DALTON TRANSACTIONS
·
2021
·Vol. 50
·期 29
·10299-10309
·
IF 4.39
Hailin Che,Peipei Dang,Yi Wei,Ziyong Cheng,Jun Lin
All-inorganic cesium lead halide (CsPbX3, X = Cl, Br, and I) perovskite quantum dots (PQDs) have great potential application due to their unique optoelectronic properties. However, poor luminescence stability caused by some inevitable factors such as light, moisture and heat always restricts their practical application. In this work, the stability of CsPbX3 (X = Cl0.5Br0.5, Br, and Br0.5I0.5) PQDs is improved by encapsulating them in stable hollow mesoporous NaYF4:Yb,Tm nanoparticles (HMNPs). Compared to pristine PQDs, HMNP–PQD composites exhibit stable photoluminescence properties that can be maintained for more than 60 days under ambient atmospheric conditions. Thanks to the protection of HMNPs, the composites show much higher long-term stability in highly humid air and enhanced stability against UV light treatment compared to naked CsPbBr3 PQDs. Based on the proposed confinement effects of PQDs coordinated with the hollow mesoporous structure of NaYF4:Yb/Tm, the related structural model of NaYF4:Yb/Tm@PQD composites is discussed. Moreover, dual-mode luminescence can be observed in the NaYF4:Yb/Tm@PQD nanocomposites under 365 nm UV light and 980 nm laser excitation, indicating that the as-designed composites have great potential for dual-mode anti-counterfeiting application. This work provides a new idea for the stabilization and application of CsPbX3 PQDs.
研究领域:
材料科学
·
光学
·
纳米技术
✓ 已验证
DOI
高影响因子
OPTICAL MATERIALS
·
2022
·
IF 3.754
Zhuobao Hong,Weihao Ye,Junjian He,Jie Luo,Linliang Yu,Xiaotang Liu
A simple sol-gel method was used to synthesize a hybrid nanostructure which can achieve the switching of dual-modal luminescence of NaYF 4 :Yb 3+ ,Er 3+ @CuInS 2 /ZnS. With 980 nm excitation, the nanoparticles exhibit red emissions, and exhibit green-yellow to red emissions under 365 nm excitation. It is noticed that the CuInS 2 /ZnS acts as a sub-energy level to mediate energy transfer between the rare earth ions of the NaYF 4 and CuInS 2 /ZnS QDs. We found that the dual-modal luminescent properties of the synthesized hybrid nanomaterials can be potentially applied in the field of anti-counterfeiting.
研究领域:
材料科学
·
光学
·
纳米技术
✓ 已验证
DOI
高影响因子
NANOTECHNOLOGY
·
2020
·Vol. 31
·期 36
·365705
·
IF 3.551
Bang Dong,Yongjun Yuan,Mingye Ding,Wangfeng Bai,Shiting Wu,Zhenguo Ji
Fluorescent anti-counterfeiting technique is generally based on the development of luminescent materials, which generally exhibit single-mode emissions under single-wavelength excitation, thus resulting in a poor anti-fake effect. To improve the anti-forgery performance of fluorescent anti-counterfeiting approaches, dual-mode luminescent nanoparticles with the form of a β-NaGdF4:Yb/Ho/Ce@β-NaYF4:Tb/Eu core–shell structure have been skillfully designed and synthesized by a co-precipitation strategy. Through the cross-relaxation process between Ce3+ and Ho3+ ions in the inner core region, the up-conversion luminescence colors of the as-synthesized samples can be turned from green to yellow and finally to red when adjusting the dopant concentration of Ce3+ in the core. By selecting Ce3+ as the sensitizer for harvesting the energy of incident ultraviolet (UV) light and introducing Gd3+ as the ideal intermediate for subsequent energy migration, the down-converting emission colors of the as-obtained samples are also regulated from green to red via a Gd3+-assisted interface energy transfer processes (Ce3+ → Gd3+ → Tb3+, Ce3+ → Gd3+ → Tb3+ → Eu3+). Consequently, dual-mode luminescence with multi-color outputs can be achieved in the pre-designed core–shell nanostructure under the excitation of a 980 nm near-infrared laser and 254 nm UV light. The designed nanoarchitecture with bright dual-mode emissions and tunable colors greatly improves the ability of modern anti-counterfeiting, demonstrating its promising applications in anti-fake and optical multiplexing.
研究领域:
材料科学
·
光学
·
纳米技术
✓ 已验证
DOI
高影响因子
Advanced Optical Materials
·
2021
·Vol. 9
·期 21
·2100814
·
IF 9.926
Kaimin Du,Manli Zhang,Yao Li,Huwei Li,Kai Liu,Chengyu Li,Jing Feng,Hongjie Zhang
Advanced fluorescent anticounterfeiting technology has attracted widespread attention and encourages people to develop reliable luminescent materials with multiple colors and tunable luminescence. Here, novel nanocomposites composed of perovskite quantum dots (PeQDs) and upconversion nanoparticles (UCNPs) are successfully designed and served as efficient anticounterfeiting inks. NaYF 4 :Yb/Tm@NaYF 4 :Yb core–shell UCNPs are formed first and then ultrasmall CsPbX 3 (X = Cl, Br, and I or mixed halide systems Cl/Br and Br/I) PeQDs linked on the surface of UCNPs by seeded-growth strategy. UCNPs-CsPbX 3 nanocomposites can not only provide multicolor downconversion luminescence (DCL) under ultraviolet (UV) excitation, but also produce tunable upconversion luminescence (UCL) under 980 nm continuous-wave laser excitation. Finally, UCX 3 nanocomposites are mixed with prepolystyrene (PS) and the resulting UCX 3 /PS with excellent water stability and photostability can be employed as multicolor fluorescent ink for both writing and printing. These findings not only present a general method to fabricate novel nanocomposites combining both advantages of UCNPs and PeQDs, but also provide insight for the practical application in the field of anticounterfeiting.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Zhurong Mo,Shaoshan Su,Yanping Huo,Hongli Wen,Andrzej Suchocki,Deshmukh Abdul Hakeem
Fundamental understanding of the Stokes and anti-Stokes emissions in luminescence materials and their mechanism is very important for different technological applications. In this article, we report the dual mode, down/upconversion (DC/UC), luminescence in a LiAlSi 2 O 6 (β-spodumene) single host along with its mechanistic investigations. A series of emission tunable Li 1- x AlSi 2 O 6 : x Er 3+ (LAS: x Er 3+ ; 0 ≤ x ≤ 0.07) and Li 0.99- y AlSi 2 O 6 :0.01Er 3+ , y Yb 3+ (LAS:0.01Er 3+ ,yYb 3+ ; 0.001 ≤ y ≤ 0.007) phosphor powders were prepared by solid state reaction method at 1300 °C. The formation of single-phase phosphors is verified by XRD technique and other structural properties are investigated by FT-IR, UV-Vis-NIR spectra. The phosphors produced NIR DC emission at 1535 nm (under 380 and 980 nm excitation) and an intense red UC emission at 655 nm (under both 980 and 808 nm excitations). The dual mode emission intensity of the LAS:0.01Er 3+ is further improved by co-doping Yb 3+ ions via energy transfer from Yb 3+ to Er 3+ . The red UC emission intensity of LAS:0.01Er 3+ ,0.005Yb 3+ phosphor under 980 nm excitation is ~10 times stronger than the singly doped LAS:0.01Er 3+ phosphor. In addition, the phosphors can also be efficiently excited by 808 nm laser and hence can be used for biological application since 808 nm NIR irradiation exhibits higher light penetration depth without inducing overheating. The mechanism of energy transfer from Yb 3+ to Er 3+ by considering different emission pathways viz: ground state absorption (GSA), excited state absorption (ESA), energy transfer upconversion (ETU), back energy transfer (BET) and cross relaxation (CR) are discussed in detail. Based on the dual mode emissions, the LAS: x Er 3+ and LAS: x Er 3+ , y Yb 3+ ( x = 0.1 and 0.001 ≤ y ≤ 0.007) phosphors could be a potential candidate not only for the biological application as bio-probe but also as energy convertors for solid-state lighting, displays, and solar cell applications.
研究领域:
材料科学
·
光学
·
光子学
·
生物技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）