A new type of nickel-based single-crystal superalloy was subjected to creep performance test,microstructure observation,and composition analysis under the condition of 1100℃/140 MPa.The variation characteristics of t...A new type of nickel-based single-crystal superalloy was subjected to creep performance test,microstructure observation,and composition analysis under the condition of 1100℃/140 MPa.The variation characteristics of the creep rate during the creep fracture process and the microstructure evolution before and after creep were investigated,thereby revealing the creep fracture mechanism of the new nickel-based single-crystal superalloy.The results indicate that the creep life of the alloy is 104.5 h,and the strain can reach 33.58%.The creep rate decreases first,then increases,and finally tends to be stable until fracture.At the initial stage of creep,the creep rate decreases first,then rises and finally decreases again with time.Furthermore,the creep fracture microstructure is composed of dimples and tearing edges without obvious slip planes.Oxides and recrystallized structures exist inside the fracture surface,and the voids inside the fracture are elongated and perpendicular to the stress axis,showing a fracture mechanism of microcrack accumulation.展开更多
The as-deposited coating-substrate microstructure has been identified to substantially influence the high-cycle fatigue(HCF)behavior of Ni-based single-crystal(SX)superalloys at 900℃,but the impact of degraded micros...The as-deposited coating-substrate microstructure has been identified to substantially influence the high-cycle fatigue(HCF)behavior of Ni-based single-crystal(SX)superalloys at 900℃,but the impact of degraded microstructure on the HCF behavior remains unclear.In this work,a PtAl-coated third-generation SX superalloy with sheet specimen was thermal-exposed at 1100℃ with different durations and then subjected to HCF tests at 900℃.The influence of microstructural degradation on the HCF life and crack initiation were clarified by analyzing the development of microcracks and coating-substrate microstructure.Notably,the HCF life of the thermal-exposed coated alloy increased abnormally,which was attributed to the transformation of the fatigue crack initiation site from surface mi-crocracks to internal micropores compared to the as-deposited coated alloy.Although the nucleation and growth of surface microcracks occurred along the grain boundaries in the coating and the interdiffusion zone(IDZ)for both the as-deposited and the thermal-exposed coated alloys,remarkable differences of the microcrack growth into the substrate adjacent to the IDZ were observed,changing the crack initiation site.Specifically,the surface microcracks grew into the substrate through the cracking of the non-protective oxide layers in the as-deposited coated alloy.In comparison,the hinderance of the surface microcracks growth was found in the thermal-exposed coated al-loy,due to the formation of a protective Al_(2)O_(3) layer within the microcrack and theγ′rafting in the substrate close to the IDZ.This study will aid in improving the HCF life prediction model for the coated SX superalloys.展开更多
Nickel-based single-crystal(SX)superalloys are the key metallic materials of aeroengines.However,thermomechanical deformation always occurs during the directional solidification of SX superalloys,negatively influencin...Nickel-based single-crystal(SX)superalloys are the key metallic materials of aeroengines.However,thermomechanical deformation always occurs during the directional solidification of SX superalloys,negatively influencing the SX structure.Casting deformation is simulated in most of the previous studies,whereas the direct simulation of dendritic thermomechanical deformation has been largely ignored,resulting in a lack of comprehensive understanding of this process.In this study,we systematically investigate dendritic thermomechanical deformation with a model coupled with dendrite growth,fluid flow,and thermomechanical deformation behavior.Results reveal that the dendritic thermomechanical deformation-induced dendrite bending is not randomly distributed but is mainly concentrated on the casting surface.The dendritic thermal stress increases as dendrite grows and accumulates after dendrite bridging.Transverse thermal contraction mainly occurs at the edge of casting in the corner,and axial thermal contraction is larger than transverse contraction.The high-stress region of the primary dendrite trunk is mainly distributed below the dendrite bridging near the solidified part,and the stress along the transverse direction reaches its maximum value on the casting surface.Stress concentrated on the casting surface is mainly attributed to variations in transverse temperature gradients caused by heat dissipation on the lateral mold wall,and inconsistent constraints in the lateral mold walls.展开更多
Exploring the synthesis of novel structures is crucial for the development of functional materials.In this context,a novel and intriguing 3d-5p heterometallic cluster-substituted polyoxotungstate material,H_(29)Na_(9)...Exploring the synthesis of novel structures is crucial for the development of functional materials.In this context,a novel and intriguing 3d-5p heterometallic cluster-substituted polyoxotungstate material,H_(29)Na_(9)(H_(2)O)_(21){Ca(H_(2)O)_(2)@Sb_(12)O_(18)[Ni_(2)(OH)(A-α-Si W_(10)O_(37))]_(3)}_(2)·40H_(2)O(1),was constructed using Keggintype polyoxotungstate A-α-Si W_(10)O_(37),along with Ni and Sb elements.The structure features a Tdsymmetric Sb_(12)O_(18)({Sb_(12)})cage that encapsulates an 8-coordinate Ca^(2+)ion at its face.Additionally,the{Sb_(12)}cage forms an 18-nuclear 3d-5p heterometallic cluster by connecting with three di-nuclear nickel clusters through shared oxygen atoms.Electrochemical impedance spectra studies reveal that the single crystal of 1 achieves a proton conductivity of 1.11×10^(-1)S/cm along the[110]direction and 1.04×10^(-1)S/cm along the[100]direction at 85℃ and 98%relative humidity(RH).Furthermore,the powder form of 1 exhibits a proton conductivity of 3.00×10^(-2)S/cm.These findings suggest that compound 1 holds promise as a practical proton conducting material.展开更多
Conventional polycrystalline LiMn_(2)O_(4)(PC-LMO)suffers from poor Li^(+)diffusion rates and structural instability,negatively affecting its electrochemical performance.Here,we design a single-crystal LMO cathode mat...Conventional polycrystalline LiMn_(2)O_(4)(PC-LMO)suffers from poor Li^(+)diffusion rates and structural instability,negatively affecting its electrochemical performance.Here,we design a single-crystal LMO cathode material using BaO flux(SC-LMOB)to address these issues.The BaO flux enables the fabrication of brick-like single-crystal particles,enhancing Li^(+)diffusion by shortening the diffusion path and increasing the unit cell volume.This process also reduces the specific surface area and stabilizes the crystal structure,effectively mitigating Mn dissolution and polarization.As a result,SC-LMOB exhibits ultra-high rate performance and superior structural stability,retaining 88.8%of its capacity at a 20 C discharge rate and achieving capacity retentions of 85.3%and 86.0%after 500 and 300 cycles at 1 C at room and elevated temperatures,respectively.This structural design offers a low-cost,scalable approach for fabricating single-crystal cathode materials with excellent performance.展开更多
Covalent organic frameworks(COFs)have demonstrated great potential in chromatographic separation because of unique structure and superior performance.Herein,single-crystal three-dimensional(3D)COFs with regular morpho...Covalent organic frameworks(COFs)have demonstrated great potential in chromatographic separation because of unique structure and superior performance.Herein,single-crystal three-dimensional(3D)COFs with regular morphology,good monodispersity and high specific surface area,were used as a stationary phase for high-performance liquid chromatography(HPLC).The single-crystal 3D COFs packed column not only exhibits high efficiency in separating hydrophobic molecules involving substituted benzenes,halogenated benzenes,halogenated nitrobenzenes,aromatic amines,aromatic hydrocarbons(PAHs)and phthalate esters(PAEs),but also achieves baseline separation of acenaphthene and acenaphthylene with similar physical and chemical properties as well as environmental pollutants,which cannot be quickly separated on commercial C18 column and a polycrystalline 3D COFs packed column.Especially,the column efficiency of 17303-24255 plates/m was obtained for PAEs,and the resolution values for acenaphthene and acenaphthylene,and carbamazepine(CBZ)and carbamazepine-10,11-epoxide(CBZEP)were 1.7and 2.2,respectively.This successful application not only confirmed the great potential of the singlecrystal 3D COFs in HPLC separation of the organic molecules,but also facilitates the application of COFs in separation science.展开更多
Quantifying the residual stress at micron-scale is crucial for comprehending the trans-and inter-granular deformation mechanisms and the influence of heat treatment,but remains technically challenging.This study utili...Quantifying the residual stress at micron-scale is crucial for comprehending the trans-and inter-granular deformation mechanisms and the influence of heat treatment,but remains technically challenging.This study utilized focused ion beam and digital image correlation(FIB-DIC)techniques to assess residual stress within the dendrite stem and arm of nickel-based single-crystal superalloys.The influence of hot isostatic pressing(HIP)on the microstructure and residual stress was also elucidated.Our results revealed that the residual stresses in the dendrite stem and arm regions manifest as tensile stress along the x-axis and compressive stress along the y-axis,with a range of−720 MPa to 680 MPa.HIP treatment effectively improved microstructure and regulated residual stress in nickel-based single-crystal superalloys,leading to a rapid reduction in residual stress levels.The present study lays a solid theoretical groundwork for optimizing processing strategies to regulate residual stress and enhance mechanical properties in next-generation single-crystal superalloys.展开更多
Thermal barrier coating(TBC)is crucial for the performance of turbine blades at high temperatures;however,it degrades the microstructure of single-crystal superalloy(SX),thereby reducing creep life.Despite this,the de...Thermal barrier coating(TBC)is crucial for the performance of turbine blades at high temperatures;however,it degrades the microstructure of single-crystal superalloy(SX),thereby reducing creep life.Despite this,the degradation mechanisms associated with the complex multi-layer damage and inter-layer diffusion behavior for TBC/SX systems have not yet been fully elucidated.In this study,using integrated experimental efforts and multiscale characterization techniques,the creep degradation mechanisms of TBC/SX systems at 900℃/500 MPa,980℃/300 MPa,and 1050℃/160 MPa are systematically investigated.Results demonstrate that the creep degradation from TBC intensifies with increasing temperature(T)and stress(σ)ratio(T/σ),exhibiting significant dependency on these two factors,and primarily reduces lifespan of the steady-state stage,with minimal effects on the accelerating stage.During creep deformation,the cracking behavior caused by thermally grown oxide(TGO)beneath the top coat(TC)layer,voids resulting from internal oxidation and interdiffusion in the bond coat(BC)layer,and the recrystallization growth driven by the sandblasting process in the secondary reaction zone(SRZ)are temperature-sensitive damages.In contrast,the initiation and propagation of cracks associated with the topologically close-packed(TCP)phases in the SRZ exhibit pronounced stress sensitivity.Furthermore,the formation of the substrate diffusion zone(SDZ)and the decomposition ofγ/γ′interfacial dislocation networks driven by the Cr-Ru diffusion,as well as the increased stacking fault energy in theγ′phase due to Co loss,are responsible for the acceleration of steady-state creep rate at 1050℃/160 MPa.This work provides a comprehensive and in-depth understanding of the degradation mechanisms under thermal-mechanical coupling in TBC/SX systems,offering new insights into targeted design optimization for multilayered coatings.展开更多
Based on the high-purity single-crystal tungsten nanowire firstly prepared by the metal-catalyzed vapor-phase reaction method, molecular dynamics method was used to calculate tensile stress-strain curves and simulate ...Based on the high-purity single-crystal tungsten nanowire firstly prepared by the metal-catalyzed vapor-phase reaction method, molecular dynamics method was used to calculate tensile stress-strain curves and simulate microscopic deformation structures of the single-crystal tungsten nanowires with different crystal orientations of 〈100〉, 〈110〉and 〈111〉, in order to reveal the effect of crystal orientation on their tensile mechanical properties and failure mechanisms. Research results show that all of the stress-strain curves are classified into four stages： elastic stage, damage stage, yielding stage and failure stage, where 〈100〉orientation has a special hardening stage after yielding and two descending stages. The crystal orientation has little effect on elastic modulus but great effect on tensile strength, yielding strength and ductility, depending on different atomic surface energies and principal sliding planes. The calculated values of elastic modulus are in good agreement with the tested values of elastic modulus.展开更多
The dynamic recrystallization behavior of single-crystal（SC） superalloy SR.R99 at low strain rate was investigated by high-temperature creep testing.The results show that dynamic recrystallization may take place aft...The dynamic recrystallization behavior of single-crystal（SC） superalloy SR.R99 at low strain rate was investigated by high-temperature creep testing.The results show that dynamic recrystallization may take place after the uncoated samples have been creep-tested in air at high temperature and low stress for a long time.Both the threshold temperature and strain for the dynamic recrystallization of SC superalloy SRR99 at low strain rate are lower than those for the static recrystallization.Dynamically recrystallized grains with the depth less than 15 μm are only located in the surface γ＇-free layers,and the recrystallized grains are well-developed grains without columnar y＇precipitates within them.The dynamic recrystallization behavior of SC superalloy SRR99 at low strain rate is mainly related to high-temperature oxidation.Suitable protective coating can effectively prevent the dynamic recrystallization of SC superalloy components in service.In addition,the dynamic recrystallization behavior of SC superalloy SRR99 at high strain rate was also studied by high-temperature compression testing.At high strain rate,a higher temperature and larger strain are needed for the occurrence of dynamic recrystallization than at low strain rate,and the recrystallized grains have cellular structures with an amount of columnar γ＇ precipitates within them.展开更多
Single-crystal Ni-rich cathode material LiNi0.88Co0.09Al0.03O2(SC) was synthesized by a high-temperature solid-state calcination method. Physicochemical properties of primary and delithiated SC samples were investigat...Single-crystal Ni-rich cathode material LiNi0.88Co0.09Al0.03O2(SC) was synthesized by a high-temperature solid-state calcination method. Physicochemical properties of primary and delithiated SC samples were investigated by X-ray diffractometry, X-ray photoelectron spectroscopy, and transmission electron microscopy. Electrochemical performance was characterized by long-term cycling, cyclic voltammetry, and in-situ impedance spectroscopy. The results indicated that high temperature rendered layered oxides to lose lithium/oxygen in the interior and exterior, and induced cationic disordering. Besides, the solid-phase synthesis process promoted phase transformation for electrode materials, causing the coexisting multi-phase in a single particle. High temperature can foster the growth of single particles, but it caused unstable structure of layered phase.展开更多
MCrAlY(M=Ni and/or Co)overlay coating is widely used as a protective coating against high temperature oxidation and corrosion.However,due to its big difference in chemical composition with the underlying superalloy,el...MCrAlY(M=Ni and/or Co)overlay coating is widely used as a protective coating against high temperature oxidation and corrosion.However,due to its big difference in chemical composition with the underlying superalloy,elements interdiffusion occurs inevitably.One of the direct results is the formation of interdiffusion zone(IDZ)and secondary reaction zone(SRZ)with a high density of fine topological closed-packed phases(TCPs),weakening dramatically the mechanical properties of the alloy substrate.It is by now the main problem of modern high-temperature metallic coatings,but there are still hardly any reports studying the formation,growth and transformation of IDZ and SRZ in deep,as well as the precipitation of TCPs.In this work,a typical NiCrAlY coating is deposited by arc ion plating on a single-crystal superalloy N5.Elements interdiffusion between them and its relationship on microstructure were clarified.Cr rather than Al from the coating diffuses into the alloy at high temperatures and segregates immediately beneath their interface,contributing largely to the formation of IDZ.Simultaneously,diffusion of Ni from the deep alloy to IDZ leads to the formation and continuous expansion of SRZ.展开更多
Chemical vapor deposition(CVD)-grown diamond films have been developed as irradiation-resistant materials to replace or upgrade current detectors for use in extreme radiation environments. However, their sensitivity i...Chemical vapor deposition(CVD)-grown diamond films have been developed as irradiation-resistant materials to replace or upgrade current detectors for use in extreme radiation environments. However, their sensitivity in practical applications has been inhibited by space charge stability issues caused by defects and impurities in pure diamond crystal materials. In this study, two high-quality CVD-grown single-crystal diamond(SCD) detectors with low content of nitrogen impurities were fabricated and characterized. The intrinsic properties of the SCD samples were characterized using Raman spectroscopy, stereomicroscopy, and X-ray diffraction with the rocking curve mode, cathode luminescence(CL), and infrared and ultraviolet-visible-near infrared spectroscopies. After packaging the detectors, the dark current and energy resolution under α particle irradiation were investigated. Dark currents of less than 5 pA at 100 V were obtained after annealing the electrodes, which is comparable with the optimal value previously reported. The detector that uses a diamond film with higher nitrogen content showed poor energy resolution, whereas the detector with more dislocations showed poor charge collection efficiency(CCE). This demonstrates that the nitrogen content in diamond has a significant effect on the energy resolution of detectors, while the dislocations in diamond largely contribute to the poor CCE of detectors.展开更多
The influence of orientation on the stress rupture behaviors of a 3 rd-generation nickel-based single-crystal superalloy was investigated at 1100℃/150 MPa.It is found that the stress rupture anisotropy is shown at 1...The influence of orientation on the stress rupture behaviors of a 3 rd-generation nickel-based single-crystal superalloy was investigated at 1100℃/150 MPa.It is found that the stress rupture anisotropy is shown at 1100℃,but not so obvious compared with that at intermediate temperatures.The [001] specimens display the longest rupture life,[111] specimens show the shortest rupture life,and [011] specimens exhibit the intermediate life.Detailed observations show that the final fracture is caused by crack initiation and propagation,and the anisotropy of three oriented specimens is related to the fracture modes,γ/γ’ microstructures,interfacial dislocation networks and cutting mechanisms in y’ phase.For [001] specimens,N-type rafted structures are formed which can well hinder the slip and climb of dislocations.Besides,the regular interfacial dislocation networks can prevent dislocations from cutting into y’ phase,leading to the improvement of the creep resistance.For [011] specimens,±45°rafted structures and irregular networks result in less strain hardening.For [111] specimens,a large number of crack propagation paths and inhomogeneous deformations caused by irregular rafted structures deteriorate the property and result in the shortest life.Furthermore,a[100] superdislocations with low mobility are widely formed in[001] and [011] specimens which suggests the low creep strain rate during steady creep stage,whereas superdislocations in[111] specimens possess high mobility,which indicates the high strain rate and corresponding poor stress rupture property.展开更多
The isothermal oxidation behavior of a new Refree nickel-based single-crystal superalloy in air at 950 ℃ for 200 h was studied by scanning electron microscopy（SEM）with energy-dispersive spectroscopy（EDS）and X-ray...The isothermal oxidation behavior of a new Refree nickel-based single-crystal superalloy in air at 950 ℃ for 200 h was studied by scanning electron microscopy（SEM）with energy-dispersive spectroscopy（EDS）and X-ray diffraction（XRD）.The results indicate that oxidation kinetics obeys parabolic law approximately,and the mass gain increases rapidly during initial oxidation stage and then gradually slows down.The oxidation scales are composed of three layers：the outer layer mainly consists of NiO with a small amount of CoO;the intermediate layer is mainly composed of Cr_2O_3 with a small amount of spinel compounds such as CrTaO_4,NiCr_2O_4,CoCrAl_2O_4,CoAl_2O_4,and NiAl_2O_4;and the inner layer is composed of Al_2O_3.Inner Al_2O_3 layer suppresses the diffusion of elements between oxygen and alloy elements,slows down the alloy oxidation speed,and also suppresses the growth of the oxide scale and reduces the oxidation rate,which is agreeable with the oxidation kinetics.展开更多
Single-crystal LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(SC-811),which offers better cycle performance compared to the polycrystalline counterpart,has received great attention.We report herein the synthesis of SC-811 with a gra...Single-crystal LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(SC-811),which offers better cycle performance compared to the polycrystalline counterpart,has received great attention.We report herein the synthesis of SC-811 with a grain size of 2-4μm by washing and reheating method,which compares with conventional polycrystalline LiNi_(0.8)-Co_(0.1)Mn_(0.1)O_(2)(PC-811).The discharge capacity of SC-811 reaches 152.1 mAh·g^(-1)after 100 cycles(86.7%capacity retention)at 1.0 C,which is much better than that of PC-811(130.2 mAh·g^(-1),73.8%capacity retention).By using multiscale characterization,the results unveil that SC-811 can not only improve the reversibility of the H2-H3 phase transitions,suppress the generation of micro-cracks and phase transformations,but also mitigate the undesired side reactions between electrode and electrolyte.Besides,the Li-O bond of SC-811 is longer than that of PC-811,which is conducive to the de-intercalation of Li-ions,thereby enhancing the structural stability.This finding provides an impressive strategy to sustain structural stability and improve the cycling life of Ni-rich layered cathodes.展开更多
The influence of crystal orientations on the low-cycle fatigue(LCF) behavior of a 3Re-bearing Ni-based single-crystal superalloy at 980 °C has been investigated. It is found that the orientation dependence of the...The influence of crystal orientations on the low-cycle fatigue(LCF) behavior of a 3Re-bearing Ni-based single-crystal superalloy at 980 °C has been investigated. It is found that the orientation dependence of the fatigue life not only depends on the elastic modulus, but also the number of active slip planes and the plasticity of materials determine the LCF life,especially for the [011] and [111] specimens. The [011] and [111] specimens with better plasticity withstand relatively concentrated inelastic deformation caused by fewer active slip planes, compared to the [001] specimens resisting widespread deformation caused by a higher number of active slip planes. Additionally, fatigue fracture is also influenced by cyclic plastic deformation mechanisms of the alloy with crystal orientations, and the [001] specimens are plastically deformed by wave slip mechanism and fracture along the non-crystallographic plane, while the [011] and [111] specimens are plastically deformed by planar slip mechanism and fracture along the crystallographic planes. Moreover, casting pores,eutectics, inclusions and surface oxide layers not only initiate the crack, but also reduce the stress concentration around crack tips. Our results throw light upon the effect of inelastic strain on the LCF life and analyze the cyclic plastic deformation for the alloy with different orientations.展开更多
The effect of theγ+γtwo-phase structure on the oxidation behaviors of Ni-Al single-crystal alloys at 650℃was investigated by scanning electron microscopy,transmission electron microscopy,atomic force microscopy,X-r...The effect of theγ+γtwo-phase structure on the oxidation behaviors of Ni-Al single-crystal alloys at 650℃was investigated by scanning electron microscopy,transmission electron microscopy,atomic force microscopy,X-ray diffraction and Auger electron spectroscopy.In the initial oxidation stage,the oxidation behavior is primarily determined by the growth pattern of oxides in theγchannel.The outward convex NiO was formed in unprotected wideγchannels.And Ni-Al spinel oxide provides a great number of short-circuit paths,accelerating the inward diffusion of oxygen and outward diffusion of Ni.In the late stage of oxidation,the elongated internal oxide in the largeγphase contributes to the diffusion of oxygen along the oxide/metal interface.Consequently,the Ni-Al single-crystal alloy with wideγchannels and largeγprecipitates exhibited poor oxidation performance.展开更多
A successful repair of single-crystal components needs to avoid the stray grain formation and achieves continuous epitaxial growth of columnar dendrites in the repaired zone. In this study, the effect of substrate pre...A successful repair of single-crystal components needs to avoid the stray grain formation and achieves continuous epitaxial growth of columnar dendrites in the repaired zone. In this study, the effect of substrate preset temperature on crystal growth and microstructure formation in laser powder deposition of single-crystal superalloy was studied through an improved mathematical model and corresponding experimental approaches. The results indicated that the variation of substrate preset temperature between-30℃ and ＋210℃ changes the molten pool morphology little, but obviously affects the columnar-to-equiaxed transition conditions. The preheating of substrate facilitates the stray grain formation and enlarges the primary columnar dendrite arm spacing, while the situation for precooling of substrate is opposite. Under the specific processing conditions, the critical condition for continuous epitaxial growth is that the substrate preset temperature Tsub≤ ＋90℃. When the substrate preset temperature Tsubis below ＋90℃, the height ratio of melting depth to total height of the molten pool is larger than that of stray grain, ensuring that stray grains can be completely remelted and the continuous columnar dendrites during the multi-layer laser powder deposition process on（001） surface of single-crystal substrate can be achieved.展开更多
Epitaxial high-crystallization film semiconductor heterostructures has been proved to be an effective method to prepare single-crystal films for different functional devices in modern microelectronics,electro-optics,a...Epitaxial high-crystallization film semiconductor heterostructures has been proved to be an effective method to prepare single-crystal films for different functional devices in modern microelectronics,electro-optics,and optoelectronics.With superior semiconducting properties,halide perovskite materials are rising as building blocks for heterostructures.Here,the conformal vapor phase epitaxy of CsPbBr3 on PbS single-crystal films is realized to form the CsPbBr3/PbS heterostructures via a two-step vapor deposition process.The structural characterization reveals that PbS substrates and the epilayer CsPbBr3 have clear relationships:CsPbBr3(110)//PbS(100),CsPbBr3[001]//PbS[001]and CsPbBr3[001]//PbS[010].The absorption and photoluminescence(PL)characteristics of CsPbBr3/PbS heterostructures show the broadband light absorption and efficient photogenerated carrier transfer.Photodetectors based on the heterostructures show superior photoresponsivity of 15 A/W,high detectivity of 2.65×10^(11) Jones,fast response speed of 96 ms and obvious rectification behavior.Our study offers a convenient method for establishing the high-quality CsPbBr3/PbS single-crystal film heterostructures and providing an effective way for their application in optoelectronic devices.展开更多
基金China Postdoctoral Science Foundation General Project(2024M760034)Postdoctoral Research Programs of Anhui Province(2024A774)。
文摘A new type of nickel-based single-crystal superalloy was subjected to creep performance test,microstructure observation,and composition analysis under the condition of 1100℃/140 MPa.The variation characteristics of the creep rate during the creep fracture process and the microstructure evolution before and after creep were investigated,thereby revealing the creep fracture mechanism of the new nickel-based single-crystal superalloy.The results indicate that the creep life of the alloy is 104.5 h,and the strain can reach 33.58%.The creep rate decreases first,then increases,and finally tends to be stable until fracture.At the initial stage of creep,the creep rate decreases first,then rises and finally decreases again with time.Furthermore,the creep fracture microstructure is composed of dimples and tearing edges without obvious slip planes.Oxides and recrystallized structures exist inside the fracture surface,and the voids inside the fracture are elongated and perpendicular to the stress axis,showing a fracture mechanism of microcrack accumulation.
基金financially supported by National Key Research and Development Program of China(No.2022YFB 3708100)the Science Center for Gas Turbine Project,China(No.P2021-A-IV-002-001)+1 种基金the National Natural Science Foundation of China(Nos.52331005 and 52201100)the State Key Laboratory for Advanced Metals and Materials,China(No.2024-Z02).
文摘The as-deposited coating-substrate microstructure has been identified to substantially influence the high-cycle fatigue(HCF)behavior of Ni-based single-crystal(SX)superalloys at 900℃,but the impact of degraded microstructure on the HCF behavior remains unclear.In this work,a PtAl-coated third-generation SX superalloy with sheet specimen was thermal-exposed at 1100℃ with different durations and then subjected to HCF tests at 900℃.The influence of microstructural degradation on the HCF life and crack initiation were clarified by analyzing the development of microcracks and coating-substrate microstructure.Notably,the HCF life of the thermal-exposed coated alloy increased abnormally,which was attributed to the transformation of the fatigue crack initiation site from surface mi-crocracks to internal micropores compared to the as-deposited coated alloy.Although the nucleation and growth of surface microcracks occurred along the grain boundaries in the coating and the interdiffusion zone(IDZ)for both the as-deposited and the thermal-exposed coated alloys,remarkable differences of the microcrack growth into the substrate adjacent to the IDZ were observed,changing the crack initiation site.Specifically,the surface microcracks grew into the substrate through the cracking of the non-protective oxide layers in the as-deposited coated alloy.In comparison,the hinderance of the surface microcracks growth was found in the thermal-exposed coated al-loy,due to the formation of a protective Al_(2)O_(3) layer within the microcrack and theγ′rafting in the substrate close to the IDZ.This study will aid in improving the HCF life prediction model for the coated SX superalloys.
基金financially sponsored by the National Natural Science Foundation of China(Nos.U2441268 and 52304406)the Natural Science Foundation of Shanghai,China(No.23TS1401900)+2 种基金the Science Foundation of Aeronautics(PSSFA),China(No.2024Z053057002)the Science and Technology Cooperation Program of Shanghai Jiao Tong University in Inner Mongolia Autonomous Region-Action Plan of Shanghai Jiao Tong University for“Revitalizing Inner Mongolia through Science and Technology”,ChinaLuwei Yang would like to thank the financial support from the Chinese Scholarship Council(No.202306230337).
文摘Nickel-based single-crystal(SX)superalloys are the key metallic materials of aeroengines.However,thermomechanical deformation always occurs during the directional solidification of SX superalloys,negatively influencing the SX structure.Casting deformation is simulated in most of the previous studies,whereas the direct simulation of dendritic thermomechanical deformation has been largely ignored,resulting in a lack of comprehensive understanding of this process.In this study,we systematically investigate dendritic thermomechanical deformation with a model coupled with dendrite growth,fluid flow,and thermomechanical deformation behavior.Results reveal that the dendritic thermomechanical deformation-induced dendrite bending is not randomly distributed but is mainly concentrated on the casting surface.The dendritic thermal stress increases as dendrite grows and accumulates after dendrite bridging.Transverse thermal contraction mainly occurs at the edge of casting in the corner,and axial thermal contraction is larger than transverse contraction.The high-stress region of the primary dendrite trunk is mainly distributed below the dendrite bridging near the solidified part,and the stress along the transverse direction reaches its maximum value on the casting surface.Stress concentrated on the casting surface is mainly attributed to variations in transverse temperature gradients caused by heat dissipation on the lateral mold wall,and inconsistent constraints in the lateral mold walls.
基金the financial support from the National Natural Science Foundation of China(Nos.22109164 and 22371046)the Key Program of the Natural Science Foundation of Fujian Province(No.2021J02007)。
文摘Exploring the synthesis of novel structures is crucial for the development of functional materials.In this context,a novel and intriguing 3d-5p heterometallic cluster-substituted polyoxotungstate material,H_(29)Na_(9)(H_(2)O)_(21){Ca(H_(2)O)_(2)@Sb_(12)O_(18)[Ni_(2)(OH)(A-α-Si W_(10)O_(37))]_(3)}_(2)·40H_(2)O(1),was constructed using Keggintype polyoxotungstate A-α-Si W_(10)O_(37),along with Ni and Sb elements.The structure features a Tdsymmetric Sb_(12)O_(18)({Sb_(12)})cage that encapsulates an 8-coordinate Ca^(2+)ion at its face.Additionally,the{Sb_(12)}cage forms an 18-nuclear 3d-5p heterometallic cluster by connecting with three di-nuclear nickel clusters through shared oxygen atoms.Electrochemical impedance spectra studies reveal that the single crystal of 1 achieves a proton conductivity of 1.11×10^(-1)S/cm along the[110]direction and 1.04×10^(-1)S/cm along the[100]direction at 85℃ and 98%relative humidity(RH).Furthermore,the powder form of 1 exhibits a proton conductivity of 3.00×10^(-2)S/cm.These findings suggest that compound 1 holds promise as a practical proton conducting material.
基金supported by National Key Research and Development Program of China(No.2021YFB3502000)the National Natural Science Foundation of China(Nos.22309207,52325405,U21A20284,52261135632,51874358 and 51772333)。
文摘Conventional polycrystalline LiMn_(2)O_(4)(PC-LMO)suffers from poor Li^(+)diffusion rates and structural instability,negatively affecting its electrochemical performance.Here,we design a single-crystal LMO cathode material using BaO flux(SC-LMOB)to address these issues.The BaO flux enables the fabrication of brick-like single-crystal particles,enhancing Li^(+)diffusion by shortening the diffusion path and increasing the unit cell volume.This process also reduces the specific surface area and stabilizes the crystal structure,effectively mitigating Mn dissolution and polarization.As a result,SC-LMOB exhibits ultra-high rate performance and superior structural stability,retaining 88.8%of its capacity at a 20 C discharge rate and achieving capacity retentions of 85.3%and 86.0%after 500 and 300 cycles at 1 C at room and elevated temperatures,respectively.This structural design offers a low-cost,scalable approach for fabricating single-crystal cathode materials with excellent performance.
基金the National Natural Science Foundation of China(No.22274021)Natural Science Foundation of Fujian Province(No.2022J01535)for financial support。
文摘Covalent organic frameworks(COFs)have demonstrated great potential in chromatographic separation because of unique structure and superior performance.Herein,single-crystal three-dimensional(3D)COFs with regular morphology,good monodispersity and high specific surface area,were used as a stationary phase for high-performance liquid chromatography(HPLC).The single-crystal 3D COFs packed column not only exhibits high efficiency in separating hydrophobic molecules involving substituted benzenes,halogenated benzenes,halogenated nitrobenzenes,aromatic amines,aromatic hydrocarbons(PAHs)and phthalate esters(PAEs),but also achieves baseline separation of acenaphthene and acenaphthylene with similar physical and chemical properties as well as environmental pollutants,which cannot be quickly separated on commercial C18 column and a polycrystalline 3D COFs packed column.Especially,the column efficiency of 17303-24255 plates/m was obtained for PAEs,and the resolution values for acenaphthene and acenaphthylene,and carbamazepine(CBZ)and carbamazepine-10,11-epoxide(CBZEP)were 1.7and 2.2,respectively.This successful application not only confirmed the great potential of the singlecrystal 3D COFs in HPLC separation of the organic molecules,but also facilitates the application of COFs in separation science.
基金financially supported by the National Key Research&Development Plan(No.2020YFA0405900)the National Natural Science Foundation of China(Nos.52171117,52371113,and 92263201)+1 种基金the Tuoyuan Project of Nanjing Tech University(No.20230113)the Technological Projects from CRCC Qishuyan Institute Co.,LTD(No.BS24125).
文摘Quantifying the residual stress at micron-scale is crucial for comprehending the trans-and inter-granular deformation mechanisms and the influence of heat treatment,but remains technically challenging.This study utilized focused ion beam and digital image correlation(FIB-DIC)techniques to assess residual stress within the dendrite stem and arm of nickel-based single-crystal superalloys.The influence of hot isostatic pressing(HIP)on the microstructure and residual stress was also elucidated.Our results revealed that the residual stresses in the dendrite stem and arm regions manifest as tensile stress along the x-axis and compressive stress along the y-axis,with a range of−720 MPa to 680 MPa.HIP treatment effectively improved microstructure and regulated residual stress in nickel-based single-crystal superalloys,leading to a rapid reduction in residual stress levels.The present study lays a solid theoretical groundwork for optimizing processing strategies to regulate residual stress and enhance mechanical properties in next-generation single-crystal superalloys.
基金supported by the National Science and Technology Major Project of China(No.J2019-Ⅲ-0008-0051)the National Natural Science Foundation of China(Nos.52201140,52375225,and 92360307)the Natural Science Foundation for Youths of Shaanxi Province(No.2023-JC-QN-0521).
文摘Thermal barrier coating(TBC)is crucial for the performance of turbine blades at high temperatures;however,it degrades the microstructure of single-crystal superalloy(SX),thereby reducing creep life.Despite this,the degradation mechanisms associated with the complex multi-layer damage and inter-layer diffusion behavior for TBC/SX systems have not yet been fully elucidated.In this study,using integrated experimental efforts and multiscale characterization techniques,the creep degradation mechanisms of TBC/SX systems at 900℃/500 MPa,980℃/300 MPa,and 1050℃/160 MPa are systematically investigated.Results demonstrate that the creep degradation from TBC intensifies with increasing temperature(T)and stress(σ)ratio(T/σ),exhibiting significant dependency on these two factors,and primarily reduces lifespan of the steady-state stage,with minimal effects on the accelerating stage.During creep deformation,the cracking behavior caused by thermally grown oxide(TGO)beneath the top coat(TC)layer,voids resulting from internal oxidation and interdiffusion in the bond coat(BC)layer,and the recrystallization growth driven by the sandblasting process in the secondary reaction zone(SRZ)are temperature-sensitive damages.In contrast,the initiation and propagation of cracks associated with the topologically close-packed(TCP)phases in the SRZ exhibit pronounced stress sensitivity.Furthermore,the formation of the substrate diffusion zone(SDZ)and the decomposition ofγ/γ′interfacial dislocation networks driven by the Cr-Ru diffusion,as well as the increased stacking fault energy in theγ′phase due to Co loss,are responsible for the acceleration of steady-state creep rate at 1050℃/160 MPa.This work provides a comprehensive and in-depth understanding of the degradation mechanisms under thermal-mechanical coupling in TBC/SX systems,offering new insights into targeted design optimization for multilayered coatings.
基金Projects(50374082,5071112018)supported by the National Natural Science Foundation of China
文摘Based on the high-purity single-crystal tungsten nanowire firstly prepared by the metal-catalyzed vapor-phase reaction method, molecular dynamics method was used to calculate tensile stress-strain curves and simulate microscopic deformation structures of the single-crystal tungsten nanowires with different crystal orientations of 〈100〉, 〈110〉and 〈111〉, in order to reveal the effect of crystal orientation on their tensile mechanical properties and failure mechanisms. Research results show that all of the stress-strain curves are classified into four stages： elastic stage, damage stage, yielding stage and failure stage, where 〈100〉orientation has a special hardening stage after yielding and two descending stages. The crystal orientation has little effect on elastic modulus but great effect on tensile strength, yielding strength and ductility, depending on different atomic surface energies and principal sliding planes. The calculated values of elastic modulus are in good agreement with the tested values of elastic modulus.
基金Project (2010ZF21007) supported by the Aeronautical Science Foundation of China
文摘The dynamic recrystallization behavior of single-crystal（SC） superalloy SR.R99 at low strain rate was investigated by high-temperature creep testing.The results show that dynamic recrystallization may take place after the uncoated samples have been creep-tested in air at high temperature and low stress for a long time.Both the threshold temperature and strain for the dynamic recrystallization of SC superalloy SRR99 at low strain rate are lower than those for the static recrystallization.Dynamically recrystallized grains with the depth less than 15 μm are only located in the surface γ＇-free layers,and the recrystallized grains are well-developed grains without columnar y＇precipitates within them.The dynamic recrystallization behavior of SC superalloy SRR99 at low strain rate is mainly related to high-temperature oxidation.Suitable protective coating can effectively prevent the dynamic recrystallization of SC superalloy components in service.In addition,the dynamic recrystallization behavior of SC superalloy SRR99 at high strain rate was also studied by high-temperature compression testing.At high strain rate,a higher temperature and larger strain are needed for the occurrence of dynamic recrystallization than at low strain rate,and the recrystallized grains have cellular structures with an amount of columnar γ＇ precipitates within them.
基金financial supports from the National Natural Science Foundation of China (51974368)the Fundamental Research Funds of the Central South University,China。
文摘Single-crystal Ni-rich cathode material LiNi0.88Co0.09Al0.03O2(SC) was synthesized by a high-temperature solid-state calcination method. Physicochemical properties of primary and delithiated SC samples were investigated by X-ray diffractometry, X-ray photoelectron spectroscopy, and transmission electron microscopy. Electrochemical performance was characterized by long-term cycling, cyclic voltammetry, and in-situ impedance spectroscopy. The results indicated that high temperature rendered layered oxides to lose lithium/oxygen in the interior and exterior, and induced cationic disordering. Besides, the solid-phase synthesis process promoted phase transformation for electrode materials, causing the coexisting multi-phase in a single particle. High temperature can foster the growth of single particles, but it caused unstable structure of layered phase.
基金the National Natural Science Foundation of China Nos.51671053 and 51801021the Ministry of Industry and Information Technology Project No.MJ-2017-J-99)。
文摘MCrAlY(M=Ni and/or Co)overlay coating is widely used as a protective coating against high temperature oxidation and corrosion.However,due to its big difference in chemical composition with the underlying superalloy,elements interdiffusion occurs inevitably.One of the direct results is the formation of interdiffusion zone(IDZ)and secondary reaction zone(SRZ)with a high density of fine topological closed-packed phases(TCPs),weakening dramatically the mechanical properties of the alloy substrate.It is by now the main problem of modern high-temperature metallic coatings,but there are still hardly any reports studying the formation,growth and transformation of IDZ and SRZ in deep,as well as the precipitation of TCPs.In this work,a typical NiCrAlY coating is deposited by arc ion plating on a single-crystal superalloy N5.Elements interdiffusion between them and its relationship on microstructure were clarified.Cr rather than Al from the coating diffuses into the alloy at high temperatures and segregates immediately beneath their interface,contributing largely to the formation of IDZ.Simultaneously,diffusion of Ni from the deep alloy to IDZ leads to the formation and continuous expansion of SRZ.
基金This work was financially supported by the Natural Science Foundation of Beijing,China(No.4192038)National Key Research and Development Program of China(Nos.2016YFE0133200 and 2018YFB0406501)European Union’s Horizon 2020 Research and Innovation Staff Exchange Scheme(No.734578).
文摘Chemical vapor deposition(CVD)-grown diamond films have been developed as irradiation-resistant materials to replace or upgrade current detectors for use in extreme radiation environments. However, their sensitivity in practical applications has been inhibited by space charge stability issues caused by defects and impurities in pure diamond crystal materials. In this study, two high-quality CVD-grown single-crystal diamond(SCD) detectors with low content of nitrogen impurities were fabricated and characterized. The intrinsic properties of the SCD samples were characterized using Raman spectroscopy, stereomicroscopy, and X-ray diffraction with the rocking curve mode, cathode luminescence(CL), and infrared and ultraviolet-visible-near infrared spectroscopies. After packaging the detectors, the dark current and energy resolution under α particle irradiation were investigated. Dark currents of less than 5 pA at 100 V were obtained after annealing the electrodes, which is comparable with the optimal value previously reported. The detector that uses a diamond film with higher nitrogen content showed poor energy resolution, whereas the detector with more dislocations showed poor charge collection efficiency(CCE). This demonstrates that the nitrogen content in diamond has a significant effect on the energy resolution of detectors, while the dislocations in diamond largely contribute to the poor CCE of detectors.
基金financially supported by the National Natural Science Foundation of China (Nos. 51871210,51671196, 51631008 and 51771204)the National Key Research and Development Program of China (No. 2016YFB0701403).
文摘The influence of orientation on the stress rupture behaviors of a 3 rd-generation nickel-based single-crystal superalloy was investigated at 1100℃/150 MPa.It is found that the stress rupture anisotropy is shown at 1100℃,but not so obvious compared with that at intermediate temperatures.The [001] specimens display the longest rupture life,[111] specimens show the shortest rupture life,and [011] specimens exhibit the intermediate life.Detailed observations show that the final fracture is caused by crack initiation and propagation,and the anisotropy of three oriented specimens is related to the fracture modes,γ/γ’ microstructures,interfacial dislocation networks and cutting mechanisms in y’ phase.For [001] specimens,N-type rafted structures are formed which can well hinder the slip and climb of dislocations.Besides,the regular interfacial dislocation networks can prevent dislocations from cutting into y’ phase,leading to the improvement of the creep resistance.For [011] specimens,±45°rafted structures and irregular networks result in less strain hardening.For [111] specimens,a large number of crack propagation paths and inhomogeneous deformations caused by irregular rafted structures deteriorate the property and result in the shortest life.Furthermore,a[100] superdislocations with low mobility are widely formed in[001] and [011] specimens which suggests the low creep strain rate during steady creep stage,whereas superdislocations in[111] specimens possess high mobility,which indicates the high strain rate and corresponding poor stress rupture property.
基金financially supported by Jiangsu Province Key Technology R&D(Industry)Program(No.BE201217)the Science and Technology Innovation Fund Program(Nos.CX2011028 and CX2011029)+1 种基金the Cooperative Innovation Fund of Jiangsu Province(No.BY2014004-09)the Foundation of Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology(No.ASMA201403)
文摘The isothermal oxidation behavior of a new Refree nickel-based single-crystal superalloy in air at 950 ℃ for 200 h was studied by scanning electron microscopy（SEM）with energy-dispersive spectroscopy（EDS）and X-ray diffraction（XRD）.The results indicate that oxidation kinetics obeys parabolic law approximately,and the mass gain increases rapidly during initial oxidation stage and then gradually slows down.The oxidation scales are composed of three layers：the outer layer mainly consists of NiO with a small amount of CoO;the intermediate layer is mainly composed of Cr_2O_3 with a small amount of spinel compounds such as CrTaO_4,NiCr_2O_4,CoCrAl_2O_4,CoAl_2O_4,and NiAl_2O_4;and the inner layer is composed of Al_2O_3.Inner Al_2O_3 layer suppresses the diffusion of elements between oxygen and alloy elements,slows down the alloy oxidation speed,and also suppresses the growth of the oxide scale and reduces the oxidation rate,which is agreeable with the oxidation kinetics.
基金financially supported by the National Natural Science Foundation of China(Nos.51774150 and 51974137)。
文摘Single-crystal LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(SC-811),which offers better cycle performance compared to the polycrystalline counterpart,has received great attention.We report herein the synthesis of SC-811 with a grain size of 2-4μm by washing and reheating method,which compares with conventional polycrystalline LiNi_(0.8)-Co_(0.1)Mn_(0.1)O_(2)(PC-811).The discharge capacity of SC-811 reaches 152.1 mAh·g^(-1)after 100 cycles(86.7%capacity retention)at 1.0 C,which is much better than that of PC-811(130.2 mAh·g^(-1),73.8%capacity retention).By using multiscale characterization,the results unveil that SC-811 can not only improve the reversibility of the H2-H3 phase transitions,suppress the generation of micro-cracks and phase transformations,but also mitigate the undesired side reactions between electrode and electrolyte.Besides,the Li-O bond of SC-811 is longer than that of PC-811,which is conducive to the de-intercalation of Li-ions,thereby enhancing the structural stability.This finding provides an impressive strategy to sustain structural stability and improve the cycling life of Ni-rich layered cathodes.
基金supported by the National Natural Science Foundation of China (Nos. 51571196, 51671188 and 5160119)Shenyang Science and Technology Project (No. 17-101-2-00)
文摘The influence of crystal orientations on the low-cycle fatigue(LCF) behavior of a 3Re-bearing Ni-based single-crystal superalloy at 980 °C has been investigated. It is found that the orientation dependence of the fatigue life not only depends on the elastic modulus, but also the number of active slip planes and the plasticity of materials determine the LCF life,especially for the [011] and [111] specimens. The [011] and [111] specimens with better plasticity withstand relatively concentrated inelastic deformation caused by fewer active slip planes, compared to the [001] specimens resisting widespread deformation caused by a higher number of active slip planes. Additionally, fatigue fracture is also influenced by cyclic plastic deformation mechanisms of the alloy with crystal orientations, and the [001] specimens are plastically deformed by wave slip mechanism and fracture along the non-crystallographic plane, while the [011] and [111] specimens are plastically deformed by planar slip mechanism and fracture along the crystallographic planes. Moreover, casting pores,eutectics, inclusions and surface oxide layers not only initiate the crack, but also reduce the stress concentration around crack tips. Our results throw light upon the effect of inelastic strain on the LCF life and analyze the cyclic plastic deformation for the alloy with different orientations.
基金supported financially by the National Natural Science Foundation of China(No.51774212)。
文摘The effect of theγ+γtwo-phase structure on the oxidation behaviors of Ni-Al single-crystal alloys at 650℃was investigated by scanning electron microscopy,transmission electron microscopy,atomic force microscopy,X-ray diffraction and Auger electron spectroscopy.In the initial oxidation stage,the oxidation behavior is primarily determined by the growth pattern of oxides in theγchannel.The outward convex NiO was formed in unprotected wideγchannels.And Ni-Al spinel oxide provides a great number of short-circuit paths,accelerating the inward diffusion of oxygen and outward diffusion of Ni.In the late stage of oxidation,the elongated internal oxide in the largeγphase contributes to the diffusion of oxygen along the oxide/metal interface.Consequently,the Ni-Al single-crystal alloy with wideγchannels and largeγprecipitates exhibited poor oxidation performance.
基金supported by the Shenzhen Science and Technology Innovation Commission under project No. JCYJ20170817111811303
文摘A successful repair of single-crystal components needs to avoid the stray grain formation and achieves continuous epitaxial growth of columnar dendrites in the repaired zone. In this study, the effect of substrate preset temperature on crystal growth and microstructure formation in laser powder deposition of single-crystal superalloy was studied through an improved mathematical model and corresponding experimental approaches. The results indicated that the variation of substrate preset temperature between-30℃ and ＋210℃ changes the molten pool morphology little, but obviously affects the columnar-to-equiaxed transition conditions. The preheating of substrate facilitates the stray grain formation and enlarges the primary columnar dendrite arm spacing, while the situation for precooling of substrate is opposite. Under the specific processing conditions, the critical condition for continuous epitaxial growth is that the substrate preset temperature Tsub≤ ＋90℃. When the substrate preset temperature Tsubis below ＋90℃, the height ratio of melting depth to total height of the molten pool is larger than that of stray grain, ensuring that stray grains can be completely remelted and the continuous columnar dendrites during the multi-layer laser powder deposition process on（001） surface of single-crystal substrate can be achieved.
基金This work was supported by the Natural Science Foundation of China(Grant No.11704389)Scientific Equipment Development Project and Youth Innovation Promotion Association Project of Chinese Academy of Sciences.
文摘Epitaxial high-crystallization film semiconductor heterostructures has been proved to be an effective method to prepare single-crystal films for different functional devices in modern microelectronics,electro-optics,and optoelectronics.With superior semiconducting properties,halide perovskite materials are rising as building blocks for heterostructures.Here,the conformal vapor phase epitaxy of CsPbBr3 on PbS single-crystal films is realized to form the CsPbBr3/PbS heterostructures via a two-step vapor deposition process.The structural characterization reveals that PbS substrates and the epilayer CsPbBr3 have clear relationships:CsPbBr3(110)//PbS(100),CsPbBr3[001]//PbS[001]and CsPbBr3[001]//PbS[010].The absorption and photoluminescence(PL)characteristics of CsPbBr3/PbS heterostructures show the broadband light absorption and efficient photogenerated carrier transfer.Photodetectors based on the heterostructures show superior photoresponsivity of 15 A/W,high detectivity of 2.65×10^(11) Jones,fast response speed of 96 ms and obvious rectification behavior.Our study offers a convenient method for establishing the high-quality CsPbBr3/PbS single-crystal film heterostructures and providing an effective way for their application in optoelectronic devices.
