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Metal complexes and nanoparticles for energy upconversion
Welcome to this issue of Dalton Transactions featuring the themed issue “Metal complexes and nanoparticles for energy upconversion”.
Molecular-based upconversion in homo/heterogeneous liquids and in micro/nanostructured solid materials
A step-by-step investigation to move TTA-UC from homogeneous solutions to nanostructured solid materials for new technological perspectives.
Using lead chalcogenide nanocrystals as spin mixers: a perspective on near-infrared-to-visible upconversion
This perspective highlights recent advances in the field of PbS NC-sensitized near-infrared-to-visible upconversion based on triplet–triplet annihilation in rubrene.
Current progress in the controlled synthesis and biomedical applications of ultrasmall (<10 nm) NaREF4 nanoparticles
This review primarily introduces new progress in preparation strategies of ultrasmall (<10 nm) NaREF4 upconversion nanoparticles, and their use in imaging and drug delivery.
Near infrared harvesting dye-sensitized solar cells enabled by rare-earth upconversion materials
Dye-sensitized solar cells (DSSCs) have been deemed as promising alternatives to silicon solar cells for the conversion of clean sunlight energy into electricity.
Prospects for efficient solar energy upconversion using metalloporphyrins as dual absorber-upconverters
Can metalloporphyrins be used in a dual absorber-upconverter capacity to improve photovoltaic efficiency?
Upconversion in photodynamic therapy: plumbing the depths
Upconversion photodynamic therapy uses sequential multiphoton absorption by transition metal nanoparticles (NaYF4/Yb3+/Er3+) to allow FRET excitation of traditional visible light-absorbing photosensitizers by deeply penetrating near infrared light (810 nm or 980 nm).
Bringing upconversion down to the molecular scale
After bulk solids and nanoparticles, examples of upconversion are now emerging at the discrete molecular scale in solution.
Hybridizing semiconductor nanocrystals with metal–organic frameworks for visible and near-infrared photon upconversion
Solid upconverters consisting of semiconductor nanocrystals and metal–organic frameworks (MOFs) show NIR-to-visible TTA-UC with large anti-stokes shifts.
Yb3+-sensitized upconversion and downshifting luminescence in Nd3+ ions through energy migration
A core–shell–shell nanostructure composed of NaGdF4:Yb/Tm@NaGdF4:Nd@NaYF4 is developed to realize Yb3+-sensitized upconversion and downshifting luminescence in Nd3+ ions.
Exploiting coumarin-6 as ancillary ligands in 1,10-phenanthroline Ir(III) complexes: generating triplet photosensitisers with high upconversion capabilities
A series of new Ir(III) complexes incorporating 3-(2-benzothiazolyl)-7-(diethylamino)coumarin (coumarin 6) and ethynylpyrene (EP) functionalised 1,10-phenanthroline (phen) were developed.
Fabrication of single-chain nanoparticles through the dimerization of pendant anthracene groups via photochemical upconversion
Visible light is used to drive the intramolecular dimerization of anthracenes on a methacrylic polymer to form single-chain nanoparticles.
A temperature sensor based on the enhanced upconversion luminescence of Li+ doped NaLuF4:Yb3+,Tm3+/Er3+ nano/microcrystals
In this paper, fluorescent and optical temperature sensing bi-functional Li+-doping NaLuF4:Ln (Ln = Yb3+,Tm3+/Er3+) nanocrystals were synthesized via a simple hydrothermal method using oleic acid as a capping ligand.
Facile preparation of multifunctionalisable ‘stealth’ upconverting nanoparticles for biomedical applications
Hide and Seek. Alendronate-modified upconverting nanoparticles display high colloidal stability, protein corona resistance, bright upconversion luminescence (800 nm excitation), and contain multifunctionalisation sites.
Up-conversion monodispersed spheres of NaYF4:Yb3+/Er3+: green and red emission tailoring mediated by heating temperature, and greatly enhanced luminescence by Mn2+ doping
Mn2+ doping resulted in greatly enhanced luminescent intensity and red shift of emission color. Elevating the temperature induced color tunable emission.
Plasmon-enhanced triplet–triplet annihilation upconversion of post-modified polymeric acceptors
Plasmonic enhancement of TTA-UC is demonstrated on an easily adaptable polymer platform containing silver nanoparticles and various covalently attached chromophores.
Exploiting the benefit of S0 → T1 excitation in triplet–triplet annihilation upconversion to attain large anti-stokes shifts: tuning the triplet state lifetime of a tris(2,2′-bipyridine) osmium(II) complex
The triplet state lifetime of an Os(bpy)3 complex showing strong S0 → T1 absorption was prolonged 30-fold by attaching Bodipy chromophores.
Controllable synthesis of lanthanide Yb3+ and Er3+ co-doped AWO4 (A = Ca, Sr, Ba) micro-structured materials: phase, morphology and up-conversion luminescence enhancement
The combination of CDs can mainly maintain the morphologies of AWO4:Yb3+,Er3+ but prominently increase their up-conversion luminescence performance.
Paper
Stimuli-responsive protection of optically excited triplet ensembles against deactivation by molecular oxygen
The temperature-responsive protection of optically created organic triplet ensembles against deactivation by molecular oxygen was realized.
NIR/blue light emission optimization of NaY1−(x+y)YbxF4:Tmy upconversion nanoparticles via Yb3+/Tm3+ dopant balancing
A data driven approach provides better understanding of the role of dopant balancing in the upconversion process and presents an effective strategy to enhance the optical properties of upconversion nanoparticles.
About this collection
Energy upconversion is the process in which a high energy excited state is populated upon the absorption of two or more photons of lower energy. This themed issue gathers the most recent and significant advances in upconversion systems based on energy transfer between lanthanide ions or sensitised triplet–triplet annihilation and explores possible applications across a broad range of fields including photovoltaic devices, photocatalysis, sensing, bioimaging and photodynamic therapy.