Dye Sensitization for Ultraviolet Upconversion Enhancement

Upconversion nanocrystals that converted near-infrared radiation into emission in the ultraviolet spectral region offer many exciting opportunities for drug release, photocatalysis, photodynamic therapy, and solid-state lasing. However, a key challenge is the development of lanthanide-doped nanocrystals with efficient ultraviolet emission, due to low conversion efficiency. Here, we develop a dye-sensitized, heterogeneous core–multishelled lanthanide nanoparticle for ultraviolet upconversion enhancement. We systematically study the main influencing factors on ultraviolet upconversion emission, including dye concentration, excitation wavelength, and dye-sensitizer distance. Interestingly, our experimental results demonstrate a largely promoted multiphoton upconversion. The underlying mechanism and detailed energy transfer pathway are illustrated. These findings offer insights into future developments of highly ultraviolet-emissive nanohybrids and provide more opportunities for applications in photo-catalysis, biomedicine, and environmental science.

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Nano-Crystallization of Ln-Fluoride Crystals in Glass-Ceramics via Inducing of Yb3+ for Efficient Near-Infrared Upconversion Luminescence of Tm3+

Nanomaterials ◽

10.3390/nano11041033 ◽

2021 ◽

Vol 11 (4) ◽

pp. 1033

Author(s):

Jianfeng Li ◽

Yi Long ◽

Qichao Zhao ◽

Shupei Zheng ◽

Zaijin Fang ◽

...

Keyword(s):

Crystal Structures ◽

Near Infrared ◽

Upconversion Luminescence ◽

Glass Ceramics ◽

Upconversion Emission ◽

Ceramic Composites ◽

Wide Range ◽

Transmission Window ◽

Optical Applications ◽

Upconversion Emissions

Transparent glass-ceramic composites embedded with Ln-fluoride nanocrystals are prepared in this work to enhance the upconversion luminescence of Tm3+. The crystalline phases, microstructures, and photoluminescence properties of samples are carefully investigated. KYb3F10 nanocrystals are proved to controllably precipitate in the glass-ceramics via the inducing of Yb3+ when the doping concentration varies from 0.5 to 1.5 mol%. Pure near-infrared upconversion emissions are observed and the emission intensities are enhanced in the glass-ceramics as compared to in the precursor glass due to the incorporation of Tm3+ into the KYb3F10 crystal structures via substitutions for Yb3+. Furthermore, KYb2F7 crystals are also nano-crystallized in the glass-ceramics when the Yb3+ concentration exceeds 2.0 mol%. The upconversion emission intensity of Tm3+ is further enhanced by seven times as Tm3+ enters the lattice sites of pure KYb2F7 nanocrystals. The designed glass ceramics provide efficient gain materials for optical applications in the biological transmission window. Moreover, the controllable nano-crystallization strategy induced by Yb3+ opens a new way for engineering a wide range of functional nanomaterials with effective incorporation of Ln3+ ions into fluoride crystal structures.

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Effect of Li+ ions on enhancement of near-infrared upconversion emission in Y2O3:Tm3+/Yb3+ nanocrystals

Journal of Applied Physics ◽

10.1063/1.4764028 ◽

2012 ◽

Vol 112 (9) ◽

pp. 094701 ◽

Cited By ~ 40

Author(s):

Dongyu Li ◽

Yuxiao Wang ◽

Xueru Zhang ◽

Hongxing Dong ◽

Lu Liu ◽

...

Keyword(s):

Near Infrared ◽

Upconversion Emission

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High-energy organic group-induced spectrally pure upconversion emission in novel zirconate-/hafnate-based nanocrystals

CrystEngComm ◽

10.1039/c5ce01195g ◽

2015 ◽

Vol 17 (37) ◽

pp. 7169-7174 ◽

Cited By ~ 5

Author(s):

Xianghong He ◽

Bing Yan

Keyword(s):

Pump Power ◽

Near Infrared ◽

Incident Light ◽

Upconversion Emission ◽

High Energy ◽

Single Band ◽

Organic Group ◽

Red Fluorescence

A series of novel fluoride-based nanophosphors (NPs) exhibiting spectrally pure upconversion (UC) red fluorescence upon near-infrared (980 nm) excitation. The single-band deep-red UC luminescence feature of K3MF7:Yb3+,Er3+ (M = Zr, Hf) NPs is independent of the doping levels of Yb3+–Er3+ and the pump power of incident light.

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Two-Photon–NIR-II Antimicrobial Graphene-Nanoagent for Ultraviolet–NIR Imaging and Photoinactivation

10.21203/rs.3.rs-519688/v1 ◽

2021 ◽

Author(s):

WEN-SHUO KUO ◽

Chia-Yuan Chang ◽

Ping-Ching Wu ◽

Jiu-Yao Wang

Keyword(s):

Photodynamic Therapy ◽

Quantum Yield ◽

Chemical Modification ◽

Near Infrared ◽

Photon Absorption ◽

Excitation Wavelength ◽

Strong Electron ◽

Two Photon ◽

Photon Excitation ◽

Two Photon Excitation

Abstract BackgroundNitrogen doping and amino-group functionalization, which result in strong electron donation, can be achieved through chemical modification. Large π-conjugated systems of graphene quantum dot (GQD)-based materials acting as electron donors can be chemically manipulated with low two-photon excitation energy in a short photoexcitation time for improving the charge transfer efficiency of sorted nitrogen-doped amino acid–functionalized GQDs (sorted amino-N-GQDs). ResultsIn this study, a self-developed femtosecond Ti-sapphire laser optical system (222.7 nJ pixel−1 with 100-170 scans, approximately 0.65-1.11 s of total effective exposure times; excitation wavelength: 960 nm in the near-infrared II region) was used for chemical modification. The sorted amino-N-GQDs exhibited enhanced two-photon absorption, post-two-photon excitation stability, two-photon excitation cross-section, and two-photon luminescence through the radiative pathway. The lifetime and quantum yield of the sorted amino-N-GQDs decreased and increased, respectively. Furthermore, the sorted amino-N-GQDs exhibited excitation-wavelength-independent photoluminescence in the near-infrared region and generated reactive oxygen species after two-photon excitation. An increase in the size of the sorted amino-N-GQDs boosted photochemical and electrochemical efficacy and resulted in high photoluminescence quantum yield and highly efficient two-photon photodynamic therapy. ConclusionThe sorted dots can be used in two-photon contrast probes for tracking and localizing analytes during two-photon imaging in a biological environment and for conducting two-photon photodynamic therapy for eliminating infectious microbes.

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Структура и свойства полученных методом магнетронного распыления тонких графитоподобных пленок

Физика и техника полупроводников ◽

10.21883/ftp.2018.07.46051.8782 ◽

2018 ◽

Vol 52 (7) ◽

pp. 775

Author(s):

А.Я. Виноградов ◽

С.А. Грудинкин ◽

Н.А. Беседина ◽

С.В. Коняхин ◽

М.К. Рабчинский ◽

...

Keyword(s):

Substrate Temperature ◽

Deposition Temperature ◽

Near Infrared ◽

Crystalline Silicon ◽

Structural Defects ◽

Electrical And Optical Properties ◽

Absorption Intensity ◽

Infrared Spectral ◽

Ultraviolet Spectral Region ◽

Substrate Temperatures

AbstractThe structural, electrical, and optical properties of thin graphite-like films produced by magnetron- assisted sputtering onto crystalline silicon and quartz at substrate temperatures in the range from 320 to 620°C are studied. From analysis of the Raman spectra, it is established that, as the substrate temperature is elevated, the crystallite size increases and the concentration of structural defects and the content of amorphous carbon in the phase composition of the films decrease. It is found that, as the substrate temperature is elevated, the maximum of the absorption intensity in the ultraviolet spectral region of the optical absorption spectra shifts to longer wavelengths and the absorption intensity in the visible and near-infrared spectral regions increases. As the deposition temperature is elevated, the conductivity of the films increases from 0.2 Ω^–1 cm^–1 at 320°C to 30 Ω^–1 cm^–1 at 620°C.

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Monoclinic oxygen-deficient tungsten oxide nanowires for dynamic and independent control of near-infrared and visible light transmittance

Materials Horizons ◽

10.1039/c7mh01128h ◽

2018 ◽

Vol 5 (2) ◽

pp. 291-297 ◽

Cited By ~ 29

Author(s):

Shengliang Zhang ◽

Sheng Cao ◽

Tianran Zhang ◽

Qiaofeng Yao ◽

Adrian Fisher ◽

...

Keyword(s):

Visible Light ◽

Tungsten Oxide ◽

Near Infrared ◽

Underlying Mechanism ◽

Single Component ◽

Light Transmittance ◽

Independent Control ◽

Oxide Nanowires ◽

Electrochromic Material

Independent control of near-infrared and visible light using a single-component electrochromic material and its underlying mechanism are demonstrated.

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Upconversion lanthanide nanomaterials: basics introduction, synthesis approaches, mechanism and application in photodetector and photovoltaic devices

Nanotechnology ◽

10.1088/1361-6528/ac37e3 ◽

2021 ◽

Author(s):

Baharak Mehrdel ◽

Ali Nikbakht ◽

Azlan Abdul Aziz ◽

Mahmood S. Jameel ◽

Mohammed Ali Dheyab ◽

...

Keyword(s):

Optical Properties ◽

Near Infrared ◽

Surface Passivation ◽

Upconversion Emission ◽

High Energy ◽

Photovoltaic Devices ◽

Plasmonic Enhancement ◽

Host Matrix ◽

Emission Enhancement ◽

Improved Performance

Abstract Upconversion (UC) of lanthanide-doped nanostructure has the unique ability to convert low energy infrared (IR) light to high energy photons, which has significant potential for energy conversion applications. This review concisely discusses the basic concepts and fundamental theories of lanthanide nanostructures, synthesis techniques, and enhancement methods of upconversion for photovoltaic and for near-infrared (NIR) photodetector application. In addition, a few examples of lanthanide-doped nanostructures with improved performance were discussed, with particular emphasis on upconversion emission enhancement using coupling plasmon. The use of UC materials has been shown to significantly improve the NIR light-harvesting properties of photovoltaic devices and photocatalytic materials. However, the inefficiency of UC emission also prompted the need for additional modification of the optical properties of UC material. This improvement entailed the proper selection of the host matrix and optimization of the sensitizer and activator concentrations, followed by subjecting the UC material to surface-passivation, plasmonic enhancement, or doping. As expected, improving the optical properties of UC materials can lead to enhanced efficiency of photodetectors and photovoltaic devices.

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Multiplexed Graphene Quantum Dots with Excitation-Wavelength-Independent Photoluminescence, as Two-Photon Probes, and in Ultraviolet–Near Infrared Bioimaging

ACS Nano ◽

10.1021/acsnano.0c03915 ◽

2020 ◽

Vol 14 (9) ◽

pp. 11502-11509

Author(s):

Wen-Shuo Kuo ◽

Xing-Can Shen ◽

Chia-Yuan Chang ◽

Hui-Fang Kao ◽

Sheng-Han Lin ◽

...

Keyword(s):

Quantum Dots ◽

Near Infrared ◽

Graphene Quantum Dots ◽

Excitation Wavelength ◽

Two Photon

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Enhanced UV Light Emission by Core-Shell Upconverting Particles Powering up TiO2 Photocatalysis in Near-Infrared Light

Catalysts ◽

10.3390/catal10020232 ◽

2020 ◽

Vol 10 (2) ◽

pp. 232

Author(s):

Agnieszka Jarosz-Duda ◽

Paulina O’Callaghan ◽

Joanna Kuncewicz ◽

Przemysław Łabuz ◽

Wojciech Macyk

Keyword(s):

Near Infrared ◽

Light Emission ◽

Uv Light ◽

Protective Layer ◽

Upconversion Emission ◽

High Photocatalytic Activity ◽

Infrared Light ◽

Core Shell ◽

The Core ◽

Surface Luminescence

The core-shell NaYb0.99F4:Tm0.01@NaYF4 upconverting particles (UCPs) with a high UV emission to apply in NIR-driven photocatalysis were synthesized. The influence of the Yb3+ doping concentration in NaYxF4:Yb0.99−xTm0.01 core particles, and the role of the NaYF4 shell on the upconversion emission intensity of the UCPs were studied. The absorption of NIR light by the obtained UCPs was maximized by increasing the Yb3+ concentration in the core, reaching the maximum for Y3+-free particles (NaYb0.99F4:Tm0.01). Additionally, covering the NaYb0.99F4:Tm0.01 core with a protective layer of NaYF4 minimized the surface luminescence quenching, which significantly improved the efficiency of upconversion emission. The high intensity of the UV light emitted by the NaYb0.99F4:Tm0.01@NaYF4 under NIR irradiation resulted in a high photocatalytic activity of TiO2 (P25) mixed with the synthesized material.

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