scholarly journals On the decay time of upconversion luminescence

Nanoscale ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 4959-4969 ◽  
Author(s):  
Jan Bergstrand ◽  
Qingyun Liu ◽  
Bingru Huang ◽  
Xingyun Peng ◽  
Christian Würth ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Numerical Simulations ◽  
Rate Equation ◽  
Decay Time ◽  
Upconversion Luminescence ◽  
Luminescence Decay ◽  
Cross Relaxation ◽  
Relaxation Processes ◽  
Intermediate States

Numerical simulations based on rate-equation models were performed to investigate how the upconversion luminescence decay is affected by the lifetimes of intermediate states, energy transfer, and cross-relaxation processes.

scholarly journals Процессы передачи энергии в эвлитите Sr-=SUB=-3-=/SUB=-Y(PO-=SUB=-4-=/SUB=-)-=SUB=-3-=/SUB=-, по отдельности и одновременно легированном ионами Tb-=SUP=-3+-=/SUP=- и Tm-=SUP=-3+-=/SUP=-

2022 ◽  
Vol 130 (1) ◽  
pp. 99
Author(s):  
Xiaowu Hu ◽  
Fabio Piccinelli ◽  
Marco Bettinelli
Keyword(s):  
Energy Transfer ◽  
Optical Spectroscopy ◽  
Emission Spectra ◽  
Cross Relaxation ◽  
Transfer Efficiency ◽  
Relaxation Processes ◽  
Donor Concentration ◽  
Acceptor Concentration ◽  
Transfer Processes ◽  
Double Phosphate

In this work the optical spectroscopy and the energy transfer processes involving the Tb3+and Tm3+ ions, have been studied in eulytite double phosphate hosts of the type Sr3Y(PO4)3 doped with various amounts of the two Ln ions. It has been found that several energy transfer and cross-relaxation processes are active in this class of materials, upon excitation in the 5D4 level of Tb, and in the 1G4 one of Tm. In particular, a Tb→Tm transfer of excitation has been found to quench strongly the 5D4 level of Tb. This process occurs with a transfer efficiency increasing from 0.08 to 0.62, for a donor concentration of 2 mol%, and an acceptor concentration increasing from 2 to 15 mol%. The emission spectra are strongly affected by the presence of Tb⟷Tm energy transfer, and Tm→Tm cross relaxation processes.

scholarly journals Energy Transfer and Cross-Relaxation Induced Efficient 2.78 μm Emission in Er3+/Tm3+: PbF2 mid-Infrared Laser Crystal

Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1024
Author(s):  
Jiayu Liao ◽  
Qiudi Chen ◽  
Xiaochen Niu ◽  
Peixiong Zhang ◽  
Huiyu Tan ◽  
...  
Keyword(s):  
Energy Transfer ◽  
First Principles ◽  
Spectroscopic Properties ◽  
Transfer Mechanism ◽  
Cross Relaxation ◽  
Relaxation Processes ◽  
Energy Transfer Mechanism ◽  
First Principles Calculations ◽  
Laser Materials ◽  
Mid Infrared

An efficient enhancement of 2.78 μm emission from the transition of Er3+: 4I11/2 → 4I13/2 by Tm3+ introduction in the Er/Tm: PbF2 crystal was grown by the Bridgman technique for the first time. The spectroscopic properties, energy transfer mechanism, and first-principles calculations of as-grown crystals were investigated in detail. The co-doped Tm3+ ion can offer an appropriate sensitization and deactivation effect for Er3+ ion at the same time in PbF2 crystal under the pump of conventional 800 nm laser diodes (LDs). With the introduction of Tm3+ ion into the Er3+: PbF2 crystal, the Er/Tm: PbF2 crystal exhibited an enhancing 2.78 μm mid-infrared (MIR) emission. Furthermore, the cyclic energy transfer mechanism that contains several energy transfer processes and cross-relaxation processes was proposed, which would well achieve the population inversion between the Er3+: 4I11/2 and Er3+: 4I13/2 levels. First-principles calculations were performed to find that good performance originates from the uniform distribution of Er3+ and Tm3+ ions in PbF2 crystal. This work will provide an avenue to design MIR laser materials with good performance.

Origin of strong red emission in Er3+-based upconversion materials: role of intermediate states and cross relaxation

2019 ◽  
Vol 21 (43) ◽  
pp. 24026-24033 ◽  
Author(s):  
Chiho Lee ◽  
Heeyeon Park ◽  
Woong Kim ◽  
Sungnam Park
Keyword(s):  
Upconversion Luminescence ◽  
Photoluminescence Spectroscopy ◽  
Cross Relaxation ◽  
Time Resolved ◽  
Red Emission ◽  
Intermediate States ◽  
Time Resolved Photoluminescence

Comprehensive NIR-to-visible upconversion luminescence mechanism in Er3+-based materials is elucidated by wavelength-dependent, power-dependent, and time-resolved photoluminescence spectroscopy.

scholarly journals Origin of visible and near IR upconversion in Yb3+-Tm3+-Er3+ doped BaMgF4 phosphor through energy transfer and cross-relaxation processes

2020 ◽  
Vol 99 ◽  
pp. 109511
Author(s):  
Bhushan P. Kore ◽  
Ashwini Kumar ◽  
Robin E. Kroon ◽  
Jacobus J. Terblans ◽  
Hendrik C. Swart
Keyword(s):  
Energy Transfer ◽  
Cross Relaxation ◽  
Relaxation Processes ◽  
Near Ir

Homogeneous Luminescence Decay Time-Based Assay Using Energy Transfer from Nanospheres

2002 ◽  
Vol 74 (9) ◽  
pp. 2151-2156 ◽  
Author(s):  
Jens M. Kürner ◽  
Otto S. Wolfbeis ◽  
Ingo Klimant
Keyword(s):  
Energy Transfer ◽  
Decay Time ◽  
Luminescence Decay ◽  
Luminescence Decay Time

scholarly journals Mechanisms of Upconversion Luminescence of Er3+-Doped NaYF4 via 980 and 1530 nm Excitation

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2767
Author(s):  
Yu Liu ◽  
Ziwen Zhou ◽  
Shaojian Zhang ◽  
Enming Zhao ◽  
Jing Ren ◽  
...  
Keyword(s):  
Steady State ◽  
Numerical Simulations ◽  
Rate Equation ◽  
Upconversion Luminescence ◽  
Convincing Evidence ◽  
Equation Modeling ◽  
Time Resolved ◽  
Lanthanide Ion ◽  
Spectroscopic Observations ◽  
Simple Strategy

To date, the mechanisms of Er3+ upconversion luminescence via 980 and 1530 nm excitation have been extensively investigated; however, based on discussions, they either suffer from the lack of convincing evidence or require elaborated and time-consuming numerical simulations. In this work, the steady-state and time-resolved upconversion luminescence data of Er3+-doped NaYF4 were measured; we therefore investigated the upconversion mechanisms of Er3+ on the basis of the spectroscopic observations and the simplified rate equation modeling. This work provides a relatively simple strategy to reveal the UCL mechanisms of Er3+ upon excitation with various wavelengths, which may also be used in other lanthanide ion-doped systems.

scholarly journals Time-Resolved Analysis of a Highly Sensitive Förster Resonance Energy Transfer Immunoassay Using Terbium Complexes as Donors and Quantum Dots as Acceptors

2007 ◽  
Vol 2007 ◽  
pp. 1-6 ◽  
Author(s):  
Niko Hildebrandt ◽  
Loïc J. Charbonnière ◽  
Hans-Gerd Löhmannsröben
Keyword(s):  
Quantum Dots ◽  
Energy Transfer ◽  
Decay Time ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Luminescence Decay ◽  
Forster Resonance Energy Transfer ◽  
Förster Resonance Energy Transfer ◽  
Time Resolved ◽  
Förster Resonance

CdSe/ZnS core/shell quantum dots (QDs) are used as efficient Förster Resonance Energy Transfer (FRET) acceptors in a time-resolved immunoassays with Tb complexes as donors providing a long-lived luminescence decay. A detailed decay time analysis of the FRET process is presented. QD FRET sensitization is evidenced by a more than 1000-fold increase of the QD luminescence decay time reaching ca. 0.5 milliseconds, the same value to which the Tb donor decay time is quenched due to FRET to the QD acceptors. The FRET system has an extremely large Förster radius of approx. 100 Å and more than 70% FRET efficiency with a mean donor-acceptor distance of ca. 84 Å, confirming the applied biotin-streptavidin binding system. Time-resolved measurement allows for suppression of short-lived emission due to background fluorescence and directly excited QDs. By this means a detection limit of 18 attomol QDs within the immunoassay is accomplished, an improvement of more than two orders of magnitude compared to commercial systems.

scholarly journals Multiband emission from single β-NaYF4(Yb,Er) nanoparticles at high excitation power densities and comparison to ensemble studies

Nano Research ◽  
2021 ◽  
Author(s):  
Florian Frenzel ◽  
Christian Würth ◽  
Oleksii Dukhno ◽  
Frédéric Przybilla ◽  
Lisa M. Wiesholler ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Single Particle ◽  
Near Infrared ◽  
Upconversion Luminescence ◽  
Excited State Absorption ◽  
High Energy ◽  
Excitation Power ◽  
Relaxation Processes ◽  
Excitation Power Density ◽  
Radiative Relaxation

AbstractEnsemble and single particle studies of the excitation power density (P)-dependent upconversion luminescence (UCL) of core and core-shell β-NaYF4:Yb,Er upconversion nanoparticles (UCNPs) doped with 20% Yb3+ and 1% or 3% Er3+ performed over a P regime of 6 orders of magnitude reveal an increasing contribution of the emission from high energy Er3+ levels at P > 1 kW/cm2. This changes the overall emission color from initially green over yellow to white. While initially the green and with increasing P the red emission dominate in ensemble measurements at P < 1 kW/cm2, the increasing population of higher Er3+ energy levels by multiphotonic processes at higher P in single particle studies results in a multitude of emission bands in the ultraviolet/visible/near infrared (UV/vis/NIR) accompanied by a decreased contribution of the red luminescence. Based upon a thorough analysis of the P-dependence of UCL, the emission bands activated at high P were grouped and assigned to 2–3, 3–4, and 4 photonic processes involving energy transfer (ET), excited-state absorption (ESA), cross-relaxation (CR), back energy transfer (BET), and non-radiative relaxation processes (nRP). This underlines the P-tunability of UCNP brightness and color and highlights the potential of P-dependent measurements for mechanistic studies required to manifest the population pathways of the different Er3+ levels.

THE DYNAMICS PROPERTIES ON LUMINESCENCE OF CeF3 CRYSTALS

2002 ◽  
Vol 09 (01) ◽  
pp. 371-374 ◽  
Author(s):  
CHAOSHU SHI ◽  
GUOBIN ZHANG ◽  
YAGUANG WEI ◽  
ZHENGFU HAN ◽  
JUNYAN SHI ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Temperature Dependence ◽  
Decay Time ◽  
Emission Band ◽  
Emission Spectra ◽  
Luminescence Decay ◽  
Luminescence Decay Time ◽  
Excitation Spectra ◽  
Defect Centers

This paper presents temperature dependence of emission spectra (290 nm and 340 nm bands), excitation spectra (250–3000 Å), luminescence decay time as well as their excitation effect for CeF 3 crystals. The results indicate that energy transfer from Ce 3+ to defect centers in the CeF 3 crystals was very efficient as temperature increased. The 340 nm emission band may originate from some defects near Ce 3+, rather than Ce 3+ perturbed defects.

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