulates a negative charge, and nanoscale BTO (n-BTO) particles introduces deeper traps than microscale BTO (m-BTO) to inhibit charge migration. Under the same bias condition, the carriers are more likely to accumulate near the n-BTO than the m-BTO particles. The charge dissipation rate at the interface region in m-BTO/EP is about one order of magnitude higher than that of n-BTO/EP. This work offers experimental support for understanding the mechanism of charge transport in dielectric composites.Keywords:interface;epoxy resin;charge transport;trap
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Optical Materials Express
·
2018
·Vol. 8
·期 6
·1425-1434
·
IF 2.566
Cong Pan,Jun-Cheng Zhang,Min Zhang,Xu Yan,Hong-Di Zhang,Yun-Ze Long,Xin-Yuan Sun,Hai-Tao Jiang
Isomorphic materials tend to exhibit differentiated performance due to the small differences between the constituent atoms and the crystal structures. Inspired by the isomorphic strategy, herein we developed a novel trap-controlled mechanoluminescent (TC-ML) material, Pr3+-activated Sr2Nb2O7, that shows mechanoluminescence (ML) under the mechanical actions of compression and friction. Compared to the isomorphic Ca2Nb2O7:Pr3+ which requires a long-time delay to achieve high-contrast ML due to the strong long-lasting afterglow, Sr2Nb2O7:Pr3+ enables the obtaining of high-contrast ML in a short-time delay because of the weak short-lasting afterglow, which greatly simplifies the imaging process to facilitate the further application of ML. The investigations of structural and optical characteristics between Sr2Nb2O7:Pr3+ and Ca2Nb2O7:Pr3+ reveal that the unique ML of Sr2Nb2O7:Pr3+ should result from its lower trap concentration and shallower trap depth relative to Ca2Nb2O7:Pr3+. Our results are expected to deepen our understanding on the behavioral diversity of isomorphic phosphors and thereby broaden the horizon of designing and regulating TC-ML materials.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2022
·Vol. 11
·期 1
·149-157
·
IF 14.511
Yingfei Hu,Jun Wang,Huiting Huang,Jianyong Feng,Wangxi Liu,Hangmin Guan,Lingyun Hao,Zhaosheng Li,Zhigang Zou
Passivating surface traps plays a crucial role in mitigating the efficiency loss of solar water-splitting electrodes. However, the associated surface-trap passivation approaches require the introduction of an overlayer, complicating the fabrication process and increasing the capital cost of photoelectrodes. Herein, using CuBi2O4 as a prototype, an in situ surface-trap passivation strategy is developed, which yields a beneficial 90 mV anodic shift in hydrogen-evolution onset. Detailed mechanism investigations prove that the intentionally added Mg2+ ions in the precursor gradually segregate as MgO and enrich at the grain boundaries/surface of the CuBi2O4 multicrystalline, porous film during annealing, via which surface traps stemming from dangling bonds are spontaneously passivated; measurements of photovoltage generation characteristics and carrier lifetime validate the favorable roles of the MgO passivator in CuBi2O4 photocathodes. A bias-free water-splitting device is assembled using MgO-passivated CuBi2O4 and Mo-doped BiVO4 as the photocathode and photoanode respectively in a tandem configuration, delivering a solar-to-hydrogen conversion efficiency of approximately 0.41%.
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Junwei Zhang,Hui Lin,Wenhui Lou,Ruijin Hong,Zhaoxia Han,Dawei Zhang
Photo-stimulated luminescence materials have shown significant potential in the field of information storage, but they still face critical challenges in the regulation of trap levels. Herein, Ba 0.75 Al 11 O 17.25 :Eu 2+ fluorescent ceramics with abundant deep traps (1.24 eV) were reported via selective Mn 2+ co-doping. This material exhibits a homogeneous and dense crystalline structure, and its narrow-band emission at 514 nm is attributed to the energy transfer of Eu-Mn. Thermoluminescence curves, X-ray photoelectron spectroscopy and electron paramagnetic resonance spectra confirm that the trap levels primarily arise from oxygen vacancies and Reidinger defects, and Mn 2+ doping suppresses the formation of shallow traps through charge compensation mechanism. Significantly, information writing and reading in the ceramic medium were achieve using 254 nm UV light and 980 nm NIR light or thermal stimulation. The excellent photo-stimulated luminescence properties and high read-write stability of Ba 0.75 Al 11 O 17.25 :Eu 2+ , Mn 2+ are expected to accelerate the development of the next generation of optical storage technology.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
Advanced Optical Materials
·
2024
·
IF 8
Yixuan Xu,Zihan Cheng,Henggang Wang,Jun Jiang,Zuxu Zhou,Linger Feng,Xiaomeng Wang,Hengwei Lin,Kai Jiang
Luminescent materials with time-resolved dynamic discoloring afterglow (TDDA) hold significant potential for applications in anti-counterfeiting and data encryption. However, the afterglows coming from organic systems are usually unidentifiable due to their shorter durations (less than 10 s). Achievement of long-lasting and visually discernible TDDA remains highly desirable but challenging. In this work, the TDDA duration is successfully extended from less than 10 s to minutes by engineering the luminescent centers of carbon dots (CDs) and introducing deep trap-states in a composite of CDs and carbon nitrides (CNs) (named Y-CDs@CN). It is confirmed that the regulation of luminescent centers in CDs containing both C═N and C═O bonds is responsible for the color changes during TDDA from yellow to green. Moreover, the generation of deep trap states is found to be significant for prolonging the afterglow duration to minutes level through converting room temperature phosphorescence into long persistent luminescence, thus making the entire dynamic discoloring process being easily recognized to naked eyes. Furthermore, the afterglow of Y-CDs@CN can also be excited by blue light and even using white light of a cell phone. To harness these characteristics, potential applications of Y-CDs@CN for portable anti-counterfeiting and multidimensional information encryption are primarily investigated.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED PHYSICS
·
2022
·Vol. 132
·期 3
·
IF 2.877
Guo Heng,Zhu Yizhi,Chen Jinping,Xie Xiaoyu,Jiang Qingsong,Xu Chunxiang,Cui Qiannan,Shi Zengliang
As an effective means to endow lead halide perovskite nanocrystals (NCs) with new properties, ion doping has been widely applied. Transition metal Mn-doped CsPbCl 3 is of particular interest, as the Mn doping introduces new emission bands, improves photoluminescence quantum yield (PLQY), and even enhances stability. However, it is still insufficient to catch insight of the energy transfer process and luminescence characteristics of these high defect tolerance NCs doped with Mn ion. Here, we systematically studied the energy transfer from exciton to Mn 2+ ions in Mn-doped CsPbCl 3 NCs by variable temperature steady-state fluorescence spectra and time-resolved spectra. The abnormal attenuation behavior of the exciton and Mn 2+ with the change of temperature was observed, from which we predict the existence of shallow traps near the conduction band and these shallow traps will affect the luminescence properties by influencing the energy transfer process. We show a simple physical model invoking only shallow trap states that uniquely describe the temperature-dependent energy transfer between the exciton and the Mn 2+ ion. The thermometric performance (30–290 K) was studied in terms of relative thermal sensitivity, in which the calculated relative sensitivity range is ∼0.12%–1% K −1 .
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
INORGANIC CHEMISTRY
·
2020
·
IF 4.825
Zhihao Zhou,Puxian Xiong,Huailu Liu,Mingying Peng
Long persistent phosphors (LPPs) with ultraviolet (UV) luminescence have great potential for application in the fields of biomedicine, environmental, and catalysis. However, it is currently limited by the design and development of remarkable UV LPPs with a suitable spectral region and an ultralong afterglow decay time. Herein, we develop a new type of Bi3+-activated LiScGeO4 LPP, which exhibits bright ultraviolet-A (UVA) persistent luminescence (PersL). Because of the existence of numerous stabilized effective traps, the as-synthesized phosphors can undergo an ultralong PersL decay time far longer than 12 h. The PersL properties, effective trap depths, distributions, and types, as well as the possible mechanism for the PersL behavior of LiScGeO4:Bi3+, are comprehensively surveyed utilizing PersL excitation spectra, PersL decay analyses, thermoluminescence experiments, and X-ray photoelectron spectroscopy. This work can cover the shortage of LPPs in the UV region and also can lay the foundation for the development of more excellent UV LPPs toward versatile novel applications.
研究领域:
材料科学
·
生物医学
·
环境科学
·
催化领域
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）