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Hydrogen-Bonded Two-Component Ionic Crystals Showing Enhanced Long-Lived Room-Temperature Phosphorescence via TADF-Assisted F?rster Resonance Energy Transfer
摘要： Molecular room-temperature phosphorescent (RTP) materials with long-lived excited states have attracted widespread attention in the fields of optical imaging, displays, and sensors. However, accessing ultralong RTP systems remains challenging and examples are still limited to date. Herein, a thermally activated delayed fluorescence (TADF)-assisted energy transfer route for the enhancement of persistent luminescence with an RTP lifetime as high as 2 s, which is higher than that of most state-of-the-art RTP materials, is proposed. The energy transfer donor and acceptor species are based on the TADF and RTP molecules, which can be self-assembled into two-component ionic salts via hydrogen-bonding interactions. Both theoretical and experimental studies illustrate the occurrence of effective F?rster resonance energy transfer (FRET) between donor and acceptor molecules with an energy transfer efficiency as high as 76%. Moreover, the potential for application of the donor–acceptor cocrystallized materials toward information security and personal identification systems is demonstrated, benefitting from their varied afterglow lifetimes and easy recognition in the darkness. Therefore, the work described in this study not only provides a TADF-assisted FRET strategy toward the construction of ultralong RTP, but also yields hydrogen-bonding-assembled two-component molecular crystals for potential encryption and anti-counterfeiting applications.
关键词： thermally activated delayed fluorescence,energy transfer,cocrystallization,hydrogen bonding self-assembly,room-temperature phosphorescence
更新于2025-09-10 09:29:36
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Recent Advances in Conjugated TADF Polymer Featuring in Backbone-Donor/Pendant-Acceptor Structure: Material and Device Perspectives
摘要： Along with the persistent research interest in organic light-emitting diode (OLED) display and lighting technology, a new studying topic is now focused on developing thermally activated delayed fluorescence (TADF) polymer emitters, with the purpose to achieve high-performance cost-effective, solution-processed OLEDs (s-OLEDs) purely from fluorescent-type materials. However, research in this topic is in its infancy about the designing rules of polymer structures, photophysical mechanisms and the correlated devices. In this Personal Account, mainly from our personal experience we will shortly introduce the historical developments, status and perspectives about one representative kinds of TADF polymers, i. e. the conjugated TADF polymers featuring in backbone-donor/pendant-acceptor (BDPA) structure scaffold, which shows very promising electroluminescent (EL) performance even using simple s-OLED structure. Special attention is focused on illustrate the molecular designing & synthesis motivation, chemistry & device tactics towards solving the limiting factors about the quantum yields and aggregation-quenching tendency in solid states. Further challenges and strategies towards optimizing their overall EL performance, e. g. simultaneous achieving extremely high external quantum efficiency, power efficiency and low roll-off rate, are also discussed.
关键词： thermally activated delayed fluorescence,exciplex,solution-processed,polymer,organic light-emitting diodes
更新于2025-09-10 09:29:36
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SOI wafer fabricated with a diamond BOX layer using surface activated bonding at room temperature
摘要： We propose a fabrication process for a silicon on insulator (SOI) wafer with a diamond buried oxide (BOX) layer by combining nanodiamond-seeding deposition and a surface-activated bonding technique for high-frequency and power device applications. The diamond layer was deposited on a base wafer by the spin-coating of nanodiamonds and microwave-plasma-enhanced chemical vapor deposition. The thermal conductivity of this deposited diamond layer was three times that of a conventional SiO2 layer. A silicon wafer was then bonded to the diamond layer at room temperature in ultrahigh vacuum without forming any voids. Additionally, this SOI wafer was used to fabricate devices at 1000 °C. Therefore, we believe that this SOI wafer with a diamond BOX layer and its fabrication process are important for the realization of self-heating devices such as next-generation high-frequency and power devices.
关键词： SOI wafer,surface-activated bonding,high-frequency devices,power devices,diamond BOX layer
更新于2025-09-10 09:29:36
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Highly efficient thermally activated delayed fluorescence with slow reverse intersystem crossing
摘要： We report an efficient luminescent molecule exhibiting thermally activated delayed fluorescence with a long-delayed fluorescence lifetime of 0.8 ms. Although the reverse intersystem crossing rate constant is small at 2.1 × 103 s?1, the molecule shows a high photoluminescence quantum yield of 89±2%, indicating the suppression of nonradiative decay from the triplet state.
关键词： Long triplet lifetime,Thermally activated delayed fluorescence (TADF),Reverse intersystem crossing (RISC)
更新于2025-09-10 09:29:36
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Preparation of activated carbon nanotube foams loaded with Ag-doped TiO2 for highly efficient photocatalytic degradation under UV and visible light
摘要： Titanium oxide (TiO2) has been widely investigated as a photocatalytic material for degradation of organic pollutant in waste water. However, nanosized granular TiO2 nanoparticles are hard to be recycled and re-utilized in water and many cause secondary pollution of water. Hence, we constructed a foam-like photocatalyst, which was composed of carbonaceous support: activated carbon nanotube foams and Ag-doped TiO2 nanoparticles through a method of a template synthesis and carbonization strategy. The as-prepared photocatalyst evidenced to be hierarchical macroporous and mesoporous and exhibited remarkable photocatalytic performance toward the degradation of unsymmetrical dimethylhydrazine under UV and visible light. The structure characterization and photocatalytic performance investigation confirmed that the enhanced photoresponse was attributed to the high efficiency of charge separation and the surface plasmon resonance effect of metallic Ag. The adsorption synergetic effect of the hierarchical porous structure also played an important role in photodegradation. The as-prepared photocatalyst showed great potential in the treatment of waste water containing organic pollutant.
关键词： Ag-doped TiO2,Photocatalytic degradation,Activated carbon nanotube foams,Unsymmetrical dimethylhydrazine,UV and visible light
更新于2025-09-10 09:29:36
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Kinetic Modelling of Transient Photoluminescence from Thermally Activated Delayed Fluorescence
摘要： A simplified state model and associated rate equations are used to extract the reverse intersystem crossing and other key rate constants from transient photoluminescence measurements of two high performance thermally activated delayed fluorescence materials. The values of the reverse intersystem crossing rate constant are in close agreement with established methods, but do not require a priori assumption of exponential decay kinetics, nor any additional steady state measurements. The model is also applied to measurements at different temperatures and found to reproduce previously reported thermal activation energies for the thermally activated delayed fluorescence process. Transient absorption measurements provide independent confirmation that triplet decay channels (neglected here) have no adverse effect on the fitting.
关键词： Thermally Activated Delayed Fluorescence,Transient Photoluminescence,Reverse Intersystem Crossing,Kinetic Modelling
更新于2025-09-10 09:29:36
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Room-Temperature Bonding of Wafers with Smooth Au Thin Films in Ambient Air Using a Surface-Activated Bonding Method
摘要： Wafers with smooth Au thin ?lms (rms surface roughness: < 0.5 nm, thickness: < 50 nm) were successfully bonded in ambient air at room temperature after an Ar radio frequency plasma activation process. The room temperature bonded glass wafers without any heat treatment showed a su?ciently high die-shear strength of 47–70 MPa. Transmission electron microscopy observations showed that direct bonding on the atomic scale was achieved. This surface-activated bonding method is expected to be a useful technique for future heterogeneous photonic integration.
关键词： Au-Au bonding,surface-activated bonding,room-temperature bonding,heterogeneous integration
更新于2025-09-10 09:29:36
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DOX/ICG-carrying γ-PGA-g-PLGA-based polymeric nanoassemblies for acid-triggered rapid DOX release combined with NIR-activated photothermal effect
摘要： To boost the efficacy of chemo-photothermal cancer treatment by the intracellular rapid release of doxorubicin (DOX) combined with near-infrared (NIR)-triggered photothermal effect of indocyanine green (ICG), the poly(γ-glutamic acid)-g-poly(lactic-co-glycolic acid) (γ-PGA-g-PLGA)-based polymeric nanoassemblies (PNAs) with simultaneous incorporation of DOX and ICG were developed in this work by simple one-step nanoprecipitation. The obtained DOX/ICG-loaded PNAs were characterized by a compact γ-PGA/DOX complexes-encapsulated PLGA-rich core covered with the co-assembly of amphiphilic D-α-tocopheryl polyethylene glycol succinate (TPGS), 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino(polyethylene glycol)] (DSPE-PEG) and ICG molecules. The robust cargo-loaded PNAs not only promoted the photo-stability of ICG in PBS, but also reduced ICG leakage from PNAs. With the milieu pH being altered from 7.4 to 5.0, the massive disruption of ionic DOX/γ-GA complexes and PLGA degradation considerably accelerated DOX release from payload-containing PNAs. The results of in vitro cellular uptake revealed that the DOX/ICG-loaded PNAs appreciably enhanced the cellular uptake of payloads by HeLa cells. Notably, through the intracellular acid-triggered rapid DOX release combined with the ICG-based NIR-activated hyperthermia and singlet oxygen generation, the combination therapy of DOX/ICG-loaded PNAs can use lower dosage of drugs to effectively inhibit proliferation of HeLa cells compared to the chemo or photothermal treatment alone, thus showing the great potential to improve efficacy of cancer treatment.
关键词： polymeric nanoassemblies,pH-triggered DOX release,NIR-activated photothermal treatment,amphiphilic graft copolymers,intracellular drug delivery
更新于2025-09-09 09:28:46
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Deoxynivalenol Decontamination in Raw and Germinating Barley Treated by Plasma-Activated Water and Intense Pulsed Light
摘要： The contamination of barley kernel by Fusarium fungi constitutes a serious problem for malting-related industries. Deoxynivalenol (DON) is a secondary metabolite produced by Fusarium fungi. DON can affect dopaminergic receptors in the human brain; it may cause symptoms such as vomiting, diarrhea, headache, and fever. The aims of this study were to evaluate the DON destruction effect of the intense pulsed light (IPL) and plasma-activated water (PAW) treatments in raw and germinating barley and assess the feasibility for disinfection in the malt industry. Both non-thermal methods degraded DON concentration in germinating barley. IPL treatment significantly reduced (p < 0.05) the DON level of germinating barley samples by 35.5% after 180 pulses in 60 s, and the PAW treatment effectively degraded the DON level by 34.6% in germinating barley in the first 5 min. However, higher barley quality remained for PAW treatment (germination rate: 81–100%) than for the IPL treatment (germination rate: 41–60%). For the raw barley samples, although significant reduction (30.9%) was achieved after 180 pulses of IPL treatment, noticeable quality (germination rate: 20–40%) alteration was observed. Significantly less DON degradation was achieved by the PAW treatment on raw barley than the germinating barley for all times. Overall, these findings suggested that PAW and IPL might potentially be used to reduce DON levels in some malt-related industry applications, and PAW was recommended as a better method than IPL to maintain the barley quality.
关键词： Deoxynivalenol degradation,Non-thermal treatment,Barley kernel,Plasma-activated water,Intense pulsed light
更新于2025-09-09 09:28:46
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Heteroleptic Copper(I) Complexes Prepared from Phenanthroline and Bis-Phosphine Ligands: Rationalization of the Photophysical and Electrochemical Properties
摘要： The electronic and structural properties of ten heteroleptic [Cu(NN)(PP)]+ complexes have been investigated. NN indicates 1,10-phenanthroline (phen) or 4,7-diphenyl-1,10-phenanthroline (Bphen); each of these ligands is combined with five PP bis-phosphine chelators, i.e., bis(diphenylphosphino)methane (dppm), 1,2-bis(diphenylphosphino)ethane (dppe), 1,3-bis(diphenylphosphino)propane (dppp), 1,2-bis(diphenylphosphino)benzene (dppb), and bis[(2-diphenylphosphino)phenyl] ether (POP). All complexes are mononuclear, apart from those based on dppm, which are dinuclear. Experimental data—also taken from the literature and including electrochemical properties, X-ray crystal structures, UV?vis absorption spectra in CH2Cl2, luminescence spectra and lifetimes in solution, in PMMA, and as powders—have been rationalized with the support of density functional theory calculations. Temperature dependent studies (78?358 K) have been performed for selected complexes to assess thermally activated delayed fluorescence. The main findings are (i) dependence of the ground-state geometry on the crystallization conditions, with the same complex often yielding different crystal structures; (ii) simple model compounds with imposed C2v symmetry ([Cu(phen)(PX3)2]+; X = H or CH3) are capable of modeling structural parameters as a function of the P?Cu?P bite angle, which plays a key role in dictating the overall structure of [Cu(NN)(PP)]+ complexes; (iii) as the P?Cu?P angle increases, the energy of the metal-to-ligand charge transfer absorption bands linearly increases; (iv) the former correlation does not hold for emission spectra, which are red-shifted for the weaker luminophores; (v) the larger the number of intramolecular π-interactions within the complex in the ground state, the higher the luminescence quantum yield, underpinning a geometry locking effect that limits the structural flattening of the excited state. This work provides a general framework to rationalize the structure?property relationships of [Cu(NN)(PP)]+, a class of compounds of increasing relevance for electroluminescent devices, photoredox catalysis, and solar-to-fuels conversion, which so far have been investigated in an unsystematic fashion, eluding a comprehensive understanding.
关键词： electrochemical properties,bis-phosphine ligands,photophysical properties,phenanthroline,thermally activated delayed fluorescence,density functional theory,heteroleptic copper(I) complexes
更新于2025-09-09 09:28:46