The effects of long-term moisture changes on the migration,release,and bioavailability of selenium in soil are complex.Due to the lack of effective monitoring methods for precise quantification,its dynamic behavior is...The effects of long-term moisture changes on the migration,release,and bioavailability of selenium in soil are complex.Due to the lack of effective monitoring methods for precise quantification,its dynamic behavior is still unclear.Based on the DGT(Diffusive Gradients in Thin-films)technology,this study sets up three moisture control scenarios:continuous wet,wet-dry alternating,and continuous dry,and carries out a 6-month soil moisture control experiment.In the experiment,the DGT device collected the diffusion gradient data of soil selenium under different scenarios,and analyzed the migration characteristics of selenium in combination with the adsorption isotherm.Meanwhile,the release rate,migration coefficient,and bioavailability parameters of selenium are calculated by fitting the first-order kinetic model,further verifying the reliability and applicability of the DGT data.The experimental results demonstrate that under continuous wet conditions,the release rate of soil selenium reaches 1.85µg·cm^(-2)·h^(-1),with a migration coefficient of 0.012 cm^(2)·h^(-1)and a bioavailability parameter of 0.74;under wet-dry alternating conditions,they are 1.42µg·cm^(-2)·h^(-1),0.01 cm^(2)·h^(-1),and 0.68,respectively;under continuous dry conditions,the release rate of soil selenium is the smallest,at 0.88µg·cm^(-2)·h^(-1),with a migration coefficient of 0.004 cm^(-2)·h^(-1)and a bioavailability parameter of 0.5.The results of this experiment reveal the dynamic behavior of soil selenium under different moisture conditions and reflect the high efficiency of DGT technology in dynamic monitoring and quantitative analysis of soil selenium behavior,providing a scientific basis for the optimal management of rhizosphere soil selenium.展开更多
We report the performances of a chalcopyrite Cu(In, Ga)Se<sub>2 </sub>CIGS-based thin-film solar cell with a newly employed high conductive n-Si layer. The data analysis was performed with the help of the ...We report the performances of a chalcopyrite Cu(In, Ga)Se<sub>2 </sub>CIGS-based thin-film solar cell with a newly employed high conductive n-Si layer. The data analysis was performed with the help of the 1D-Solar Cell Capacitance Simulator (1D-SCAPS) software program. The new device structure is based on the CIGS layer as the absorber layer, n-Si as the high conductive layer, i-In<sub>2</sub>S<sub>3</sub>, and i-ZnO as the buffer and window layers, respectively. The optimum CIGS bandgap was determined first and used to simulate and analyze the cell performance throughout the experiment. This analysis revealed that the absorber layer’s optimum bandgap value has to be 1.4 eV to achieve maximum efficiency of 22.57%. Subsequently, output solar cell parameters were analyzed as a function of CIGS layer thickness, defect density, and the operating temperature with an optimized n-Si layer. The newly modeled device has a p-CIGS/n-Si/In<sub>2</sub>S<sub>3</sub>/Al-ZnO structure. The main objective was to improve the overall cell performance while optimizing the thickness of absorber layers, defect density, bandgap, and operating temperature with the newly employed optimized n-Si layer. The increase of absorber layer thickness from 0.2 - 2 µm showed an upward trend in the cell’s performance, while the increase of defect density and operating temperature showed a downward trend in solar cell performance. This study illustrates that the proposed cell structure shows higher cell performances and can be fabricated on the lab-scale and industrial levels.展开更多
An enhancement of mid-wavelength infrared absorbance is achieved via a cost-effectively chemical method to bend the flakes by grafting two types of alkane octane(C_(8)H_(18))and dodecane(C_(12)H_(26))onto the surface ...An enhancement of mid-wavelength infrared absorbance is achieved via a cost-effectively chemical method to bend the flakes by grafting two types of alkane octane(C_(8)H_(18))and dodecane(C_(12)H_(26))onto the surface terminals respectively.The chain-length of alkane exceeds the bond-length of surface functionalities T(x=O,-OH,-F)so as to introduce intra-flake and inter-flake strains into Ti_(3)C_(2)T_(x)MXene.The electronic microscopy(TEM/AFM)shows obvious edge-fold and tensile/compressive deformation of flake.The alkane termination increases the intrinsic absorbance of Ti_(3)C_(2)T_(x)MXene from no more than 50%up to more than 99%in the mid-wavelength in⁃frared region from 2.5μm to 4.5μm.Such an absorption enhancement attributes to the reduce of infrared reflec⁃tance of Ti_(3)C_(2)T_(x)MXene.The C-H bond skeleton vibration covers the aforementioned region and partially reduces the surface reflectance.Meanwhile,the flake deformation owing to edge-fold and tensile/compression increases the specific surface area so as to increase the absorption as well.These results have applicable value in the area of mid-infrared camouflage.展开更多
Electropulsing induced phase transformation and crystal orientation change and their effects on electrical conductivity, THz reflection and surface roughness of thin-films of Al<sub>2</sub>O<sub>3<...Electropulsing induced phase transformation and crystal orientation change and their effects on electrical conductivity, THz reflection and surface roughness of thin-films of Al<sub>2</sub>O<sub>3</sub> (2 wt%) doped ZnO were studied using XRD, SEM, AFM and Thz spectroscopy techniques. AZO-2 thin-films showed an effective response in THz spectroscopy under electropulsing. Electropulsing induced circular preferred crystal orientation changes and phase transformations were observed. The preferred crystal orientation changes accompanying decrease in stress and the secondary phase precipitation favored enhancing conductivity and THz reflection of the AZO-2 thin-films. After adequate electropulsing, both THz reflection and electrical conductivity of the thin-films were enhanced by 22.8% and 6.8%, respectively;meanwhile surface roughness reduced. The property responses of electropulsing are discussed from point view of microstructural change and dislocation dynamics.展开更多
An aqueous solution containing sodium polyacrylate（PAAS） was used in diffusive gradient in thin-films technique（DGT） to measure DGT-labile Ni2＋ concentrations.The DGT devices（PAAS DGT） were validated in four ty...An aqueous solution containing sodium polyacrylate（PAAS） was used in diffusive gradient in thin-films technique（DGT） to measure DGT-labile Ni2＋ concentrations.The DGT devices（PAAS DGT） were validated in four types of solutions,including synthetic river water containing metal ions with complexing EDTA or that without complexing EDTA,natural river water（Ling River,Jinzhou,China） spiked with Ni2＋,and an industrial wastewater （Jinzhou,China）.Results show that only free metal ions were measured by PAAS DGT,recovery=97.36% in the solutions containing only free metal ions,recovery=49.62% in a solution with metal/EDTA molar ratio of 2：1 and recovery=0 in the solutions with metal/EDTA molar ratios of 1：1 and 1：2.These indicated that the complexes of Ni-EDTA were DGT-inert.The DGT performance in spiked river water（recovery=18.24%） and in industrial wastewater（recovery=12.25%） were investigated,which indicated that the measurement of metals by this DGT device did not include the humic substances complexed fractions of metals.The binding properties of PAAS DGT for Ni2＋ were investigated under different conditions of pH value and ionic strength.Conditional stability constants（lgK） of PAAS-Ni complexes were also evaluated.展开更多
A theoretical model is developed for predicting both conduction and diffusion in thin-film ionic conductors or cables. With the linearized Poisson-Nernst-Planck(PNP)theory, the two-dimensional(2D) equations for thin i...A theoretical model is developed for predicting both conduction and diffusion in thin-film ionic conductors or cables. With the linearized Poisson-Nernst-Planck(PNP)theory, the two-dimensional(2D) equations for thin ionic conductor films are obtained from the three-dimensional(3D) equations by power series expansions in the film thickness coordinate, retaining the lower-order equations. The thin-film equations for ionic conductors are combined with similar equations for one thin dielectric film to derive the 2D equations of thin sandwich films composed of a dielectric layer and two ionic conductor layers. A sandwich film in the literature, as an ionic cable, is analyzed as an example of the equations obtained in this paper. The numerical results show the effect of diffusion in addition to the conduction treated in the literature. The obtained theoretical model including both conduction and diffusion phenomena can be used to investigate the performance of ionic-conductor devices with any frequency.展开更多
Sm-based perovskite-type oxide (SmMeO3: Me = Cr, Mn, Fe, Co) thin-films could be synthesized by a wet-chemical method using an acetylacetone—Poly(Vinyl Pyrrolidone) (PVP) polymeric precursor method at 750℃. The pero...Sm-based perovskite-type oxide (SmMeO3: Me = Cr, Mn, Fe, Co) thin-films could be synthesized by a wet-chemical method using an acetylacetone—Poly(Vinyl Pyrrolidone) (PVP) polymeric precursor method at 750℃. The perovskite-type oxide thin-films were tried to apply an acetylene gas sensor based on AC impedance spectroscopy. Among the oxides tested, SmFeO3 thin-film sensor showed good sensor responses in which the AC impedance at 20 kHz was depending on acetylene gas concentration between 2 ppm and 80 ppm at 400℃.展开更多
In this paper, three kinds of textured ZnO thin-films (the first kind has the textured structure with both columnar and polygon, the second posses pyramid-like textured structure only, and the third has the textured s...In this paper, three kinds of textured ZnO thin-films (the first kind has the textured structure with both columnar and polygon, the second posses pyramid-like textured structure only, and the third has the textured structure with both crater-like and pyramid-like), were prepared by three kinds of methods, and the application of these ZnO thin-films as a front electrode in solar cell was studied, respectively. In the first method with negative bias voltage and appropriate sputtering parameters, the textured structure with columnar and polygon on the surface of ZnO thin-film are both existence for the sample prepared by direct magnetron sputtering. Using as a front electrode in solar cell, the photoelectric conversion efficiency Eff of 7.00% was obtained. The second method is that by sputtering on the ZnO:Al self-supporting substrate, and the distribution of pyramid-like was gained. Moreover, the higher (8.25%) photoelectric conversion efficiency of solar cell was got. The last method is that by acid-etching the as-deposited ZnO thin-film which possesses mainly both columnar and polygon structure, and the textured ZnO thin-film with both crater-like and pyramid-like structure was obtained, and the photoelectric conversion efficiency of solar cell is 7.10% when using it as front electrode. These results show that the textured ZnO thin-film prepared on self-supporting substrate is more suitable for using as a front electrode in amorphous silicon cells.展开更多
We systematically investigated the detection performance of Al nanostrips for single photons at various wavelengths.The Al films were deposited using magnetron sputtering,and the sophisticated nanostructures and morph...We systematically investigated the detection performance of Al nanostrips for single photons at various wavelengths.The Al films were deposited using magnetron sputtering,and the sophisticated nanostructures and morphology of the deposited films were revealed through high-resolution transmission electron microscopy.The fabricated Al meander nanostrips,with a thickness of 4.2 nm and a width of 178 nm,exhibited a superconducting transition temperature of 2.4 K and a critical current of approximately 5μA at 0.85 K.While the Al nanostrips demonstrated a saturated internal quantum efficiency for 405-nm photons,the internal detection efficiency exhibited an exponential dependence on bias current without any saturation tendency for 1550-nm photons.This behavior can be attributed to the relatively large diffusion coefficient and coherence length of the Al films.By further narrowing the nanostrip width,the Al-SNSPDs remain capable of effectively detecting single telecom photons to facilitate practical applications.展开更多
Complementary inverter is the basic unit for logic circuits,but the inverters based on full oxide thin-film transistors(TFTs)are still very limited.The next challenge is to realize complementary inverters using homoge...Complementary inverter is the basic unit for logic circuits,but the inverters based on full oxide thin-film transistors(TFTs)are still very limited.The next challenge is to realize complementary inverters using homogeneous oxide semiconduc-tors.Herein,we propose the design of complementary inverter based on full ZnO TFTs.Li-N dual-doped ZnO(ZnO:(Li,N))acts as the p-type channel and Al-doped ZnO(ZnO:Al)serves as the n-type channel for fabrication of TFTs,and then the complemen-tary inverter is produced with p-and n-type ZnO TFTs.The homogeneous ZnO-based complementary inverter has typical volt-age transfer characteristics with the voltage gain of 13.34 at the supply voltage of 40 V.This work may open the door for the development of oxide complementary inverters for logic circuits.展开更多
Here,a preparation of stable,non-toxic,transparent,high performance zinc oxide thin-film semiconductor via thermal processing of composite system of zinc source solution filled zinc oxide nanoparticles layer was repor...Here,a preparation of stable,non-toxic,transparent,high performance zinc oxide thin-film semiconductor via thermal processing of composite system of zinc source solution filled zinc oxide nanoparticles layer was reported.The zinc oxide nanocrystals synthesized through the thermolysis of Zn-oleate complex in organic solvent medium were first deposited on the ATO/ITO/glass substrate and treated by annealing,then the zinc source solution was deposited on the zinc oxide nanoparticle layer to form precursor thin film by spin-coating process.The thin film transistor with well-controlled and densely packed nanocrystals in zinc oxide semiconductor layer was obtained by thermal annealing the system of precursor film coated ATO/ITO/glass substrate.By optimizing the fabrication conditions,the fabricated thin film transistors exhibited superior field-effect property and carrier mobility property,their saturation mobility reached 2.17 cm^(2)·V^(-1)·s^(-1),which was more than twice as high compared to the transistor devices coated only by zinc oxide nanoparticles.Our method of fabricating zinc oxide thin film transistors was simple,high efficiency,and feasible for the batch production with low cost.展开更多
The energy density of thin-film lithium batteries(TFLBs)is predominantly determined by the average voltage and specific capacity,however,the mechanism of regulating the voltage plateaus of the film electrodes is not w...The energy density of thin-film lithium batteries(TFLBs)is predominantly determined by the average voltage and specific capacity,however,the mechanism of regulating the voltage plateaus of the film electrodes is not well understood.In this study,three boride films(Co–B,Fe–B,and Co–Fe–B alloys)with different thick-nesses were fabricated to enhance the specific capacity and voltage stability of TFLBs.By analyzing the cycling performance,redox peak evolution,and capacitive contribution,the thickness-dependent lithiation behavior of the thin/thick films was elucidated.Theoretical simulations and electrochemical analysis were conducted to investigate how the lithiation behaviors affected the voltage profiles of the film electrodes.In addition,the various-thickness CoB films were compared in all-solid-state TFLBs,demonstrating the universality and practicability of this simple regulation strategy to develop high-performance energy storage devices.展开更多
The development of high-voltage tandem thin-film supercapacitors(TFSCs)has been limited by the issues such as expensive electrode materials,indispensable commercial separators and metal current collectors,and complex ...The development of high-voltage tandem thin-film supercapacitors(TFSCs)has been limited by the issues such as expensive electrode materials,indispensable commercial separators and metal current collectors,and complex manufacturing processes.Herein,we develop a potentially scalable approach to address all these issues by using CO_(2) laser pyrolysis of polyimide(PI)paper into the three-dimensional(3D)morphology of graphene paper in air.The formation process and mechanism of PI to graphene were clarified by microstructure and chemical characterizations and reaction molecular dynamics.The influences of laser scan density,power,defocus,and scan speed on the sheet resistance,longitudinal resistance,Raman spectra,and electrochemical performance of graphene papers were systematically investigated.Results indicate that high-quality graphene papers with ultralow sheet resistance(4.88Ω·square^(-1))and longitudinal resistance(3.46Ω)and extra-large crystalline size(96.1 nm)were achieved under optimized process parameters.The graphene papers can simultaneously serve as active electrode materials,current collectors,and interconnectors.The active area of electrodes is defined by a PI mask,with the help of which a hydrogel electrolyte functions as a separator.The assembled graphene paper-based TFSCs demonstrate outstanding electrochemical performance and mechanical flexibility,with the areal capacitance of 54.5 mF·cm^(-2),energy density of 10.9µWh·cm^(-2),and cycle stability retention of 86.9%over 15000 cycles.Moreover,all the tandem metal-free TFSCs,ranging from 1 to 160 cells,show excellent performance uniformity.The output voltage increases linearly from 1.2 V to 200 V.Significantly,the 160-tandem TFSCs exhibit a high voltage density within a compact volume of∼3.8 cm^(3).This work provides an avenue for achieving tandem metal-free TFSCs in a simple and efficient manner.展开更多
The agitated thin-film evaporator(ATFE)plays a crucial role in evaporation and concentration processes.The design of the scraper for processing high-viscosity non-Newtonian fluids in the ATFE is complex.The intricate ...The agitated thin-film evaporator(ATFE)plays a crucial role in evaporation and concentration processes.The design of the scraper for processing high-viscosity non-Newtonian fluids in the ATFE is complex.The intricate scraping action of the scraper introduces gas into the liquid film,leading to the formation of a gas ring along the wall.This process subsequently reduces wall heat flow,thereby affecting heat transfer.Computational fluid dynamics(CFD)is used to simulate the flow field of the non-Newtonian fluid in the ATFE.The investigation focuses on understanding the mechanism behind the formation of gas rings in the liquid film and proposes methods to prevent their formation.The results demonstrate a transition of the gas from a gas ring suspended in the liquid to a gas ring attached to the wall after entering the liquid film.The scraping action around the circumference of the scraper helps to expel gas rings,indicating the necessity of adjusting the scraper arrangement and increasing the frequency of scraping to enhance gas ring expulsion.The spiral motion of the bow wave serves as the source of gas entry into the liquid film.Therefore,the rotation speed can appropriately increase to reduce the size of the bow wave,thereby inhibiting the formation of the gas ring from the source.This research investigates the mechanism of gas ring generation and expulsion,offering theoretical guidance for processing high-viscosity non-Newtonian materials in the flow field of the ATFE.展开更多
The enhancement of mobility has always been a research focus in the field of thin-film transistors(TFTs).In this paper,we report a method using ultra-thin HfO2to improve the electrical performance of indium gallium zi...The enhancement of mobility has always been a research focus in the field of thin-film transistors(TFTs).In this paper,we report a method using ultra-thin HfO2to improve the electrical performance of indium gallium zinc oxide(IGZO)TFTs.HfO2not only repairs the surface morphology of the active layer,but also increases the carrier concentration.When the thickness of the HfO_(2) film was 3 nm,the mobility of the device was doubled(14.9 cm^(2)·V^(-1)·s^(-1)→29.6 cm^(2)·V^(-1)·s^(-1)),and the device exhibited excellent logic device performance.This paper provides a simple and effective method to enhance the electrical performance of IGZO TFTs,offering new ideas and experimental foundation for research into high-performance metal oxide(MO)TFTs.展开更多
Thin-film nanocomposite(TFN) membranes have garnered considerable attention for their potential to improve separation performance by incorporating nanomaterials. However, challenges such as these materials' uneven...Thin-film nanocomposite(TFN) membranes have garnered considerable attention for their potential to improve separation performance by incorporating nanomaterials. However, challenges such as these materials' uneven distribution and aggregation have hindered practical applications. While prior studies have largely concentrated on modifying nanosheets for compatibility with polymer matrices, the role of substrate pore size in influencing nanosheet distribution has been overlooked. In this work, MoS_(2) nanosheets were dispersed in an aqueous phase to fabricate TFN membranes, investigating the effect of substrate pore size relative to the nanosheets. By systematically varying the particle size of MoS_(2) and the pore size of the substrate, we reveal how these factors impact material distribution and structural uniformity within the membranes. Our findings reveal that larger substrate pores allow the MoS_(2)-containing monomer solution to infiltrate more effectively, minimizing nanosheet aggregation. This enhances membrane performance by promoting better dispersion. Our results underscore the importance of considering the relative size of substrate pores and nanosheets in TFN membrane design, providing a pathway to improved material integration and higher membrane efficiency.展开更多
Optical isolators,the photonic analogs of electronic diodes,are essential for ensuring the unidirectional flow of light in optical systems,thereby mitigating the destabilizing effects of back reflections.Thin-film lit...Optical isolators,the photonic analogs of electronic diodes,are essential for ensuring the unidirectional flow of light in optical systems,thereby mitigating the destabilizing effects of back reflections.Thin-film lithium niobate(TFLN),hailed as“the silicon of photonics,”has emerged as a pivotal material in the realm of chip-scale nonlinear optics,propelling the demand for compact optical isolators.We report a breakthrough in the development of a fully passive,integrated optical isolator on the TFLN platform,leveraging the Kerr effect to achieve an impressive 10.3 dB of isolation with a minimal insertion loss of 1.87 dB.Further theoretical simulations have demonstrated that our design,when applied to a microring resonator with a Q factor of 5×10^(6),can achieve 20 dB of isolation with an input power of merely 8 mW.This advancement underscores the immense potential of lithium niobate-based Kerr-effect isolators in propelling the integration and application of high-performance on-chip lasers,heralding a new era in integrated photonics.展开更多
Novel thin films consisting of optical materials such as lithium niobate and barium titanate enable various high-performance integrated photonic devices.However,the nanofabrication of these devices requires high-quali...Novel thin films consisting of optical materials such as lithium niobate and barium titanate enable various high-performance integrated photonic devices.However,the nanofabrication of these devices requires high-quality etching of these thin films,necessitating the long-term development of the fabrication recipe and specialized equipment.Here we present a strong-confinement low-index-rib-loaded waveguide structure as the building block of various passive and active integrated photonic devices based on novel thin films.By optimizing this low-index-rib-loaded waveguide structure without etching the novel thin film,we can simultaneously realize strong optical power confinement in the thin film,low optical propagation loss,and strong electro-optic coupling for the fundamental transverse electric mode.Based on our low-index-rib-loaded waveguide structure,we designed and fabricated a thin film lithium niobate(TFLN)modulator,featuring a 3-dB modulation bandwidth over 110 GHz and a voltage-length product as low as 2.26 V·cm,which is comparable to those of the state-of-the-art etched TFLN modulators.By alleviating the etching of novel thin films,the proposed structure opens up new ways of fast proof-of-concept demonstration and even mass production of high-performance integrated electro-optic and nonlinear devices based on novel thin films.展开更多
Nanoscale Ta-based diffusion barrier thin-films and Cu/barrier/Si multilayer structures were deposited on p-type Si (100) substrates by DC magnetron sputtering. Then the samples were rapidly thermal-annealed (RTA) by ...Nanoscale Ta-based diffusion barrier thin-films and Cu/barrier/Si multilayer structures were deposited on p-type Si (100) substrates by DC magnetron sputtering. Then the samples were rapidly thermal-annealed (RTA) by tungsten halide lamp. The resistance properties, structure and surface morphology of the thin-films were investigated by four-point probe (FPP) sheet resistance measurement, AFM, SEM-EDS, Alpha-Step IQ Profilers and XRD. The experimental results showed that agglomeration, oxidation and stabilization effects are concurrent. And resistance increasing and decreasing are coexistent after RTA. The formation of high resistance Cu3Si due to inter-diffusion between Cu and Si and more intensive electron scattering resulting from rougher surface caused the sheet resistance to increase abruptly after high temperature RTA.展开更多
This study investigates the carrier transport of heterojunction channel in oxide semiconductor thin-film transistor(TFT)using the elevated-metal metal-oxide(EMMO)architecture and indium−zinc oxide(InZnO).The heterojun...This study investigates the carrier transport of heterojunction channel in oxide semiconductor thin-film transistor(TFT)using the elevated-metal metal-oxide(EMMO)architecture and indium−zinc oxide(InZnO).The heterojunction band diagram of InZnO bilayer was modified by the cation composition to form the two-dimensional electron gas(2DEG)at the interface quantum well,as verified using a metal−insulator−semiconductor(MIS)device.Although the 2DEG indeed contributes to a higher mobility than the monolayer channel,the competition and cooperation between the gate field and the built-in field strongly affect such mobility-boosting effect,originating from the carrier inelastic collision at the heterojunction interface and the gate field-induced suppression of quantum well.Benefited from the proper energy-band engineering,a high mobility of 84.3 cm2·V^(−1)·s^(−1),a decent threshold voltage(V_(th))of−6.5 V,and a steep subthreshold swing(SS)of 0.29 V/dec were obtained in InZnO-based heterojunction TFT.展开更多
文摘The effects of long-term moisture changes on the migration,release,and bioavailability of selenium in soil are complex.Due to the lack of effective monitoring methods for precise quantification,its dynamic behavior is still unclear.Based on the DGT(Diffusive Gradients in Thin-films)technology,this study sets up three moisture control scenarios:continuous wet,wet-dry alternating,and continuous dry,and carries out a 6-month soil moisture control experiment.In the experiment,the DGT device collected the diffusion gradient data of soil selenium under different scenarios,and analyzed the migration characteristics of selenium in combination with the adsorption isotherm.Meanwhile,the release rate,migration coefficient,and bioavailability parameters of selenium are calculated by fitting the first-order kinetic model,further verifying the reliability and applicability of the DGT data.The experimental results demonstrate that under continuous wet conditions,the release rate of soil selenium reaches 1.85µg·cm^(-2)·h^(-1),with a migration coefficient of 0.012 cm^(2)·h^(-1)and a bioavailability parameter of 0.74;under wet-dry alternating conditions,they are 1.42µg·cm^(-2)·h^(-1),0.01 cm^(2)·h^(-1),and 0.68,respectively;under continuous dry conditions,the release rate of soil selenium is the smallest,at 0.88µg·cm^(-2)·h^(-1),with a migration coefficient of 0.004 cm^(-2)·h^(-1)and a bioavailability parameter of 0.5.The results of this experiment reveal the dynamic behavior of soil selenium under different moisture conditions and reflect the high efficiency of DGT technology in dynamic monitoring and quantitative analysis of soil selenium behavior,providing a scientific basis for the optimal management of rhizosphere soil selenium.
文摘We report the performances of a chalcopyrite Cu(In, Ga)Se<sub>2 </sub>CIGS-based thin-film solar cell with a newly employed high conductive n-Si layer. The data analysis was performed with the help of the 1D-Solar Cell Capacitance Simulator (1D-SCAPS) software program. The new device structure is based on the CIGS layer as the absorber layer, n-Si as the high conductive layer, i-In<sub>2</sub>S<sub>3</sub>, and i-ZnO as the buffer and window layers, respectively. The optimum CIGS bandgap was determined first and used to simulate and analyze the cell performance throughout the experiment. This analysis revealed that the absorber layer’s optimum bandgap value has to be 1.4 eV to achieve maximum efficiency of 22.57%. Subsequently, output solar cell parameters were analyzed as a function of CIGS layer thickness, defect density, and the operating temperature with an optimized n-Si layer. The newly modeled device has a p-CIGS/n-Si/In<sub>2</sub>S<sub>3</sub>/Al-ZnO structure. The main objective was to improve the overall cell performance while optimizing the thickness of absorber layers, defect density, bandgap, and operating temperature with the newly employed optimized n-Si layer. The increase of absorber layer thickness from 0.2 - 2 µm showed an upward trend in the cell’s performance, while the increase of defect density and operating temperature showed a downward trend in solar cell performance. This study illustrates that the proposed cell structure shows higher cell performances and can be fabricated on the lab-scale and industrial levels.
文摘An enhancement of mid-wavelength infrared absorbance is achieved via a cost-effectively chemical method to bend the flakes by grafting two types of alkane octane(C_(8)H_(18))and dodecane(C_(12)H_(26))onto the surface terminals respectively.The chain-length of alkane exceeds the bond-length of surface functionalities T(x=O,-OH,-F)so as to introduce intra-flake and inter-flake strains into Ti_(3)C_(2)T_(x)MXene.The electronic microscopy(TEM/AFM)shows obvious edge-fold and tensile/compressive deformation of flake.The alkane termination increases the intrinsic absorbance of Ti_(3)C_(2)T_(x)MXene from no more than 50%up to more than 99%in the mid-wavelength in⁃frared region from 2.5μm to 4.5μm.Such an absorption enhancement attributes to the reduce of infrared reflec⁃tance of Ti_(3)C_(2)T_(x)MXene.The C-H bond skeleton vibration covers the aforementioned region and partially reduces the surface reflectance.Meanwhile,the flake deformation owing to edge-fold and tensile/compression increases the specific surface area so as to increase the absorption as well.These results have applicable value in the area of mid-infrared camouflage.
文摘Electropulsing induced phase transformation and crystal orientation change and their effects on electrical conductivity, THz reflection and surface roughness of thin-films of Al<sub>2</sub>O<sub>3</sub> (2 wt%) doped ZnO were studied using XRD, SEM, AFM and Thz spectroscopy techniques. AZO-2 thin-films showed an effective response in THz spectroscopy under electropulsing. Electropulsing induced circular preferred crystal orientation changes and phase transformations were observed. The preferred crystal orientation changes accompanying decrease in stress and the secondary phase precipitation favored enhancing conductivity and THz reflection of the AZO-2 thin-films. After adequate electropulsing, both THz reflection and electrical conductivity of the thin-films were enhanced by 22.8% and 6.8%, respectively;meanwhile surface roughness reduced. The property responses of electropulsing are discussed from point view of microstructural change and dislocation dynamics.
文摘An aqueous solution containing sodium polyacrylate（PAAS） was used in diffusive gradient in thin-films technique（DGT） to measure DGT-labile Ni2＋ concentrations.The DGT devices（PAAS DGT） were validated in four types of solutions,including synthetic river water containing metal ions with complexing EDTA or that without complexing EDTA,natural river water（Ling River,Jinzhou,China） spiked with Ni2＋,and an industrial wastewater （Jinzhou,China）.Results show that only free metal ions were measured by PAAS DGT,recovery=97.36% in the solutions containing only free metal ions,recovery=49.62% in a solution with metal/EDTA molar ratio of 2：1 and recovery=0 in the solutions with metal/EDTA molar ratios of 1：1 and 1：2.These indicated that the complexes of Ni-EDTA were DGT-inert.The DGT performance in spiked river water（recovery=18.24%） and in industrial wastewater（recovery=12.25%） were investigated,which indicated that the measurement of metals by this DGT device did not include the humic substances complexed fractions of metals.The binding properties of PAAS DGT for Ni2＋ were investigated under different conditions of pH value and ionic strength.Conditional stability constants（lgK） of PAAS-Ni complexes were also evaluated.
基金Project supported by the National Natural Science Foundation of China(Nos.11672265,11202182,and 11621062)the Fundamental Research Funds for the Central Universities(Nos.2016QNA4026 and2016XZZX001-05)the Open Foundation of Zhejiang Provincial Top Key Discipline of Mechanical Engineering
文摘A theoretical model is developed for predicting both conduction and diffusion in thin-film ionic conductors or cables. With the linearized Poisson-Nernst-Planck(PNP)theory, the two-dimensional(2D) equations for thin ionic conductor films are obtained from the three-dimensional(3D) equations by power series expansions in the film thickness coordinate, retaining the lower-order equations. The thin-film equations for ionic conductors are combined with similar equations for one thin dielectric film to derive the 2D equations of thin sandwich films composed of a dielectric layer and two ionic conductor layers. A sandwich film in the literature, as an ionic cable, is analyzed as an example of the equations obtained in this paper. The numerical results show the effect of diffusion in addition to the conduction treated in the literature. The obtained theoretical model including both conduction and diffusion phenomena can be used to investigate the performance of ionic-conductor devices with any frequency.
文摘Sm-based perovskite-type oxide (SmMeO3: Me = Cr, Mn, Fe, Co) thin-films could be synthesized by a wet-chemical method using an acetylacetone—Poly(Vinyl Pyrrolidone) (PVP) polymeric precursor method at 750℃. The perovskite-type oxide thin-films were tried to apply an acetylene gas sensor based on AC impedance spectroscopy. Among the oxides tested, SmFeO3 thin-film sensor showed good sensor responses in which the AC impedance at 20 kHz was depending on acetylene gas concentration between 2 ppm and 80 ppm at 400℃.
文摘In this paper, three kinds of textured ZnO thin-films (the first kind has the textured structure with both columnar and polygon, the second posses pyramid-like textured structure only, and the third has the textured structure with both crater-like and pyramid-like), were prepared by three kinds of methods, and the application of these ZnO thin-films as a front electrode in solar cell was studied, respectively. In the first method with negative bias voltage and appropriate sputtering parameters, the textured structure with columnar and polygon on the surface of ZnO thin-film are both existence for the sample prepared by direct magnetron sputtering. Using as a front electrode in solar cell, the photoelectric conversion efficiency Eff of 7.00% was obtained. The second method is that by sputtering on the ZnO:Al self-supporting substrate, and the distribution of pyramid-like was gained. Moreover, the higher (8.25%) photoelectric conversion efficiency of solar cell was got. The last method is that by acid-etching the as-deposited ZnO thin-film which possesses mainly both columnar and polygon structure, and the textured ZnO thin-film with both crater-like and pyramid-like structure was obtained, and the photoelectric conversion efficiency of solar cell is 7.10% when using it as front electrode. These results show that the textured ZnO thin-film prepared on self-supporting substrate is more suitable for using as a front electrode in amorphous silicon cells.
基金Strategic Priority Research Program(B)of the Chinese Academy of Sciences(XDB0580000)Youth Innovation Promotion Association of the Chinese Academy of Sciences(2021230)+2 种基金Shanghai Science and Technology Development Foundation(21YF1455500)Science and Technology Commission of Shanghai Municipality(2019SHZDZX01)National Natural Science Foundation of China(61801462,61827823,61971408).
文摘We systematically investigated the detection performance of Al nanostrips for single photons at various wavelengths.The Al films were deposited using magnetron sputtering,and the sophisticated nanostructures and morphology of the deposited films were revealed through high-resolution transmission electron microscopy.The fabricated Al meander nanostrips,with a thickness of 4.2 nm and a width of 178 nm,exhibited a superconducting transition temperature of 2.4 K and a critical current of approximately 5μA at 0.85 K.While the Al nanostrips demonstrated a saturated internal quantum efficiency for 405-nm photons,the internal detection efficiency exhibited an exponential dependence on bias current without any saturation tendency for 1550-nm photons.This behavior can be attributed to the relatively large diffusion coefficient and coherence length of the Al films.By further narrowing the nanostrip width,the Al-SNSPDs remain capable of effectively detecting single telecom photons to facilitate practical applications.
基金supported by Zhejiang Provincial Natural Science Foundation of China(No.LZ24E020001).
文摘Complementary inverter is the basic unit for logic circuits,but the inverters based on full oxide thin-film transistors(TFTs)are still very limited.The next challenge is to realize complementary inverters using homogeneous oxide semiconduc-tors.Herein,we propose the design of complementary inverter based on full ZnO TFTs.Li-N dual-doped ZnO(ZnO:(Li,N))acts as the p-type channel and Al-doped ZnO(ZnO:Al)serves as the n-type channel for fabrication of TFTs,and then the complemen-tary inverter is produced with p-and n-type ZnO TFTs.The homogeneous ZnO-based complementary inverter has typical volt-age transfer characteristics with the voltage gain of 13.34 at the supply voltage of 40 V.This work may open the door for the development of oxide complementary inverters for logic circuits.
文摘Here,a preparation of stable,non-toxic,transparent,high performance zinc oxide thin-film semiconductor via thermal processing of composite system of zinc source solution filled zinc oxide nanoparticles layer was reported.The zinc oxide nanocrystals synthesized through the thermolysis of Zn-oleate complex in organic solvent medium were first deposited on the ATO/ITO/glass substrate and treated by annealing,then the zinc source solution was deposited on the zinc oxide nanoparticle layer to form precursor thin film by spin-coating process.The thin film transistor with well-controlled and densely packed nanocrystals in zinc oxide semiconductor layer was obtained by thermal annealing the system of precursor film coated ATO/ITO/glass substrate.By optimizing the fabrication conditions,the fabricated thin film transistors exhibited superior field-effect property and carrier mobility property,their saturation mobility reached 2.17 cm^(2)·V^(-1)·s^(-1),which was more than twice as high compared to the transistor devices coated only by zinc oxide nanoparticles.Our method of fabricating zinc oxide thin film transistors was simple,high efficiency,and feasible for the batch production with low cost.
基金supported by National Natural Science Foundation of China(Grant Nos.52101273 and U22A20118)Natural Science Foundation of Fujian Province of China(Grant No.2022J01042)Fundamental Research Funds for Central Universities of China(Grant No.20720242002).
文摘The energy density of thin-film lithium batteries(TFLBs)is predominantly determined by the average voltage and specific capacity,however,the mechanism of regulating the voltage plateaus of the film electrodes is not well understood.In this study,three boride films(Co–B,Fe–B,and Co–Fe–B alloys)with different thick-nesses were fabricated to enhance the specific capacity and voltage stability of TFLBs.By analyzing the cycling performance,redox peak evolution,and capacitive contribution,the thickness-dependent lithiation behavior of the thin/thick films was elucidated.Theoretical simulations and electrochemical analysis were conducted to investigate how the lithiation behaviors affected the voltage profiles of the film electrodes.In addition,the various-thickness CoB films were compared in all-solid-state TFLBs,demonstrating the universality and practicability of this simple regulation strategy to develop high-performance energy storage devices.
基金funded by the National Natural Science Foundation of China(Grant Nos.52205457 and 52422511)the National Key R&D Program of China(Grant No.2022YFB4701000)+3 种基金the Guangdong Basic and Applied Basic Research Foundation,China(Grant Nos.2024A1515010043,2025A1515010890 and 2022B1515120011)the Young Talent Support Project of Guangzhou Association for Science and Technology(Grant No.QT2024-010)the Guangzhou Basic and Applied Basic Research Foundation(Grant No.SL2024A04J01501)the State Key Laboratory of Precision Electronic Manufacturing Technology and Equipment(Grant No.JMDZ202303).
文摘The development of high-voltage tandem thin-film supercapacitors(TFSCs)has been limited by the issues such as expensive electrode materials,indispensable commercial separators and metal current collectors,and complex manufacturing processes.Herein,we develop a potentially scalable approach to address all these issues by using CO_(2) laser pyrolysis of polyimide(PI)paper into the three-dimensional(3D)morphology of graphene paper in air.The formation process and mechanism of PI to graphene were clarified by microstructure and chemical characterizations and reaction molecular dynamics.The influences of laser scan density,power,defocus,and scan speed on the sheet resistance,longitudinal resistance,Raman spectra,and electrochemical performance of graphene papers were systematically investigated.Results indicate that high-quality graphene papers with ultralow sheet resistance(4.88Ω·square^(-1))and longitudinal resistance(3.46Ω)and extra-large crystalline size(96.1 nm)were achieved under optimized process parameters.The graphene papers can simultaneously serve as active electrode materials,current collectors,and interconnectors.The active area of electrodes is defined by a PI mask,with the help of which a hydrogel electrolyte functions as a separator.The assembled graphene paper-based TFSCs demonstrate outstanding electrochemical performance and mechanical flexibility,with the areal capacitance of 54.5 mF·cm^(-2),energy density of 10.9µWh·cm^(-2),and cycle stability retention of 86.9%over 15000 cycles.Moreover,all the tandem metal-free TFSCs,ranging from 1 to 160 cells,show excellent performance uniformity.The output voltage increases linearly from 1.2 V to 200 V.Significantly,the 160-tandem TFSCs exhibit a high voltage density within a compact volume of∼3.8 cm^(3).This work provides an avenue for achieving tandem metal-free TFSCs in a simple and efficient manner.
基金National Natural Science Foundation of China(No.51905089)Fundamental Research Funds for the Central Universities,China(No.2232020D-31)。
文摘The agitated thin-film evaporator(ATFE)plays a crucial role in evaporation and concentration processes.The design of the scraper for processing high-viscosity non-Newtonian fluids in the ATFE is complex.The intricate scraping action of the scraper introduces gas into the liquid film,leading to the formation of a gas ring along the wall.This process subsequently reduces wall heat flow,thereby affecting heat transfer.Computational fluid dynamics(CFD)is used to simulate the flow field of the non-Newtonian fluid in the ATFE.The investigation focuses on understanding the mechanism behind the formation of gas rings in the liquid film and proposes methods to prevent their formation.The results demonstrate a transition of the gas from a gas ring suspended in the liquid to a gas ring attached to the wall after entering the liquid film.The scraping action around the circumference of the scraper helps to expel gas rings,indicating the necessity of adjusting the scraper arrangement and increasing the frequency of scraping to enhance gas ring expulsion.The spiral motion of the bow wave serves as the source of gas entry into the liquid film.Therefore,the rotation speed can appropriately increase to reduce the size of the bow wave,thereby inhibiting the formation of the gas ring from the source.This research investigates the mechanism of gas ring generation and expulsion,offering theoretical guidance for processing high-viscosity non-Newtonian materials in the flow field of the ATFE.
基金Project supported by the National Natural Science Foundation of China(Grant No.62441407)the Natural Science Basic Research Program of Shaanxi(Grant No.2024JCYBQN-0631)+1 种基金the Natural Science Foundation of Shaanxi Provincial Department of Education(Grant No.23JK0482)the Shaanxi Province Key R&D Program General Project-Industrial Field(Grant No.2024GX-YBXM-085)。
文摘The enhancement of mobility has always been a research focus in the field of thin-film transistors(TFTs).In this paper,we report a method using ultra-thin HfO2to improve the electrical performance of indium gallium zinc oxide(IGZO)TFTs.HfO2not only repairs the surface morphology of the active layer,but also increases the carrier concentration.When the thickness of the HfO_(2) film was 3 nm,the mobility of the device was doubled(14.9 cm^(2)·V^(-1)·s^(-1)→29.6 cm^(2)·V^(-1)·s^(-1)),and the device exhibited excellent logic device performance.This paper provides a simple and effective method to enhance the electrical performance of IGZO TFTs,offering new ideas and experimental foundation for research into high-performance metal oxide(MO)TFTs.
基金financially supported by the National Natural Science Foundation of China (No. 22076075)Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control (No. 2023B1212060002)+1 种基金the Key Program of Fundamental Research from the Shenzhen Science and Technology Innovation Commission (No. JCYJ20220818100218039)the General Program of Fundamental Research from the Shenzhen Science and Technology Innovation Commission (No. JCY20230807092500001)。
文摘Thin-film nanocomposite(TFN) membranes have garnered considerable attention for their potential to improve separation performance by incorporating nanomaterials. However, challenges such as these materials' uneven distribution and aggregation have hindered practical applications. While prior studies have largely concentrated on modifying nanosheets for compatibility with polymer matrices, the role of substrate pore size in influencing nanosheet distribution has been overlooked. In this work, MoS_(2) nanosheets were dispersed in an aqueous phase to fabricate TFN membranes, investigating the effect of substrate pore size relative to the nanosheets. By systematically varying the particle size of MoS_(2) and the pore size of the substrate, we reveal how these factors impact material distribution and structural uniformity within the membranes. Our findings reveal that larger substrate pores allow the MoS_(2)-containing monomer solution to infiltrate more effectively, minimizing nanosheet aggregation. This enhances membrane performance by promoting better dispersion. Our results underscore the importance of considering the relative size of substrate pores and nanosheets in TFN membrane design, providing a pathway to improved material integration and higher membrane efficiency.
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2022YFF0712800 and 2019YFA0308700)。
文摘Optical isolators,the photonic analogs of electronic diodes,are essential for ensuring the unidirectional flow of light in optical systems,thereby mitigating the destabilizing effects of back reflections.Thin-film lithium niobate(TFLN),hailed as“the silicon of photonics,”has emerged as a pivotal material in the realm of chip-scale nonlinear optics,propelling the demand for compact optical isolators.We report a breakthrough in the development of a fully passive,integrated optical isolator on the TFLN platform,leveraging the Kerr effect to achieve an impressive 10.3 dB of isolation with a minimal insertion loss of 1.87 dB.Further theoretical simulations have demonstrated that our design,when applied to a microring resonator with a Q factor of 5×10^(6),can achieve 20 dB of isolation with an input power of merely 8 mW.This advancement underscores the immense potential of lithium niobate-based Kerr-effect isolators in propelling the integration and application of high-performance on-chip lasers,heralding a new era in integrated photonics.
基金financial supports from National Key Research and Development Program of China (2021YFA1401000)National Natural Science Foundation of China (62435009)+2 种基金Beijing Municipal Natural Science Foundation (Z220008)Zhuhai Industry University Research Collaboration Project (ZH-2201700121010)supported by the Center of High Performance Computing,Tsinghua University
文摘Novel thin films consisting of optical materials such as lithium niobate and barium titanate enable various high-performance integrated photonic devices.However,the nanofabrication of these devices requires high-quality etching of these thin films,necessitating the long-term development of the fabrication recipe and specialized equipment.Here we present a strong-confinement low-index-rib-loaded waveguide structure as the building block of various passive and active integrated photonic devices based on novel thin films.By optimizing this low-index-rib-loaded waveguide structure without etching the novel thin film,we can simultaneously realize strong optical power confinement in the thin film,low optical propagation loss,and strong electro-optic coupling for the fundamental transverse electric mode.Based on our low-index-rib-loaded waveguide structure,we designed and fabricated a thin film lithium niobate(TFLN)modulator,featuring a 3-dB modulation bandwidth over 110 GHz and a voltage-length product as low as 2.26 V·cm,which is comparable to those of the state-of-the-art etched TFLN modulators.By alleviating the etching of novel thin films,the proposed structure opens up new ways of fast proof-of-concept demonstration and even mass production of high-performance integrated electro-optic and nonlinear devices based on novel thin films.
基金the National Natural Science Foundation of China (Grant No. 60371046)
文摘Nanoscale Ta-based diffusion barrier thin-films and Cu/barrier/Si multilayer structures were deposited on p-type Si (100) substrates by DC magnetron sputtering. Then the samples were rapidly thermal-annealed (RTA) by tungsten halide lamp. The resistance properties, structure and surface morphology of the thin-films were investigated by four-point probe (FPP) sheet resistance measurement, AFM, SEM-EDS, Alpha-Step IQ Profilers and XRD. The experimental results showed that agglomeration, oxidation and stabilization effects are concurrent. And resistance increasing and decreasing are coexistent after RTA. The formation of high resistance Cu3Si due to inter-diffusion between Cu and Si and more intensive electron scattering resulting from rougher surface caused the sheet resistance to increase abruptly after high temperature RTA.
基金supported by National Key Research and Development Program(2021YFB3600802)Shenzhen Municipal Scientific Program(JSGG20220831103803007,SGDX20211123145404006)Guangdong Basic and Applied Basic Research Foundation(2022A1515110029)
文摘This study investigates the carrier transport of heterojunction channel in oxide semiconductor thin-film transistor(TFT)using the elevated-metal metal-oxide(EMMO)architecture and indium−zinc oxide(InZnO).The heterojunction band diagram of InZnO bilayer was modified by the cation composition to form the two-dimensional electron gas(2DEG)at the interface quantum well,as verified using a metal−insulator−semiconductor(MIS)device.Although the 2DEG indeed contributes to a higher mobility than the monolayer channel,the competition and cooperation between the gate field and the built-in field strongly affect such mobility-boosting effect,originating from the carrier inelastic collision at the heterojunction interface and the gate field-induced suppression of quantum well.Benefited from the proper energy-band engineering,a high mobility of 84.3 cm2·V^(−1)·s^(−1),a decent threshold voltage(V_(th))of−6.5 V,and a steep subthreshold swing(SS)of 0.29 V/dec were obtained in InZnO-based heterojunction TFT.
