In order to clarify the effect of pt addition on the stress of NiSi film, in situ stress measurements were taken to evaluate the stress evolution during heating and cooling treatment of Ni1- x Ptx Si alloy films with ...In order to clarify the effect of pt addition on the stress of NiSi film, in situ stress measurements were taken to evaluate the stress evolution during heating and cooling treatment of Ni1- x Ptx Si alloy films with different Pt concentrations. The room temperature stress, which is mainly thermal stress, was measured to be 775MPa and 1.31GPa for pure NiSi and pure PtSi films grown on Si (100) substrates,respectively. For Ni1-x Ptx Si alloy film, the room temperature stress was observed to increase steadily with Pt concentration. From the temperature dependent stress evolution curves,the stress relaxation temperature was found to increase from 440℃ (for pure NiSi film) to 620℃ (for pure PtSi film) with increasing Pt concentration, thus influencing the residual stress at room temperature.展开更多
Lithium(Li)metal is an attractive anode material with high capacity(3860 mAh g^(−1))and low potential(−3.04 V vs.standard hydrogen electrode)that shows highly promising for applications requiring high energy density.H...Lithium(Li)metal is an attractive anode material with high capacity(3860 mAh g^(−1))and low potential(−3.04 V vs.standard hydrogen electrode)that shows highly promising for applications requiring high energy density.However,the low electrochemical potential of Li metal makes it extremely reactive and inevitably forming a native oxidized layer in the ambient environment and repeatedly being consumed when exposed to liquid electrolytes.It is therefore beneficial to replace the poorly controlled native passivation layer with a tailored artificial SEI to improve interface management between Li and electrolyte and enhance the stability of Li metal battery.Here,we use an integrated glovebox-atomic layer deposition(ALD)-X-ray photoelectron spectroscopy(XPS)setup to in-situ investigating the pristine Li surface and the surface composition after Ar,H_(2)O_(2),N_(2)and NH_(3)plasma treatment processes.We find that the pristine Li foil is naturally being covered with a native oxidized layer,which is mainly composed of LiOH,Li_(2)O and Li_(2)CO_(3).These investigated plasmas can efficiently remove the oxidized layer from the Li metal surface,in which metallic Li surface is obtained after Ar or H2 plasma treatments,where Ar plasma is more efficient.While O_(2)plasma treatment produces a Li_(2)O layer,and N_(2)or NH_(3)plasma treatment leads to a Li3N(including a certain amount of LiON)layer on the Li surface.When employing the representative metallic Li(by Ar plasma treatment),Li_(2)O layer coated Li(by O_(2)plasma treatment)and Li3N layer coated Li(by N_(2)plasma treatment)foils as electrodes in symmetric Li metal batteries,the Li3N coated Li electrode exhibits much higher stability than that of metallic and Li_(2)O layer coated Li foils.Improved electrochemical performance has also been achieved in LiMn_(2)O_(4)(LMO)||Li full cells using Li anode with Li3N protective coating layer.Our work reveals the detailed process of surface engineering of Li metal anodes with plasma treatments by in vacuo XPS,which may also be extended to other gas-treatment or plasma-treatment for stabilization of high energy density Li metal anodes and other metal-based anodes.展开更多
Mechanoluminescence(ML)is the phenomenon describing the emission of light during mechanical action on a solid,leading to applications such as pressure sensing,damage detection and visualization of stress distributions...Mechanoluminescence(ML)is the phenomenon describing the emission of light during mechanical action on a solid,leading to applications such as pressure sensing,damage detection and visualization of stress distributions.In most cases,this mechanical action releases energy that was previously stored in the crystal lattice of the phosphor by means of trapped charge carriers.A drawback is the need to record the ML emission during a pressure event.In this work,we provide a method for adding a memory function to these pressure-sensitive phosphors,allowing an optical readout of the location and intensity of a pressure event in excess of 72 h after the event.This is achieved in the BaSi_(2)O_(2)N_(2):Eu^(2+) phosphor,where a broad trap depth distribution essential for the process is present.By merging optically stimulated luminescence(OSL),thermoluminescence(TL)and ML measurements,the influence of light,heat and pressure on the trap depth distribution is carefully analysed.This analysis demonstrates that mechanical action can not only lead to direct light emission but also to a reshuffling of trap occupations.This memory effect not only is expected to lead to new pressure sensing applications but also offers an approach to study charge carrier transitions in energy storage phosphors.展开更多
Plants reorient their growth towards light to optimize photosynthetic light capture--a process known as phototropism. Phototropins are the photoreceptors essential for phototropic growth towards blue and ultraviolet-A...Plants reorient their growth towards light to optimize photosynthetic light capture--a process known as phototropism. Phototropins are the photoreceptors essential for phototropic growth towards blue and ultraviolet-A (UV- A) light. Here we detail a phototropic response towards UV-B in etiolated Arabidopsis seedlings. We report that early differential growth is mediated by phototropins but clear phototropic bending to UV-B is maintained in photl phot2 double mutants. We further show that this phototropin-independent phototropic response to UV-B requires the UVoB photoreceptor UVR8. Broad UV-B-mediated repression of auxin-responsive genes suggests that UVR8 regulates directional bending by affecting auxin signaling. Kinetic analysis shows that UVR8-dependent directional bending occurs later than the phototropin response. We conclude that plants may use the full short-wavelength spectrum of sunlight to efficiently reorient photosynthetic tissue with incoming light.展开更多
Quantum dots are ideally suited for color conversion in light emitting diodes owing to their spectral tunability,high conversion efficiency and narrow emission bands.These properties are particularly important for dis...Quantum dots are ideally suited for color conversion in light emitting diodes owing to their spectral tunability,high conversion efficiency and narrow emission bands.These properties are particularly important for display backlights;the highly saturated colors generated by quantum dots justify their higher production cost.Here,we demonstrate the benefits of a hybrid remote phosphor approach that combines a green-emitting europium-doped phosphor with red-emitting CdSe/CdS core/shell quantum dots.Different stacking geometries,including mixed and separate layers of both materials,are studied at the macroscopic and microscopic levels to identify the configuration that achieves maximum device efficiency while minimizing material usage.The influence of reabsorption,optical outcoupling and refractive index-matching between the layers is evaluated in detail with respect to device efficiency and cost.From the findings of this study,general guidelines are derived to optimize both the cost and efficiency of CdSe/CdS and other(potentially cadmium-free)quantum dot systems.When reabsorption of the green and/or red emission is significant compared to the absorption strength for the blue emission of the pumping light emitting diode,the hybrid remote phosphor approach becomes beneficial.展开更多
Luminescence thermometry is a reliable approach for remote thermal sensing,and extensive studies have been devoted to designing a luminescence thermometer with heightened thermal sensitivity.Herein,we report a promisi...Luminescence thermometry is a reliable approach for remote thermal sensing,and extensive studies have been devoted to designing a luminescence thermometer with heightened thermal sensitivity.Herein,we report a promising luminescence thermometric material,Ta^(5+)-substituted K_(0.5)Na_(0.5)NbO_(3):0.003Er^(3+)transparent ferroelectric ceramics.The temperature sensing sensitivity is significantly improved by adjusting the concentration of Ta^(5+)in the material.Specifically,utilizing the fluorescence intensity ratio from the 2H_(11/2) and 4S_(3/2) thermally coupled states of Er^(3+)as a detecting signal within the temperature range of 273–543 K,an optimal maximum absolute sensitivity of 0.0058 K–1 and relative sensitivity of 0.0158 K–1 are achieved for K_(0.5)Na_(0.5)NbO_(3):0.65Ta^(5+)/0.003Er^(3+).Simultaneously,as the concentration of Ta5+increase,a unique evolution of structural phase transitions is observed from orthorhombic to tetragonal and then to cubic.This is accompanied by an improvement in luminescence temperature sensing properties,and the best sensitivity is demonstrated in the cubic-phase region.Intriguingly,a huge change in infrared luminescence properties as a function of temperature is found around the structure transition temperature of the samples.These results indicate a promising potential for achieving highly sensitive thermometry or monitoring phase structure transitions through luminescence thermometry behavior in the K_(0.5)Na_(0.5)NbO_(3) host.展开更多
文摘In order to clarify the effect of pt addition on the stress of NiSi film, in situ stress measurements were taken to evaluate the stress evolution during heating and cooling treatment of Ni1- x Ptx Si alloy films with different Pt concentrations. The room temperature stress, which is mainly thermal stress, was measured to be 775MPa and 1.31GPa for pure NiSi and pure PtSi films grown on Si (100) substrates,respectively. For Ni1-x Ptx Si alloy film, the room temperature stress was observed to increase steadily with Pt concentration. From the temperature dependent stress evolution curves,the stress relaxation temperature was found to increase from 440℃ (for pure NiSi film) to 620℃ (for pure PtSi film) with increasing Pt concentration, thus influencing the residual stress at room temperature.
基金FWO-Vlaanderen(No.GO87418N and 1S68518N)BOF-GOA UGent(No.01G01019)Solvay SA for financial support。
文摘Lithium(Li)metal is an attractive anode material with high capacity(3860 mAh g^(−1))and low potential(−3.04 V vs.standard hydrogen electrode)that shows highly promising for applications requiring high energy density.However,the low electrochemical potential of Li metal makes it extremely reactive and inevitably forming a native oxidized layer in the ambient environment and repeatedly being consumed when exposed to liquid electrolytes.It is therefore beneficial to replace the poorly controlled native passivation layer with a tailored artificial SEI to improve interface management between Li and electrolyte and enhance the stability of Li metal battery.Here,we use an integrated glovebox-atomic layer deposition(ALD)-X-ray photoelectron spectroscopy(XPS)setup to in-situ investigating the pristine Li surface and the surface composition after Ar,H_(2)O_(2),N_(2)and NH_(3)plasma treatment processes.We find that the pristine Li foil is naturally being covered with a native oxidized layer,which is mainly composed of LiOH,Li_(2)O and Li_(2)CO_(3).These investigated plasmas can efficiently remove the oxidized layer from the Li metal surface,in which metallic Li surface is obtained after Ar or H2 plasma treatments,where Ar plasma is more efficient.While O_(2)plasma treatment produces a Li_(2)O layer,and N_(2)or NH_(3)plasma treatment leads to a Li3N(including a certain amount of LiON)layer on the Li surface.When employing the representative metallic Li(by Ar plasma treatment),Li_(2)O layer coated Li(by O_(2)plasma treatment)and Li3N layer coated Li(by N_(2)plasma treatment)foils as electrodes in symmetric Li metal batteries,the Li3N coated Li electrode exhibits much higher stability than that of metallic and Li_(2)O layer coated Li foils.Improved electrochemical performance has also been achieved in LiMn_(2)O_(4)(LMO)||Li full cells using Li anode with Li3N protective coating layer.Our work reveals the detailed process of surface engineering of Li metal anodes with plasma treatments by in vacuo XPS,which may also be extended to other gas-treatment or plasma-treatment for stabilization of high energy density Li metal anodes and other metal-based anodes.
基金support by the FWO-Vlaanderen(Fund for Scientific Research—Flanders)via grant(1S33317N).
文摘Mechanoluminescence(ML)is the phenomenon describing the emission of light during mechanical action on a solid,leading to applications such as pressure sensing,damage detection and visualization of stress distributions.In most cases,this mechanical action releases energy that was previously stored in the crystal lattice of the phosphor by means of trapped charge carriers.A drawback is the need to record the ML emission during a pressure event.In this work,we provide a method for adding a memory function to these pressure-sensitive phosphors,allowing an optical readout of the location and intensity of a pressure event in excess of 72 h after the event.This is achieved in the BaSi_(2)O_(2)N_(2):Eu^(2+) phosphor,where a broad trap depth distribution essential for the process is present.By merging optically stimulated luminescence(OSL),thermoluminescence(TL)and ML measurements,the influence of light,heat and pressure on the trap depth distribution is carefully analysed.This analysis demonstrates that mechanical action can not only lead to direct light emission but also to a reshuffling of trap occupations.This memory effect not only is expected to lead to new pressure sensing applications but also offers an approach to study charge carrier transitions in energy storage phosphors.
文摘Plants reorient their growth towards light to optimize photosynthetic light capture--a process known as phototropism. Phototropins are the photoreceptors essential for phototropic growth towards blue and ultraviolet-A (UV- A) light. Here we detail a phototropic response towards UV-B in etiolated Arabidopsis seedlings. We report that early differential growth is mediated by phototropins but clear phototropic bending to UV-B is maintained in photl phot2 double mutants. We further show that this phototropin-independent phototropic response to UV-B requires the UVoB photoreceptor UVR8. Broad UV-B-mediated repression of auxin-responsive genes suggests that UVR8 regulates directional bending by affecting auxin signaling. Kinetic analysis shows that UVR8-dependent directional bending occurs later than the phototropin response. We conclude that plants may use the full short-wavelength spectrum of sunlight to efficiently reorient photosynthetic tissue with incoming light.
基金the IWT-Vlaanderen(Agency for Innovation by Science and Technology in Flanders)for a scholarship(111597 and 121024)support by the European Commission via the Marie-Sklodowska Curie action Phonsi(H2020-MSCA-ITN-642656)+2 种基金the Belgian Science Policy office(IAP 7.35,photon-ics@be)Ghent University(GOA 01G01513)the IWT-Vlaanderen for the SBO-IWT grant LumiCoR(SBO130030).
文摘Quantum dots are ideally suited for color conversion in light emitting diodes owing to their spectral tunability,high conversion efficiency and narrow emission bands.These properties are particularly important for display backlights;the highly saturated colors generated by quantum dots justify their higher production cost.Here,we demonstrate the benefits of a hybrid remote phosphor approach that combines a green-emitting europium-doped phosphor with red-emitting CdSe/CdS core/shell quantum dots.Different stacking geometries,including mixed and separate layers of both materials,are studied at the macroscopic and microscopic levels to identify the configuration that achieves maximum device efficiency while minimizing material usage.The influence of reabsorption,optical outcoupling and refractive index-matching between the layers is evaluated in detail with respect to device efficiency and cost.From the findings of this study,general guidelines are derived to optimize both the cost and efficiency of CdSe/CdS and other(potentially cadmium-free)quantum dot systems.When reabsorption of the green and/or red emission is significant compared to the absorption strength for the blue emission of the pumping light emitting diode,the hybrid remote phosphor approach becomes beneficial.
基金This work was supported by the National Natural Science Foundation of China(Nos.11774052)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(SJCX22_0048).
文摘Luminescence thermometry is a reliable approach for remote thermal sensing,and extensive studies have been devoted to designing a luminescence thermometer with heightened thermal sensitivity.Herein,we report a promising luminescence thermometric material,Ta^(5+)-substituted K_(0.5)Na_(0.5)NbO_(3):0.003Er^(3+)transparent ferroelectric ceramics.The temperature sensing sensitivity is significantly improved by adjusting the concentration of Ta^(5+)in the material.Specifically,utilizing the fluorescence intensity ratio from the 2H_(11/2) and 4S_(3/2) thermally coupled states of Er^(3+)as a detecting signal within the temperature range of 273–543 K,an optimal maximum absolute sensitivity of 0.0058 K–1 and relative sensitivity of 0.0158 K–1 are achieved for K_(0.5)Na_(0.5)NbO_(3):0.65Ta^(5+)/0.003Er^(3+).Simultaneously,as the concentration of Ta5+increase,a unique evolution of structural phase transitions is observed from orthorhombic to tetragonal and then to cubic.This is accompanied by an improvement in luminescence temperature sensing properties,and the best sensitivity is demonstrated in the cubic-phase region.Intriguingly,a huge change in infrared luminescence properties as a function of temperature is found around the structure transition temperature of the samples.These results indicate a promising potential for achieving highly sensitive thermometry or monitoring phase structure transitions through luminescence thermometry behavior in the K_(0.5)Na_(0.5)NbO_(3) host.