Perovskite quantum dot light-emitting diodes(Pe-QLEDs)have shown immense application potential in display and lighting fields due to their narrow full-width at half maximum(FWHM)and high photoluminescence quantum yiel...Perovskite quantum dot light-emitting diodes(Pe-QLEDs)have shown immense application potential in display and lighting fields due to their narrow full-width at half maximum(FWHM)and high photoluminescence quantum yield(PLQY).Despite significant advancements in their performance,challenges such as defects and ion migration still hinder their long-term stability and operational efficiency.To address these issues,various optimization strategies,including ligand engineering,interface passivation,and self-assembly strategy,are being actively researched.This review focuses on the synthesis methods,challenges and optimization of perovskite quantum dots,which are critical for the commercialization and large-scale production of high-performance and stable Pe-QLEDs.展开更多
Photoluminescence(PL)is one of the most important properties of metal nanoclusters(NCs).Achieving effi⁃cient white light emission in metal NCs with a precise structures is important for practical applications but rema...Photoluminescence(PL)is one of the most important properties of metal nanoclusters(NCs).Achieving effi⁃cient white light emission in metal NCs with a precise structures is important for practical applications but remains a great challenge.Here,we report the efficient white emission from Au_(10) NCs by elaborately deploying the surface chemistry engi⁃neering strategy.Specifically,the bis-aldehyde ligands of 4-hydroxyisophthalaldehyde(HOA)are decorated on the surface of Au_(10)(SG)_(10) NCs(glutathione denoted as SG)through the cross-linking reaction of imine bonds(-CH==N-).The combination of 477 nm blue emission from HOA ligands and 620 nm orange-yellow emission from Au_(10)(SG)_(10) NCs generates white-light emission in HOA-Au_(10)(SG)_(10) NCs in the solvent mixture of ethanol and water.More importantly,dynamic color tuning from blue light to yellow light is achieved by controlling the volume fraction of ethanol in the solvent mixture.In addi⁃tion,the as-formed imine bonds significantly improve the structural rigidity of HOA-Au_(10)(SG)_(10) NCs,resulting in the 51.2%absolute photoluminescence quantum yield(PLQY)of white emission.The present study exemplifies the paradigm to control the emission color and improve the PLQY of metal NCs through rational surface chemistry engineering.展开更多
The charge carrier transport and recombination dynamics in the quantum dots-based light-emitting diodes(QLEDs)featuring multiple emitting layers(M-EMLs)has a great impact on the device performance.In this work,QLEDs b...The charge carrier transport and recombination dynamics in the quantum dots-based light-emitting diodes(QLEDs)featuring multiple emitting layers(M-EMLs)has a great impact on the device performance.In this work,QLEDs based on M-EMLs separated by polyethyleneimine ethoxylated(PEIE)layer with different stacking sequences of blue(B),green(G),and red(R)QDs layer were used to intuitively explore the injection,transportation and recombination processes of the charge carriers in QLEDs by using the time-resolved electroluminescence(TrEL)spectra.From the TrEL spectra mea-surements,green and red emissions were obtained first in the QLEDs with the EMLs sequences of G/PEIE/B/PEIE/R and B/PEIE/R/PEIE/G along the direction of light emission,respectively.While the QLEDs adopt EMLs sequences of B/PEIE/G/PEIE/R,the blue,green and red emissions were obtained nearly at the same time.The above phenomenon can be attributed to different charge carrier transmission and radiation recombination process in the EMLs due to different valence band offsets and conduction band offsets between R-,G-and B-QDs by using different sequences of EMLs.White emission with coordi-nates of(0.31,0.31)and correlated color temperature(CCT)of 5916 K was obtained in the QLEDs with the EMLs se-quences of B/PEIE/G/PEIE/R,which can be attributed to the relative uniform emission of B-,G-and R-QDs due to the effec-tive injection and radiation recombination of charge carriers in each of the EMLs.The above results have great significance for further understanding and improving the performance of QLEDs with M-EMLs.展开更多
Building a lunar human base is one of the important goals of human lunar exploration.This paper proposes a method for the production of oxygen by combining photothermal synergistic water decomposition with high-temper...Building a lunar human base is one of the important goals of human lunar exploration.This paper proposes a method for the production of oxygen by combining photothermal synergistic water decomposition with high-temperature carbon dioxide electrolysis,utilizing the full solar spectrum.The optimal oxygen production rates under different solid oxide electrolysis cell inlet temperatures T_(e),ultraviolet(UV)separation wavelengths λ_(2),infrared(IR)separation wavelengths,and photovoltaic cell materials were explored.The results indicate that the inlet temperature of the solid oxide electrolysis cell should be as high as possible so that more carbon dioxide can be converted into carbon monoxide and oxygen.Furthermore,when the ultraviolet separation wavelength is approximately 385 nm,the proportion of solar energy allocated to the photoreaction and electrolysis cell is optimal,and the oxygen production rate is highest at 2.754×10^(-4) mol/s.Moreover,the infrared separation wavelength should be increased as much as possible within the allowable range to increase the amount of solar radiation allocated to the electrolysis cell to improve the rate of oxygen generation.In addition,copper indium gallium selenide(CIGS)has a relatively large separation wavelength,which can result in a high oxygen production rate of 3.560×10^(-4) mol/s.The proposed integrated oxygen production method can provide a feasible solution for supplying oxygen to a lunar human base.展开更多
Display devices have significantly changed our daily life for decades,from the watches,television,to the laptop and smartphone.As the desire of advanced display device with high-resolution,long operation life and ligh...Display devices have significantly changed our daily life for decades,from the watches,television,to the laptop and smartphone.As the desire of advanced display device with high-resolution,long operation life and lightweight properties,several display techniques have been demonstrated.There are mainly four types of electronic display device:cathode ray tube(CRT),liquid-crystal display(LCD),organic light-emitting diode(OLED),and micro-LED.Due to the different working principles and device structures,each type of display device has its special characteristic properties.The performance of devices could be adjusted through the material selection or device design.With careful device structure regulation,not only the efficiency but also the stability would be improved.Herein,a brief review of innovative strategies towards the structure design is presented.展开更多
The effect of dolomite with different particle size fractions on hematite flotation was studied using sodium oleate as collector at p H of about 9. The effect mechanism of dolomite on hematite flotation was investigat...The effect of dolomite with different particle size fractions on hematite flotation was studied using sodium oleate as collector at p H of about 9. The effect mechanism of dolomite on hematite flotation was investigated by means of solution chemistry, ultraviolet spectrophotometry(UV), inductively coupled plasma atomic emission spectrometry(ICP-AES) and X-ray photoelectron spectroscopy(XPS). It is observed that dolomite with different size fractions has depressing effect on hematite flotation using sodium oleate as collector, and dolomite could be the "mineral depressant" of hematite using sodium oleate as collector. The reasons for that are concerned with sodium oleate consumption and the adsorption onto hematite of dissolved species of dolomite.展开更多
A rapid and sensitive fluorometric method for the enzymatic detection of ethanol using CdSe/ZnS quantum dots （QDs） is proposed. The photoluminescence of QDs is sensitive to H202. This finding leads to a novel approa...A rapid and sensitive fluorometric method for the enzymatic detection of ethanol using CdSe/ZnS quantum dots （QDs） is proposed. The photoluminescence of QDs is sensitive to H202. This finding leads to a novel approach for the determination of ethanol using alcohol oxidase （AOx） which, on oxidation of ethanol, produces H202. The method has higher sensitivity, wider analytical range （0.1-8 mmol/L）, and a lower detection limit （0.05 mmol/L）. The relationship between quenching of the photoluminescence of the QDs and the concentration of ethanol is linear.展开更多
Crafting charge transfer channels at titanium dioxide(TiO_(2))based photoanodes remain a pressing bottleneck in solar-to-chemical conversion technology.Despite the tremendous attempts,TiO_(2)as the promising photoanod...Crafting charge transfer channels at titanium dioxide(TiO_(2))based photoanodes remain a pressing bottleneck in solar-to-chemical conversion technology.Despite the tremendous attempts,TiO_(2)as the promising photoanode material still suffers from sluggish charge transport kinetics.Herein,we propose an assembly strategy that involves the axial coordination grafting metalloporphyrin-based photosensitizer molecules(MP)onto the surface-modified TiO_(2)nanorods(NRs)photoanode,forming the composite MP/TiO_(2)NRs photoelectrode.As expected,the resulted unique MPB/TiO_(2)NRs photoelectrode displays significantly improved photocurrent density as compared to TiO_(2)NRs alone and MPA/TiO_(2)NRs photoelectrode.Scanning photoelectrochemical microscopy(SPECM)and intensity modulated photocurrent spectroscopy(IMPS)were employed to systematically evaluate the continuous photoinduced electron transfer(PET)dynamics for MP/TiO_(2)NRs photoelectrode.According to the data fitting,it is found that the photoelectron transfer rate(keff)constant for the MPB/TiO_(2)NRs is about 2.6 times higher than that for the pure TiO_(2)NRs under light irradiation.The high kinetic constant for the MPB/TiO_(2)NRs was ascribed to that the conjugated molecules MPB of D-A structure can effectively accelerate intramolecular electrons transfer as well as promote electrons taking part in the reduction reaction of I3to Iin the novel charge transfer channel.The results demonstrated in this study are expected to shed some light on investigating the mechanism in the charge transfer process of artificial photosynthesis and constructing efficient photoelectrodes.展开更多
Two-dimensional(2D)transition metal dichalcogenides(TMDs)and their heterostructures(HSs)exhibit unique optical properties and show great promise for developing next-generation optoelectronics.However,the photo-lumines...Two-dimensional(2D)transition metal dichalcogenides(TMDs)and their heterostructures(HSs)exhibit unique optical properties and show great promise for developing next-generation optoelectronics.However,the photo-luminescence(PL)quantum yield of monolayer(1L)TMDs is still quite low at room temperature,which severely lim-its their practical applications.Here we report a PL enhancement effect of 1L WS_(2) at room temperature when con-structing it into 1L-WS_(2)/hBN/1L-MoS_(2) vertical HSs.The PL enhancement factors(EFs)can be up to 4.2.By using transient absorption(TA)spectroscopy,we demonstrate that the PL enhancement effect is due to energy transfer from 1L MoS_(2) to 1L WS_(2).The energy transfer process occurs on a picosecond timescale and lasts more than one hundred picoseconds which indicates a prominent contribution from exciton-exciton annihilation.Furthermore,the PL en-hancement effect of 1L WS_(2) can be observed in 2L-MoS_(2)/hBN/1L-WS_(2) and 3L-MoS_(2)/hBN/1L-WS_(2) HSs.Our study provides a comprehensive understanding of the energy transfer process in the PL enhancement of 2D TMDs and a fea-sible way to optimize the performance of TMD-based optoelectronic devices.展开更多
The dissolution behavior of CaO-MgO-SiO2 glass fiber was investigated by scanning electron microscopy （SEM）, Fourier-transform infrared spectrometer （FTIR） and inductively coupled plasma atomic emission spectrosco...The dissolution behavior of CaO-MgO-SiO2 glass fiber was investigated by scanning electron microscopy （SEM）, Fourier-transform infrared spectrometer （FTIR） and inductively coupled plasma atomic emission spectroscopy （ICP-AES） using in-vitro tests. The results show that the soaked fiber is surrounded by an outer calcium-magnesium silicate hydrated layer, and there exists a balancing fimction between the formation and abscission of the hydrated layer during the dissolution process. The concentrations of leached ions increase constantly, and the mass loss of the fibers and pH changes of the solution are found to rise rapidly during the initial dissolution process, then their increasing rates are controlled by the balancing function of the hydrated layer at the subsequent dissolution stages. The dissolution rate constant and time for complete dissolution are estimated to be 274 ng/（cm2.h） and 15.2 d, respectively, presenting preferable biosolubilities.展开更多
文摘Perovskite quantum dot light-emitting diodes(Pe-QLEDs)have shown immense application potential in display and lighting fields due to their narrow full-width at half maximum(FWHM)and high photoluminescence quantum yield(PLQY).Despite significant advancements in their performance,challenges such as defects and ion migration still hinder their long-term stability and operational efficiency.To address these issues,various optimization strategies,including ligand engineering,interface passivation,and self-assembly strategy,are being actively researched.This review focuses on the synthesis methods,challenges and optimization of perovskite quantum dots,which are critical for the commercialization and large-scale production of high-performance and stable Pe-QLEDs.
文摘Photoluminescence(PL)is one of the most important properties of metal nanoclusters(NCs).Achieving effi⁃cient white light emission in metal NCs with a precise structures is important for practical applications but remains a great challenge.Here,we report the efficient white emission from Au_(10) NCs by elaborately deploying the surface chemistry engi⁃neering strategy.Specifically,the bis-aldehyde ligands of 4-hydroxyisophthalaldehyde(HOA)are decorated on the surface of Au_(10)(SG)_(10) NCs(glutathione denoted as SG)through the cross-linking reaction of imine bonds(-CH==N-).The combination of 477 nm blue emission from HOA ligands and 620 nm orange-yellow emission from Au_(10)(SG)_(10) NCs generates white-light emission in HOA-Au_(10)(SG)_(10) NCs in the solvent mixture of ethanol and water.More importantly,dynamic color tuning from blue light to yellow light is achieved by controlling the volume fraction of ethanol in the solvent mixture.In addi⁃tion,the as-formed imine bonds significantly improve the structural rigidity of HOA-Au_(10)(SG)_(10) NCs,resulting in the 51.2%absolute photoluminescence quantum yield(PLQY)of white emission.The present study exemplifies the paradigm to control the emission color and improve the PLQY of metal NCs through rational surface chemistry engineering.
文摘The charge carrier transport and recombination dynamics in the quantum dots-based light-emitting diodes(QLEDs)featuring multiple emitting layers(M-EMLs)has a great impact on the device performance.In this work,QLEDs based on M-EMLs separated by polyethyleneimine ethoxylated(PEIE)layer with different stacking sequences of blue(B),green(G),and red(R)QDs layer were used to intuitively explore the injection,transportation and recombination processes of the charge carriers in QLEDs by using the time-resolved electroluminescence(TrEL)spectra.From the TrEL spectra mea-surements,green and red emissions were obtained first in the QLEDs with the EMLs sequences of G/PEIE/B/PEIE/R and B/PEIE/R/PEIE/G along the direction of light emission,respectively.While the QLEDs adopt EMLs sequences of B/PEIE/G/PEIE/R,the blue,green and red emissions were obtained nearly at the same time.The above phenomenon can be attributed to different charge carrier transmission and radiation recombination process in the EMLs due to different valence band offsets and conduction band offsets between R-,G-and B-QDs by using different sequences of EMLs.White emission with coordi-nates of(0.31,0.31)and correlated color temperature(CCT)of 5916 K was obtained in the QLEDs with the EMLs se-quences of B/PEIE/G/PEIE/R,which can be attributed to the relative uniform emission of B-,G-and R-QDs due to the effec-tive injection and radiation recombination of charge carriers in each of the EMLs.The above results have great significance for further understanding and improving the performance of QLEDs with M-EMLs.
基金supported by the National Natural Science Foundation of China(52106276 and 52130601).
文摘Building a lunar human base is one of the important goals of human lunar exploration.This paper proposes a method for the production of oxygen by combining photothermal synergistic water decomposition with high-temperature carbon dioxide electrolysis,utilizing the full solar spectrum.The optimal oxygen production rates under different solid oxide electrolysis cell inlet temperatures T_(e),ultraviolet(UV)separation wavelengths λ_(2),infrared(IR)separation wavelengths,and photovoltaic cell materials were explored.The results indicate that the inlet temperature of the solid oxide electrolysis cell should be as high as possible so that more carbon dioxide can be converted into carbon monoxide and oxygen.Furthermore,when the ultraviolet separation wavelength is approximately 385 nm,the proportion of solar energy allocated to the photoreaction and electrolysis cell is optimal,and the oxygen production rate is highest at 2.754×10^(-4) mol/s.Moreover,the infrared separation wavelength should be increased as much as possible within the allowable range to increase the amount of solar radiation allocated to the electrolysis cell to improve the rate of oxygen generation.In addition,copper indium gallium selenide(CIGS)has a relatively large separation wavelength,which can result in a high oxygen production rate of 3.560×10^(-4) mol/s.The proposed integrated oxygen production method can provide a feasible solution for supplying oxygen to a lunar human base.
基金Projects(71572028,71872027)supported by the National Natural Science Foundation of China。
文摘Display devices have significantly changed our daily life for decades,from the watches,television,to the laptop and smartphone.As the desire of advanced display device with high-resolution,long operation life and lightweight properties,several display techniques have been demonstrated.There are mainly four types of electronic display device:cathode ray tube(CRT),liquid-crystal display(LCD),organic light-emitting diode(OLED),and micro-LED.Due to the different working principles and device structures,each type of display device has its special characteristic properties.The performance of devices could be adjusted through the material selection or device design.With careful device structure regulation,not only the efficiency but also the stability would be improved.Herein,a brief review of innovative strategies towards the structure design is presented.
基金Project(51374079)supported by the National Natural Science Foundation of ChinaProject(KKSY201521031)supported by Talent Cultivation Foundation of Kunming University of Science and Technology,ChinaProject(2015Y067)supported by Foundation of Yunnan Educational Committee,China
文摘The effect of dolomite with different particle size fractions on hematite flotation was studied using sodium oleate as collector at p H of about 9. The effect mechanism of dolomite on hematite flotation was investigated by means of solution chemistry, ultraviolet spectrophotometry(UV), inductively coupled plasma atomic emission spectrometry(ICP-AES) and X-ray photoelectron spectroscopy(XPS). It is observed that dolomite with different size fractions has depressing effect on hematite flotation using sodium oleate as collector, and dolomite could be the "mineral depressant" of hematite using sodium oleate as collector. The reasons for that are concerned with sodium oleate consumption and the adsorption onto hematite of dissolved species of dolomite.
基金Project(21005067)supported by the National Natural Science Foundation of ChinaProject(11JJ4015)supported by Natural Science Foundation of Hunan Province,China
文摘A rapid and sensitive fluorometric method for the enzymatic detection of ethanol using CdSe/ZnS quantum dots （QDs） is proposed. The photoluminescence of QDs is sensitive to H202. This finding leads to a novel approach for the determination of ethanol using alcohol oxidase （AOx） which, on oxidation of ethanol, produces H202. The method has higher sensitivity, wider analytical range （0.1-8 mmol/L）, and a lower detection limit （0.05 mmol/L）. The relationship between quenching of the photoluminescence of the QDs and the concentration of ethanol is linear.
基金We are thankful to the National Natural Science Foundation of China(22174110 and 22127803)the Industrial Support Plan of Gansu Provincial Department of Education(2021cyzc-01)the Special Fund Project for Guiding Local Scientific and Technological Development by the Central Government(2020-2060503-17).
文摘Crafting charge transfer channels at titanium dioxide(TiO_(2))based photoanodes remain a pressing bottleneck in solar-to-chemical conversion technology.Despite the tremendous attempts,TiO_(2)as the promising photoanode material still suffers from sluggish charge transport kinetics.Herein,we propose an assembly strategy that involves the axial coordination grafting metalloporphyrin-based photosensitizer molecules(MP)onto the surface-modified TiO_(2)nanorods(NRs)photoanode,forming the composite MP/TiO_(2)NRs photoelectrode.As expected,the resulted unique MPB/TiO_(2)NRs photoelectrode displays significantly improved photocurrent density as compared to TiO_(2)NRs alone and MPA/TiO_(2)NRs photoelectrode.Scanning photoelectrochemical microscopy(SPECM)and intensity modulated photocurrent spectroscopy(IMPS)were employed to systematically evaluate the continuous photoinduced electron transfer(PET)dynamics for MP/TiO_(2)NRs photoelectrode.According to the data fitting,it is found that the photoelectron transfer rate(keff)constant for the MPB/TiO_(2)NRs is about 2.6 times higher than that for the pure TiO_(2)NRs under light irradiation.The high kinetic constant for the MPB/TiO_(2)NRs was ascribed to that the conjugated molecules MPB of D-A structure can effectively accelerate intramolecular electrons transfer as well as promote electrons taking part in the reduction reaction of I3to Iin the novel charge transfer channel.The results demonstrated in this study are expected to shed some light on investigating the mechanism in the charge transfer process of artificial photosynthesis and constructing efficient photoelectrodes.
文摘Two-dimensional(2D)transition metal dichalcogenides(TMDs)and their heterostructures(HSs)exhibit unique optical properties and show great promise for developing next-generation optoelectronics.However,the photo-luminescence(PL)quantum yield of monolayer(1L)TMDs is still quite low at room temperature,which severely lim-its their practical applications.Here we report a PL enhancement effect of 1L WS_(2) at room temperature when con-structing it into 1L-WS_(2)/hBN/1L-MoS_(2) vertical HSs.The PL enhancement factors(EFs)can be up to 4.2.By using transient absorption(TA)spectroscopy,we demonstrate that the PL enhancement effect is due to energy transfer from 1L MoS_(2) to 1L WS_(2).The energy transfer process occurs on a picosecond timescale and lasts more than one hundred picoseconds which indicates a prominent contribution from exciton-exciton annihilation.Furthermore,the PL en-hancement effect of 1L WS_(2) can be observed in 2L-MoS_(2)/hBN/1L-WS_(2) and 3L-MoS_(2)/hBN/1L-WS_(2) HSs.Our study provides a comprehensive understanding of the energy transfer process in the PL enhancement of 2D TMDs and a fea-sible way to optimize the performance of TMD-based optoelectronic devices.
基金Projects(50872098, 51004080) supported by the National Natural Science Foundation of ChinaProject(B0903) supported by the Opening Fund of Research Center of Green Manufacturing and Energy-saving & Emission Reduction Technology of Wuhan University of Science and Technology, China
文摘The dissolution behavior of CaO-MgO-SiO2 glass fiber was investigated by scanning electron microscopy （SEM）, Fourier-transform infrared spectrometer （FTIR） and inductively coupled plasma atomic emission spectroscopy （ICP-AES） using in-vitro tests. The results show that the soaked fiber is surrounded by an outer calcium-magnesium silicate hydrated layer, and there exists a balancing fimction between the formation and abscission of the hydrated layer during the dissolution process. The concentrations of leached ions increase constantly, and the mass loss of the fibers and pH changes of the solution are found to rise rapidly during the initial dissolution process, then their increasing rates are controlled by the balancing function of the hydrated layer at the subsequent dissolution stages. The dissolution rate constant and time for complete dissolution are estimated to be 274 ng/（cm2.h） and 15.2 d, respectively, presenting preferable biosolubilities.
