Titanium plates with a Ti−O solid solution surface-hardened layer were cold roll-bonded with 304 stainless steel plates with high work hardening rates.The evolution and mechanisms affecting the interfacial bonding str...Titanium plates with a Ti−O solid solution surface-hardened layer were cold roll-bonded with 304 stainless steel plates with high work hardening rates.The evolution and mechanisms affecting the interfacial bonding strength in titanium/stainless steel laminated composites were investigated.Results indicate that the hardened layer reduces the interfacial bonding strength from over 261 MPa to less than 204 MPa.During the cold roll-bonding process,the hardened layer fractures,leading to the formation of multi-scale cracks that are difficult for the stainless steel to fill.This not only hinders the development of an interlocking interface but also leads to the presence of numerous microcracks and hardened blocks along the nearly straight interface,consequently weakening the interfacial bonding strength.In metals with high work hardening rates,the conventional approach of enhancing interface interlocking and improving interfacial bonding strength by using a surface-hardened layer becomes less effective.展开更多
The adsorption isotherm of sodium polyacrylate on dicalcium silicate（2CaO-SiO2） in sodium aluminate solution at 80 ℃ was studied.The type of surface adsorption of sodium polyacrylate is saturated adsorption,and the...The adsorption isotherm of sodium polyacrylate on dicalcium silicate（2CaO-SiO2） in sodium aluminate solution at 80 ℃ was studied.The type of surface adsorption of sodium polyacrylate is saturated adsorption,and the adsorption behavior belongs to L-type,according with the monolayer adsorption model of Langmuir equation.The surface coverage of sodium polyacrylate is 1.06 mol/μm2.The relation curve between the surface pressure and the molecular area of adsorption film was obtained by Gibbs formula.The variation of interfacial energy caused by adsorption as well as the relationship between the relation curve and the type of adsorption was discussed.展开更多
Silicon stands as a key anode material in lithium-ion battery ascribing to its high energy density.Nevertheless,the poor rate performance and limited cycling life remain unresolved through conventional approaches that...Silicon stands as a key anode material in lithium-ion battery ascribing to its high energy density.Nevertheless,the poor rate performance and limited cycling life remain unresolved through conventional approaches that involve carbon composites or nanostructures,primarily due to the un-controllable effects arising from the substantial formation of a solid electrolyte interphase(SEI)during the cycling.Here,an ultra-thin and homogeneous Ti doping alumina oxide catalytic interface is meticulously applied on the porous Si through a synergistic etching and hydrolysis process.This defect-rich oxide interface promotes a selective adsorption of fluoroethylene carbonate,leading to a catalytic reaction that can be aptly described as“molecular concentration-in situ conversion”.The resultant inorganic-rich SEI layer is electrochemical stable and favors ion-transport,particularly at high-rate cycling and high temperature.The robustly shielded porous Si,with a large surface area,achieves a high initial Coulombic efficiency of 84.7%and delivers exceptional high-rate performance at 25 A g^(−1)(692 mAh g^(−1))and a high Coulombic efficiency of 99.7%over 1000 cycles.The robust SEI constructed through a precious catalytic layer promises significant advantages for the fast development of silicon-based anode in fast-charging batteries.展开更多
This paper presents an exact solution for the transverse interface crack in the plane strain case. The crack is perpendicular to the interface and in one material. The exact complex stress functions are first obtained...This paper presents an exact solution for the transverse interface crack in the plane strain case. The crack is perpendicular to the interface and in one material. The exact complex stress functions are first obtained with some unknown constants. The satisfactions of all boundary conditions are then checked, the condition at infinity is considered and the unknown constants are determined. Further study may focus on the case with different shear moduli and the influence of the large deformation.展开更多
For the diffusion-controlled adsorption, the expression of dynamic surface adsorption P（t） was ob- tained by solving the diffusion equation. Two cases, i.e. the short and long time limits, were mainly discussed in t...For the diffusion-controlled adsorption, the expression of dynamic surface adsorption P（t） was ob- tained by solving the diffusion equation. Two cases, i.e. the short and long time limits, were mainly discussed in this paper. From the measured dynamic surface tension of aqueous surfactant sodium dodecyl sulfate （SDS） solutions at 25 ℃, the adsorption kinetics of SDS at air/solution interface was studied. It was proved that for both of the short and long time limits, the adsorption process of SDS was controlled by diffusion.展开更多
Membrane/solution interface consists of a neutral concentration polai layer(CPL) and a charge layer(CL) under external electrical field, and the neutral CPL can be neglected under high frequency AC electrical field. T...Membrane/solution interface consists of a neutral concentration polai layer(CPL) and a charge layer(CL) under external electrical field, and the neutral CPL can be neglected under high frequency AC electrical field. The relationship of CL thickness e with electrolyte concentration C and fixed ion exchange sites density σ in membrane surface layer can be expressed as e展开更多
In this paper a pH microprobe technique was developed to measure in-situ the pH value at the electrode/solution interface. Iridium oxide was used as a pH sensitive material with good response behavior in the measured ...In this paper a pH microprobe technique was developed to measure in-situ the pH value at the electrode/solution interface. Iridium oxide was used as a pH sensitive material with good response behavior in the measured solutions. The experimental results indicated that the interfacial pH increased with the applied potential, first jumped to a maximum, then slowly decreased at the controlled potential during the electrodeposition process of functional ceramics.展开更多
In this paper, we first find finite travelling-wave solutions, and then investigate the short time development of interfaces for non-Newtonian diffusion equations with strong absorption. We show that the initial behav...In this paper, we first find finite travelling-wave solutions, and then investigate the short time development of interfaces for non-Newtonian diffusion equations with strong absorption. We show that the initial behavior of the interface depends on the concentration of the mass of u（x,0） near x=0. More precisely, we find a critical value of the concentration, which separates the heating front of interfaces from the cooling front of them.展开更多
In situ x-ray diffraction electrochemical method is used to study the activation of silver electrode in KCl solution and UPD lead on silver electrode surface. We found that the activation makes the silver crystal thic...In situ x-ray diffraction electrochemical method is used to study the activation of silver electrode in KCl solution and UPD lead on silver electrode surface. We found that the activation makes the silver crystal thicker in (111), and the arrangement of water molecules on the silver electrode surface with UPD lead is partially ordered.展开更多
Single-entity collisional electrochemistry(SECE)is a branch of single-entity electrochemistry.It can directly characterize entities/particles with single particle resolution through random collisions between particles...Single-entity collisional electrochemistry(SECE)is a branch of single-entity electrochemistry.It can directly characterize entities/particles with single particle resolution through random collisions between particles and electrodes in a solution,and obtain rich physicochemical information,thus becoming one of the frontiers of electroanalytical chemistry in the past two decades.Interestingly,the(micro/nanoscale)sensing electrodes have evolved from a polarizable liquid/liquid(mercury/liquid)interface to a solid/liquid interface and then to a liquid/liquid interface(i.e.,an interface between twoimmiscible electrolyte solutions,ITIES),as if they have completed a cycle(but in fact they have not).ITIES has become the latest sensing electrode in the booming SECE due to its polarizability(up to 1.1 V at the water/a,a,a-trifluorotoluene interface)and high reproducibility.The four measurement modes(direct electrolysis,mediated electrolysis,current blockade,and charge displacement)developed in the realm of SECE at solid/liquid interfaces have also been fully realized at the miniature ITIES.This article will discuss these four modes at the ITIES from the perspectives of basic concepts,operating mechanisms,and latest developments(e.g.,discovery of ionosomes,blockade effect of Faradaic ion transfer,etc.),and look forward to the future development and direction of this emerging field.展开更多
In this paper, the eigen function expansions of displacements and stresses of bi-metal laminates with interface cracks are obtained. Furthermore, the stress intensity factors are determined by the variational method t...In this paper, the eigen function expansions of displacements and stresses of bi-metal laminates with interface cracks are obtained. Furthermore, the stress intensity factors are determined by the variational method to satisfy the boundary conditions and there are only line integrals in the variational equations due to the previous satisfaction of all basic equations. The computations show that this method of solution has the advantages of rapid convergency and time-saving. The results obtained by this method for homogeneous material agree with the known ones very well.展开更多
Based on the microscopic phase-field model, ordered domain interfaces formed between D022 （Ni3V） phases along [001] direction in Ni75AlxV25-x alloys were simulated, and the effects of atomic structure on the migrati...Based on the microscopic phase-field model, ordered domain interfaces formed between D022 （Ni3V） phases along [001] direction in Ni75AlxV25-x alloys were simulated, and the effects of atomic structure on the migration characteristic and solute segregation of interfaces were studied. It is found that the migration ability is related to the atomic structure of interfaces, and three kinds of interfaces can migrate except the interface （001）//（002） which has the characteristic of L12 （Ni3Al） structure. V atoms jump to the nearest neighbor site and substitute for Ni, and vice versa. Because of the site selectivity behaviors of jumping atoms, the number of jumping atoms during the migration is the least and the jumping distance of atoms is the shortest among all possible modes, and the atomic structures of interfaces are unchanged before and after the migration. The preferences and degree of segregation or depletion of alloy elements are also related to the atomic structure of interface.展开更多
Currently, a conventional two-step method has been used to generate black silicon （BS） surfaces on silicon substrates for solar cell manufacturing. However, the performances of the solar cell made with such surface ...Currently, a conventional two-step method has been used to generate black silicon （BS） surfaces on silicon substrates for solar cell manufacturing. However, the performances of the solar cell made with such surface generation method are poor, because of the high surface recombination caused by deep etching in the conventional surface generation method for BS. In this work, a modified wet chemical etching solution with additives was developed. A homogeneous BS layer with random porous structure was obtained from the modified solution in only one step at room temperature. The BS layer had low reflectivity and shallow etching depth. The additive in the etch solution performs the function of pH-modulation. After 16-min etching, the etching depth in the samples was approximately 200 nm, and the spectrum-weighted-reflectivity in the range from 300 nm to 1200 nm was below 5%. BS solar cells were fabricated in the production line. The decreased etching depth can improve the electrical performance of solar cells because of the decrease in surface recombination. An efficiency of 15.63% for the modified etching BS solar cells was achieved on a large area, p- type single crystalline silicon substrate with a 624.32-mV open circuit voltage and a 77.88% fill factor.展开更多
By inserting a thin highly doped crystalline silicon layer between the base region and amorphous silicon layer in an interdigitated back-contact （IBC） silicon solar cell, a new passivation layer is investigated. The...By inserting a thin highly doped crystalline silicon layer between the base region and amorphous silicon layer in an interdigitated back-contact （IBC） silicon solar cell, a new passivation layer is investigated. The passivation layer performance is characterized by numerical simulations. Moreover, the dependence of the output parameters of the solar cell on the additional layer parameters （doping concentration and thickness） is studied. By optimizing the additional passivation layer in terms of doping concentration and thickness, the power conversion efficiency could be improved by a factor of 2.5%, open circuit voltage is increased by 30 mV and the fill factor of the solar cell by 7.4%. The performance enhancement is achieved due to the decrease of recombination rate, a decrease in solar cell resistivity and improvement of field effect passivation at heterojunction interface. The above-mentioned results are compared with reported results of the same conventional interdigitated back-contact silicon solar cell structure. Furthermore, the effect of a-Si：H/c-Si interface defect density on IBC silicon solar cell parameters with a new passivation layer is studied. The additional passivation layer also reduces the sensitivity of output parameter of solar cell to interface defect density.展开更多
One problem associated with microcavity devices is the significant difference between the reflection spectra of fabricated porous silicon microcavity(PSM) devices and those obtained by theoretical calculation of ideal...One problem associated with microcavity devices is the significant difference between the reflection spectra of fabricated porous silicon microcavity(PSM) devices and those obtained by theoretical calculation of ideal microcavity devices.To address this problem, studies were carried out to determine the effects of the refractive index dispersion, the absorption of the porous silicon layer and the fluctuation of the dielectric interface on the reflection spectra of PSM devices.The results are in good agreement with those obtained experimentally from the fabricated PSM devices, which provides a theoretical basis for the design of PSM sensors.展开更多
The present work focused on corrosion inhibition of AA6063 type Al-Mg-Si alloy in sodium chloride （NaCI） solution with a silicon carbide inhibitor, using the potentiodynamic electrochemical method. The aluminium all...The present work focused on corrosion inhibition of AA6063 type Al-Mg-Si alloy in sodium chloride （NaCI） solution with a silicon carbide inhibitor, using the potentiodynamic electrochemical method. The aluminium alloy surface morphology was examined, in the as-received and as-corroded in the un-inhibited state, with scanning electron microscopy equipped with energy dispersive spectroscopy （SEM-EDS）. The results obtained via linear polarization indicated a high corrosion potential for the unprotected as-received alloy. Equally, inhibition efficiency as high as 98.82% at 10.0 g/v silicon carbide addition was obtained with increased polarization resistance fRy）, while the current density reduced significantly for inhibited samples compared to the un-inhibited aluminium alloy. The adsorption mechanism of the inhibitor aluminium alloy follows the Langmuir adsorption isotherm. This shows that the corrosion rate of aluminium alloy with silicon carbide in NaCI environment decreased significantly with addition of the inhibitor.展开更多
It is well-known that the propagation phenomena of nonlocal dispersal equations have been extensively studied,and the known results on the interface dynamics of this equation are under the compactly supported initial ...It is well-known that the propagation phenomena of nonlocal dispersal equations have been extensively studied,and the known results on the interface dynamics of this equation are under the compactly supported initial value.Moreover,there was no explicit formula regarding the interface due to the peculiarity of nonlocal dispersal operators.Anatural question is whether it is possible to provide a precise characterization of the interface with respect to small parameter for the general initial values(including exponentially bounded and unbounded).This paper is concerned with the interface dynamics of the nonlocal dispersal equation with scaling parameter.For the exponentially bounded initial value,by choosing the hyperbolic scaling,we show that at a very small time,the interface is confined within a generated layer whose thickness is at most O(√ɛ|ln ɛ|),,and subsequently,the interface propagates at a linear speed determined by the decay rate of initial value.For a class of exponentially unbounded initial value,by introducing the nonlinear scaling based on the decay of initial value,we deduce the corresponding Hamilton-Jacobi equation and describe precisely the propagation of the interface,which provides a superlinear speed of the interface.The investigation of the interface dynamics under different scaling reflects multiplex propagation modes in spatial dynamics and provides a new perspective on the wave propagation in nonlocal dispersal equations.展开更多
In this paper,we consider the plasma-vacuum interface problem in a cylindrical tube region impressed by a special background magnetic field.The interior region is occupied with plasma,which is governed by the incompre...In this paper,we consider the plasma-vacuum interface problem in a cylindrical tube region impressed by a special background magnetic field.The interior region is occupied with plasma,which is governed by the incompressible inviscid and resistive MHD system without damping term.The exterior vacuum region is governed by the so-called the“pre-Maxwell equations”.And on the free interface,additionally,the effect of surface tension is taken into account.The original region can be transformed into a horizontally periodic slab through the cylindrical coordinate transformation,which will be impressed by a uniform nonhorizontal magnetic field.Appending with the appropriate physical boundary conditions,the global well-posedness of the problem is established by the energy method.展开更多
Intrinsic hydrogenated amorphous silicon（a-Si：H） film is deposited on n-type crystalline silicon（c-Si） wafer by hotwire chemical vapor deposition（HWCVD） to analyze the amorphous/crystalline heterointerface pass...Intrinsic hydrogenated amorphous silicon（a-Si：H） film is deposited on n-type crystalline silicon（c-Si） wafer by hotwire chemical vapor deposition（HWCVD） to analyze the amorphous/crystalline heterointerface passivation properties.The minority carrier lifetime of symmetric heterostructure is measured by using Sinton Consulting WCT-120 lifetime tester system,and a simple method of determining the interface state density（D_（it）） from lifetime measurement is proposed.The interface state density（D_（it）） measurement is also performed by using deep-level transient spectroscopy（DLTS） to prove the validity of the simple method.The microstructures and hydrogen bonding configurations of a-Si：H films with different hydrogen dilutions are investigated by using spectroscopic ellipsometry（SE） and Fourier transform infrared spectroscopy（FTIR） respectively.Lower values of interface state density（D_（it）） are obtained by using a-Si：H film with more uniform,compact microstructures and fewer bulk defects on crystalline silicon deposited by HWCVD.展开更多
基金supported by the National Key R&D Program of China (No. 2018YFA0707300)the National Natural Science Foundation of China (No. 52374376)the Introduction Plan for High end Foreign Experts, China (No. G2023105001L)。
文摘Titanium plates with a Ti−O solid solution surface-hardened layer were cold roll-bonded with 304 stainless steel plates with high work hardening rates.The evolution and mechanisms affecting the interfacial bonding strength in titanium/stainless steel laminated composites were investigated.Results indicate that the hardened layer reduces the interfacial bonding strength from over 261 MPa to less than 204 MPa.During the cold roll-bonding process,the hardened layer fractures,leading to the formation of multi-scale cracks that are difficult for the stainless steel to fill.This not only hinders the development of an interlocking interface but also leads to the presence of numerous microcracks and hardened blocks along the nearly straight interface,consequently weakening the interfacial bonding strength.In metals with high work hardening rates,the conventional approach of enhancing interface interlocking and improving interfacial bonding strength by using a surface-hardened layer becomes less effective.
基金Project(50974036)supported by the National Natural Science Foundation of China
文摘The adsorption isotherm of sodium polyacrylate on dicalcium silicate（2CaO-SiO2） in sodium aluminate solution at 80 ℃ was studied.The type of surface adsorption of sodium polyacrylate is saturated adsorption,and the adsorption behavior belongs to L-type,according with the monolayer adsorption model of Langmuir equation.The surface coverage of sodium polyacrylate is 1.06 mol/μm2.The relation curve between the surface pressure and the molecular area of adsorption film was obtained by Gibbs formula.The variation of interfacial energy caused by adsorption as well as the relationship between the relation curve and the type of adsorption was discussed.
基金the National Key R&D Plan of the Ministry of Science and Technology of China(2022YFE0122400)National Natural Science Foundation of China(52002238,22102207)+1 种基金Science and Technology Commission of Shanghai Municipality(22ZR1423800,21ZR1465200,23ZR1423600)Shanghai Municipal Education Commission and the NSRF via the Program Management Unit for Human Resources&Institutional Development,Research and Innovation(B49G680115).
文摘Silicon stands as a key anode material in lithium-ion battery ascribing to its high energy density.Nevertheless,the poor rate performance and limited cycling life remain unresolved through conventional approaches that involve carbon composites or nanostructures,primarily due to the un-controllable effects arising from the substantial formation of a solid electrolyte interphase(SEI)during the cycling.Here,an ultra-thin and homogeneous Ti doping alumina oxide catalytic interface is meticulously applied on the porous Si through a synergistic etching and hydrolysis process.This defect-rich oxide interface promotes a selective adsorption of fluoroethylene carbonate,leading to a catalytic reaction that can be aptly described as“molecular concentration-in situ conversion”.The resultant inorganic-rich SEI layer is electrochemical stable and favors ion-transport,particularly at high-rate cycling and high temperature.The robustly shielded porous Si,with a large surface area,achieves a high initial Coulombic efficiency of 84.7%and delivers exceptional high-rate performance at 25 A g^(−1)(692 mAh g^(−1))and a high Coulombic efficiency of 99.7%over 1000 cycles.The robust SEI constructed through a precious catalytic layer promises significant advantages for the fast development of silicon-based anode in fast-charging batteries.
文摘This paper presents an exact solution for the transverse interface crack in the plane strain case. The crack is perpendicular to the interface and in one material. The exact complex stress functions are first obtained with some unknown constants. The satisfactions of all boundary conditions are then checked, the condition at infinity is considered and the unknown constants are determined. Further study may focus on the case with different shear moduli and the influence of the large deformation.
文摘For the diffusion-controlled adsorption, the expression of dynamic surface adsorption P（t） was ob- tained by solving the diffusion equation. Two cases, i.e. the short and long time limits, were mainly discussed in this paper. From the measured dynamic surface tension of aqueous surfactant sodium dodecyl sulfate （SDS） solutions at 25 ℃, the adsorption kinetics of SDS at air/solution interface was studied. It was proved that for both of the short and long time limits, the adsorption process of SDS was controlled by diffusion.
基金Project(02-09-01) supported by Panzhihua Iron and Steel Corporation,China
文摘Membrane/solution interface consists of a neutral concentration polai layer(CPL) and a charge layer(CL) under external electrical field, and the neutral CPL can be neglected under high frequency AC electrical field. The relationship of CL thickness e with electrolyte concentration C and fixed ion exchange sites density σ in membrane surface layer can be expressed as e
文摘In this paper a pH microprobe technique was developed to measure in-situ the pH value at the electrode/solution interface. Iridium oxide was used as a pH sensitive material with good response behavior in the measured solutions. The experimental results indicated that the interfacial pH increased with the applied potential, first jumped to a maximum, then slowly decreased at the controlled potential during the electrodeposition process of functional ceramics.
基金Supported by the National Natural Science Foundation of China(Grant No.11071266)National Natural Science Foundation of China,Tian Yuan Special Foundation(Grant No.11226181)+1 种基金Scientific Research Fund of Sichuan Provincial Education Department(Grant No.13ZA0010)the Natural Science Foundation Project of China West Normal University(Grant No.12B024)
文摘In this paper, we first find finite travelling-wave solutions, and then investigate the short time development of interfaces for non-Newtonian diffusion equations with strong absorption. We show that the initial behavior of the interface depends on the concentration of the mass of u（x,0） near x=0. More precisely, we find a critical value of the concentration, which separates the heating front of interfaces from the cooling front of them.
基金This paper was suported by the National Natural Science Foundation of China.
文摘In situ x-ray diffraction electrochemical method is used to study the activation of silver electrode in KCl solution and UPD lead on silver electrode surface. We found that the activation makes the silver crystal thicker in (111), and the arrangement of water molecules on the silver electrode surface with UPD lead is partially ordered.
基金supported by the National Natural Science Foundation of China(No.21904143).
文摘Single-entity collisional electrochemistry(SECE)is a branch of single-entity electrochemistry.It can directly characterize entities/particles with single particle resolution through random collisions between particles and electrodes in a solution,and obtain rich physicochemical information,thus becoming one of the frontiers of electroanalytical chemistry in the past two decades.Interestingly,the(micro/nanoscale)sensing electrodes have evolved from a polarizable liquid/liquid(mercury/liquid)interface to a solid/liquid interface and then to a liquid/liquid interface(i.e.,an interface between twoimmiscible electrolyte solutions,ITIES),as if they have completed a cycle(but in fact they have not).ITIES has become the latest sensing electrode in the booming SECE due to its polarizability(up to 1.1 V at the water/a,a,a-trifluorotoluene interface)and high reproducibility.The four measurement modes(direct electrolysis,mediated electrolysis,current blockade,and charge displacement)developed in the realm of SECE at solid/liquid interfaces have also been fully realized at the miniature ITIES.This article will discuss these four modes at the ITIES from the perspectives of basic concepts,operating mechanisms,and latest developments(e.g.,discovery of ionosomes,blockade effect of Faradaic ion transfer,etc.),and look forward to the future development and direction of this emerging field.
文摘In this paper, the eigen function expansions of displacements and stresses of bi-metal laminates with interface cracks are obtained. Furthermore, the stress intensity factors are determined by the variational method to satisfy the boundary conditions and there are only line integrals in the variational equations due to the previous satisfaction of all basic equations. The computations show that this method of solution has the advantages of rapid convergency and time-saving. The results obtained by this method for homogeneous material agree with the known ones very well.
基金Projects (50941020, 10902086, 50875217, 20903075) supported by the National Natural Science Foundation of ChinaProjects (SJ08-ZT05, SJ08-B14) supported by the Natural Science Foundation of Shaanxi Province, ChinaProject (CX200905) supported by the Doctorate Foundation of Northwestern Polytechnical University, China
文摘Based on the microscopic phase-field model, ordered domain interfaces formed between D022 （Ni3V） phases along [001] direction in Ni75AlxV25-x alloys were simulated, and the effects of atomic structure on the migration characteristic and solute segregation of interfaces were studied. It is found that the migration ability is related to the atomic structure of interfaces, and three kinds of interfaces can migrate except the interface （001）//（002） which has the characteristic of L12 （Ni3Al） structure. V atoms jump to the nearest neighbor site and substitute for Ni, and vice versa. Because of the site selectivity behaviors of jumping atoms, the number of jumping atoms during the migration is the least and the jumping distance of atoms is the shortest among all possible modes, and the atomic structures of interfaces are unchanged before and after the migration. The preferences and degree of segregation or depletion of alloy elements are also related to the atomic structure of interface.
文摘Currently, a conventional two-step method has been used to generate black silicon （BS） surfaces on silicon substrates for solar cell manufacturing. However, the performances of the solar cell made with such surface generation method are poor, because of the high surface recombination caused by deep etching in the conventional surface generation method for BS. In this work, a modified wet chemical etching solution with additives was developed. A homogeneous BS layer with random porous structure was obtained from the modified solution in only one step at room temperature. The BS layer had low reflectivity and shallow etching depth. The additive in the etch solution performs the function of pH-modulation. After 16-min etching, the etching depth in the samples was approximately 200 nm, and the spectrum-weighted-reflectivity in the range from 300 nm to 1200 nm was below 5%. BS solar cells were fabricated in the production line. The decreased etching depth can improve the electrical performance of solar cells because of the decrease in surface recombination. An efficiency of 15.63% for the modified etching BS solar cells was achieved on a large area, p- type single crystalline silicon substrate with a 624.32-mV open circuit voltage and a 77.88% fill factor.
文摘By inserting a thin highly doped crystalline silicon layer between the base region and amorphous silicon layer in an interdigitated back-contact （IBC） silicon solar cell, a new passivation layer is investigated. The passivation layer performance is characterized by numerical simulations. Moreover, the dependence of the output parameters of the solar cell on the additional layer parameters （doping concentration and thickness） is studied. By optimizing the additional passivation layer in terms of doping concentration and thickness, the power conversion efficiency could be improved by a factor of 2.5%, open circuit voltage is increased by 30 mV and the fill factor of the solar cell by 7.4%. The performance enhancement is achieved due to the decrease of recombination rate, a decrease in solar cell resistivity and improvement of field effect passivation at heterojunction interface. The above-mentioned results are compared with reported results of the same conventional interdigitated back-contact silicon solar cell structure. Furthermore, the effect of a-Si：H/c-Si interface defect density on IBC silicon solar cell parameters with a new passivation layer is studied. The additional passivation layer also reduces the sensitivity of output parameter of solar cell to interface defect density.
基金supported by the National Natural Science Foundation of China(Nos.61665012,61575168 and 11504313)the International Science Cooperation Project of the Ministry of Education of the People’s Republic of China(No.2016–2196)
文摘One problem associated with microcavity devices is the significant difference between the reflection spectra of fabricated porous silicon microcavity(PSM) devices and those obtained by theoretical calculation of ideal microcavity devices.To address this problem, studies were carried out to determine the effects of the refractive index dispersion, the absorption of the porous silicon layer and the fluctuation of the dielectric interface on the reflection spectra of PSM devices.The results are in good agreement with those obtained experimentally from the fabricated PSM devices, which provides a theoretical basis for the design of PSM sensors.
基金Supported by the National Research Foundation for the Department of Chemical,Metallurgical and Materials Engineering,Tshwane University of Technology,Pretoria with respect to equipment and funding
文摘The present work focused on corrosion inhibition of AA6063 type Al-Mg-Si alloy in sodium chloride （NaCI） solution with a silicon carbide inhibitor, using the potentiodynamic electrochemical method. The aluminium alloy surface morphology was examined, in the as-received and as-corroded in the un-inhibited state, with scanning electron microscopy equipped with energy dispersive spectroscopy （SEM-EDS）. The results obtained via linear polarization indicated a high corrosion potential for the unprotected as-received alloy. Equally, inhibition efficiency as high as 98.82% at 10.0 g/v silicon carbide addition was obtained with increased polarization resistance fRy）, while the current density reduced significantly for inhibited samples compared to the un-inhibited aluminium alloy. The adsorption mechanism of the inhibitor aluminium alloy follows the Langmuir adsorption isotherm. This shows that the corrosion rate of aluminium alloy with silicon carbide in NaCI environment decreased significantly with addition of the inhibitor.
基金partially supported by the NSF of China(12271226)partially supported by the NSF of China(12201434)+4 种基金the NSF of Gansu Province of China(21JR7RA537)the NSF of Gansu Province of China(21JR7RA535)the Fundamental Research Funds for the Central Universities(lzujbky-2021-kb15)partially supported by the NSF of China(12371170)the R&D Program of Beijing Municipal Education Commission(KM202310028017)。
文摘It is well-known that the propagation phenomena of nonlocal dispersal equations have been extensively studied,and the known results on the interface dynamics of this equation are under the compactly supported initial value.Moreover,there was no explicit formula regarding the interface due to the peculiarity of nonlocal dispersal operators.Anatural question is whether it is possible to provide a precise characterization of the interface with respect to small parameter for the general initial values(including exponentially bounded and unbounded).This paper is concerned with the interface dynamics of the nonlocal dispersal equation with scaling parameter.For the exponentially bounded initial value,by choosing the hyperbolic scaling,we show that at a very small time,the interface is confined within a generated layer whose thickness is at most O(√ɛ|ln ɛ|),,and subsequently,the interface propagates at a linear speed determined by the decay rate of initial value.For a class of exponentially unbounded initial value,by introducing the nonlinear scaling based on the decay of initial value,we deduce the corresponding Hamilton-Jacobi equation and describe precisely the propagation of the interface,which provides a superlinear speed of the interface.The investigation of the interface dynamics under different scaling reflects multiplex propagation modes in spatial dynamics and provides a new perspective on the wave propagation in nonlocal dispersal equations.
基金supported by the NSFC(11571177)the National Key Research and Development Program of China(2020YFA0713803).
文摘In this paper,we consider the plasma-vacuum interface problem in a cylindrical tube region impressed by a special background magnetic field.The interior region is occupied with plasma,which is governed by the incompressible inviscid and resistive MHD system without damping term.The exterior vacuum region is governed by the so-called the“pre-Maxwell equations”.And on the free interface,additionally,the effect of surface tension is taken into account.The original region can be transformed into a horizontally periodic slab through the cylindrical coordinate transformation,which will be impressed by a uniform nonhorizontal magnetic field.Appending with the appropriate physical boundary conditions,the global well-posedness of the problem is established by the energy method.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51361022 and 61574072)the Postdoctoral Science Foundation of Jiangxi Province,China(Grant No.2015KY12)
文摘Intrinsic hydrogenated amorphous silicon（a-Si：H） film is deposited on n-type crystalline silicon（c-Si） wafer by hotwire chemical vapor deposition（HWCVD） to analyze the amorphous/crystalline heterointerface passivation properties.The minority carrier lifetime of symmetric heterostructure is measured by using Sinton Consulting WCT-120 lifetime tester system,and a simple method of determining the interface state density（D_（it）） from lifetime measurement is proposed.The interface state density（D_（it）） measurement is also performed by using deep-level transient spectroscopy（DLTS） to prove the validity of the simple method.The microstructures and hydrogen bonding configurations of a-Si：H films with different hydrogen dilutions are investigated by using spectroscopic ellipsometry（SE） and Fourier transform infrared spectroscopy（FTIR） respectively.Lower values of interface state density（D_（it）） are obtained by using a-Si：H film with more uniform,compact microstructures and fewer bulk defects on crystalline silicon deposited by HWCVD.
