In order to explore the effect of vacancy defects on the structural,electronic,magnetic and optical properties of CoS_(2) and FeS_(2),first-principles calculation method was used to investigate the alloys.The calculat...In order to explore the effect of vacancy defects on the structural,electronic,magnetic and optical properties of CoS_(2) and FeS_(2),first-principles calculation method was used to investigate the alloys.The calculated results of materials without vacancy are consistent with those reported in the literatures,while the results of materials with vacancy defect were different from those of literatures due to the difference vacancy concentration.The Co vacancy defect hardly changes the half-metallic characteristic of CoS_(2).The Fe vacancy defect changes FeS_(2) from semiconductor to half-metal,and the bottom of the spin-down conduction band changes from the p orbital state of S to the d(t_(2g))orbital state of Fe,while the top of the valence band remains the d orbital d(eg)state of Fe.The half-metallic Co vacancy defects of CoS_(2) and Fe vacancy defects of FeS_(2) are expected to be used in spintronic devices.S vacancy defects make both CoS_(2) and FeS_(2) metallic.Both the Co and S vacancy defects lead to the decrease of the magnetic moment of CoS_(2),while both the Fe and S vacancy defects lead to the obvious magnetic property of FeS_(2).Vacancy defects enhance the absorption coefficient of infrared band and long band of visible light obviously,and produce obvious red shift phenomenon,which is expected to be used in photoelectric devices.展开更多
Improving brittle behavior and mechanical properties is still a big challenge for high-temperature structural materials.By means of first-principles calculations,in this paper,we systematically investigate the effect ...Improving brittle behavior and mechanical properties is still a big challenge for high-temperature structural materials.By means of first-principles calculations,in this paper,we systematically investigate the effect of vacancy and oxygen occupation on the elastic properties and brittle-or-ductile behavior on Mo_(5)Si_(3).Four vacancies(Si_(-Va1),Si_(-Va2),Mo_(-Va1),Mo_(-Va2))and oxygen occupation models(O_(Mo1),O_(Mo2),O_(-Si1),O_(-Si2))are selected for research.It is found that Mo_(-Va2) vacancy has the stronger structural stability in the ground state in comparison with other vacancies.Besides,the deformation resistance and hardness of the parent Mo_(5)Si_(3) are weakened due to the introduction of different vacancy defects and oxygen occupation.The ratio of B/G indicates that oxygen atoms occupation and vacancy defects result in brittle-to-ductile transition for Mo_(5)Si_(3).These vacancies and the oxygen atoms occupation change the localized hybridization between Mo-Si and Mo-Mo atoms.The weaker O-Mo bond is a contributing factor for the excellent ductile behavior in the O_(-Si2) model for Mo_(5)Si_(3).展开更多
The effects of vacancy defects on the thermal conductivity of Ge thin films were investigated by employing molecular dynamics （MD） simula- tions and theoretical analysis based on the Boltzmann equation. Both the MD ...The effects of vacancy defects on the thermal conductivity of Ge thin films were investigated by employing molecular dynamics （MD） simula- tions and theoretical analysis based on the Boltzmann equation. Both the MD and theoretical results show that the lattice thermal conductivity dramatically decreases with the increasing of vacancy concentration at 400 and 500 K. In addition, the dependence of vacancy concentration on the thermal conductivity of Ge thin films becomes less sensitive as the temperature increases. Theoretical results also confirm that the major part of the lattice thermal conductivity reduction is associated with the point-defect scattering and phonon-phonon scattering processes.展开更多
The electronic properties of sphalerite(110) surface with Zn-vacancy and S-vacancy were calculated by using density-functional theory,and the effects of vacancy defect on the copper activation of sphalerite were inves...The electronic properties of sphalerite(110) surface with Zn-vacancy and S-vacancy were calculated by using density-functional theory,and the effects of vacancy defect on the copper activation of sphalerite were investigated.The calculated results indicate that surface state occurs in the band gap of Zn-vacancy sphalerite,which is from the contribution of S 3p orbital at the first layer of the surface.The presence of S-vacancy results in surface state appearing near the Fermi level and the bottom of conductor band,which are composed of S 3p and Zn 4s orbital,respectively.The surface structure of Zn-vacancy sphalerite is more stable than S-vacancy surface due to the occupation of Zn-vacancy by Cu atoms;hence,the substitution reaction of Cu for Zn vacancy is easier than the substitution of Cu for Zn atoms with S-vacancy surface.展开更多
The therapeutic efficacy of cuproptosis,ferroptosis,and apoptosis is hindered by inadequate intracellular copper and iron levels,hypoxia,and elevated glutathione(GSH)expression in tumor cells.Thermoelectric technology...The therapeutic efficacy of cuproptosis,ferroptosis,and apoptosis is hindered by inadequate intracellular copper and iron levels,hypoxia,and elevated glutathione(GSH)expression in tumor cells.Thermoelectric technology is an emerging frontier in medical therapy that aims to achieve efficient thermal and electrical transport characteristics within a narrow thermal range for biological systems.Here,we systematically constructed biodegradable Cu_(2)MnS_(3-x)-PEG/glucose oxidase(MCPG)with sulfur vacancies(S_(V))using photothermoelectric catalysis(PTEC),photothermal-enhanced enzyme catalysis,and starvation therapy.This triggers GSH consumption and disrupts intracellular redox homeostasis,leading to immunogenic cell death.Under 1064 nm laser irradiation,MCPG enriched with S_(V),owing to doping,generates a local temperature gradient that activates PTEC and produces toxic reactive oxygen species(ROS).Hydroxyl radicals and oxygen are generated through peroxide and catalase-like processes.Increased oxygen levels alleviate tumor hypoxia,whereas hydrogen peroxide production from glycometabolism provides sufficient ROS for a cascade catalytic reaction,establishing a self-reinforcing positive mechanism.Density functional theory calculations demonstrated that vacancy defects effectively enhanced enzyme catalytic activity.Multimodal imaging-guided synergistic therapy not only damages tumor cells,but also elicits an antitumor immune response to inhibit tumor metastasis.This study offers novel insights into the cuproptosis/ferroptosis/apoptosis pathways of Cu-based PTEC nanozymes.展开更多
Vacancy defects,as fundamental disruptions in metallic lattices,play an important role in shaping the mechanical and electronic properties of aluminum crystals.However,the influence of vacancy position under coupled t...Vacancy defects,as fundamental disruptions in metallic lattices,play an important role in shaping the mechanical and electronic properties of aluminum crystals.However,the influence of vacancy position under coupled thermomechanical fields remains insufficiently understood.In this study,transmission and scanning electron microscopy were employed to observe dislocation structures and grain boundary heterogeneities in processed aluminum alloys,suggesting stress concentrations and microstructural inhomogeneities associated with vacancy accumulation.To complement these observations,first-principles calculations and molecular dynamics simulations were conducted for seven single-vacancy configurations in face-centered cubic aluminum.The stress response,total energy,density of states(DOS),and differential charge density were examined under varying compressive strain(ε=0–0.1)and temperature(0–600 K).The results indicate that face-centered vacancies tend to reduce mechanical strength and perturb electronic states near the Fermi level,whereas corner and edge vacancies appear to have weaker effects.Elevated temperatures may partially restore electronic uniformity through thermal excitation.Overall,these findings suggest that vacancy position exerts a critical but position-dependent influence on coupled structure-property relationships,offering theoretical insights and preliminary experimental support for defect-engineered aluminum alloy design.展开更多
L1_(0)-FePt nanoparticles(NPs)are urgently anticipated because of their promising applications.However,the preparation of the NPs with both of high ordering degree and super-fine size is still a challenge.Inspired by ...L1_(0)-FePt nanoparticles(NPs)are urgently anticipated because of their promising applications.However,the preparation of the NPs with both of high ordering degree and super-fine size is still a challenge.Inspired by recent studies on the effect of vacancy defects on structural ordering,we proposed an intentional vacancy defect design strategy for directly synthesizing highly ordered FePt NPs.In the present work,we used the first-principle calculations to investigate the influence of doping typical elements(Cu,Ag,and Pb)on the vacancy formation energy(E_(vac))of FePt NPs.The vacancy defects were effectively formed by introducing elements of larger atomic radii and higher propensity for segregation into the FePt lattice,facilitating the diffusion of Fe and Pt atoms.The Pb doping showed remarkable efficacy in promoting the ordering transition.Experimentally,wet-chemical synthesis confirmed the success of the proposed strategy in achieving highly ordered L1_(0)-FePt NPs with exceptional magnetic properties and super-fine size(ordering degree of 0.896,impressive coercivity of 21.74 kOe,and small particle size of 9.02 nm).Additionally,we have deduced a diffusion model elucidating the formation process of the ordered FePt NPs,focusing on the migration of Pb atoms from the center to the surface of the particles.This migration is demonstrated to generate more vacancies and promote the transition to the ordered L1_(0)-FePt phase.The findings of this research offer valuable insights into synthesizing highly ordered and ultrafine L1_(0)-type nanomaterials.展开更多
Recently,high-entropy materials are attracting enormous attention in battery applications,encompassing both electrode materials and solid electrolytes,due to the pliability and diversification in material composition ...Recently,high-entropy materials are attracting enormous attention in battery applications,encompassing both electrode materials and solid electrolytes,due to the pliability and diversification in material composition and electronic structure.Theoretically,the rapid ion transport and the abundance of surface defects in high-entropy materials suggest a potential for enhancing the performance of composite solid-state electrolytes(CPEs).Herein,using a high-entropy oxide(HEO)filler to assess its potential contributions to CPEs is proposed.The distinctive structural distortions in HEO significantly improve the ionic conductivity(5×10^(−4) S·cm^(−1) at 60℃)and Li-ion transference number(0.57)of CPEs.Furthermore,the enhanced Li-ion transport capability extends the critical current density from 0.6 to 1.5 mA·cm^(−2) in Li/Li symmetric cells.In addition,all-solid-state batteries incorporating the HEO-modified CPEs exhibit superior rate performance and cycling stability.The work will enrich the application of HEOs in CPEs and provide fundamental understanding.展开更多
Bismuth titanate (Bi_(4)Ti_(3)O_(12),BIT)piezoelectric materials have attracted increasing attention due to their high-temperature applications.However,it is quite challenging to simultaneously achieve outstanding pie...Bismuth titanate (Bi_(4)Ti_(3)O_(12),BIT)piezoelectric materials have attracted increasing attention due to their high-temperature applications.However,it is quite challenging to simultaneously achieve outstanding piezoelectric properties and high Curie temperature in BIT-based systems.In this study,oxygen vacancy defects tailoring strategy was utilized to solve this problem,excellent piezoelectric coefficient(32.1 pC/N),and ultrahigh Curie temperature(659℃)are gotten in Bi_(4)Ti_(3)-x(Mn_(1/3)Nb_(2/3))xO_(12)(BTMN)ceramics,which are among the top values in the BIT-based ceramics.More importantly,the(Mn_(1/3)Nb_(2/3))(4+d)+complex-ion modified Bi_(4)Ti_(3)O_(12)-based ceramics are characterized with excellent piezoelectric stability up to 500℃(d33>30.0 pC/N at 500℃))and significantly reduced conductivity(only~10^(-7)U-1 cm^(-1)at 500℃).Moreover,enhanced ferroelectricity and good dielectric stability were also obtained.The better comprehensive properties can be ascribed to two aspects.First,the concentration of oxygen vacancy defects is obviously reduced,and their distribution is effectively controlled in BITMN ceramics.Second,the introduction of(Mn_(1/3)Nb_(2/3))^((4+δ)+)complex-ion gives rise to the antiphase boundaries and massive ferroelectric domain walls.This works not only reveal the high potential of BITMN ceramics for high-temperature piezoelectric applications but also deepen the understanding of the structure-properties relationship in BIT-based materials.展开更多
MoS_(2)is a promising electrocatalyst because of its natural abundance and outstanding electrochemical stability.However,the poor conductivity and low activity limit its catalytic performance;furthermore,MoS_(2)is una...MoS_(2)is a promising electrocatalyst because of its natural abundance and outstanding electrochemical stability.However,the poor conductivity and low activity limit its catalytic performance;furthermore,MoS_(2)is unable to satisfy the requirements of most industrial applications.In this study,to obtain a P-doped MoS_(2)catalyst with S vacancy defects,P is inserted into the MoS_(2)matrix via a solid phase ion exchange at room temperature.The optimal P-doping amount is 11.4 wt%,and the resultant catalyst delivers excellent electrocatalytic properties for the hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)with the corresponding overpotentials of 93 and 316 mV at 10 mA cm^(-2) in an alkaline solution;these values surpass the overpotentials of most previously reported MoS_(2)-based materials.Theoretical calculations and results demonstrate that the synergistic effect of the doped P,which forms active centers in the basal plane of MoS_(2),and S vacancy defects caused by P doping intensifies the intrinsic electronic conductivity and electrocatalytic activity of the catalyst.Density functional theory calculations demonstrate that P optimizes the free energy of the MoS_(2)matrix for hydrogen adsorption,thereby considerably increasing the intrinsic activity of the doped catalyst for the HER compared with that observed from pristine MoS_(2).The enhanced catalytic activity of P-doped MoS_(2)for the OER is attributed to the ability of the doped P which facilitates the adsorption of hydroxyl and hydroperoxy intermediates and reduces the reaction energy barrier.This study provides a new environmentally friendly and convenient solid-phase ion exchange method to improve the electrocatalytic capability of two-dimensional transition-metal dichalcogenides in largescale applications.展开更多
Photo-induced vacancy defects are employed strategically to imbue semiconductors with enhanced performance characteristics for many important applications such as surface-enhanced Raman scattering(SERS)sensing,photoca...Photo-induced vacancy defects are employed strategically to imbue semiconductors with enhanced performance characteristics for many important applications such as surface-enhanced Raman scattering(SERS)sensing,photocatalysis,and photovoltaic applications.However,the long-term maintenance and use of photo-induced vacancy defects remain elusive,because of their rapid self-healing upon air exposure.In this study,we demonstrate that photo-induced oxygen vacancy(PIVO)defects can be stabilized by the photoexcitation of metal–organic framework(MOF)materials,which is crucial for SERS analysis.The PIVO defects in MOF materials are stable for at least two weeks in the ambient atmosphere,owing to the combination of steric hindrance and electron delocalization around vacancy defects,which significantly contrasts the short lifetime(within minutes)of PIVO defects in metal-oxide semiconductors.With the formation of stable PIVO defects,a prominent SERS enhancement surpassing that of pristine MOFs is achieved,accompanied with a reduced limit of detection by three orders of magnitude.Moreover,the additional SERS enhancement rendered by PIVO defects can be stably retained and is effective for monitoring various small molecules,such as dopamine and bisphenol A.展开更多
Recently,the newly synthesized septuple-atomic layer two-dimensional(2D)material MoSi_(2)N_(4)(MSN)has attracted attention worldwide.Our work delves into the effect of vacancies and external electric fields on the ele...Recently,the newly synthesized septuple-atomic layer two-dimensional(2D)material MoSi_(2)N_(4)(MSN)has attracted attention worldwide.Our work delves into the effect of vacancies and external electric fields on the electronic properties of the MSN/graphene(Gr)heterostructure using first-principles calculation.We find that four types of defective structures,N-in,N-out,Si and Mo vacancy defects of monolayer MSN and MSN/Gr heterostructure are stable in air.Moreover,vacancy defects can effectively modulate the charge transfer at the interface of the MSN/Gr heterostructure as well as the work function of the pristine monolayer MSN and MSN/Gr heterostructure.Finally,the application of an external electric field enables the dynamic switching between n-type and p-type Schottky contacts.Our work may offer the possibility of exceeding the capabilities of conventional Schottky diodes based on MSN/Gr heterostructures.展开更多
Role of vacancy-type（N vacancy（VN） and Ga vacancy（VGa）） defects in magnetism of GaMnN is investigated by first-principle calculation.Theoretical results show that both the VNand VGainfluence the ferromagnetic st...Role of vacancy-type（N vacancy（VN） and Ga vacancy（VGa）） defects in magnetism of GaMnN is investigated by first-principle calculation.Theoretical results show that both the VNand VGainfluence the ferromagnetic state of a system.The VNcan induce antiferromagnetic state and the VGaindirectly modify the stability of the ferromagnetic state by depopulating the Mn levels in GaMnN.The transfer of electrons between the vacancy defects and Mn ions results in converting Mn3＋（d4） into Mn2＋（d5）.The introduced VNand the ferromagnetism become stronger and then gradually weaker with Mn concentration increasing,as well as the coexistence of Mn3＋（d4） and Mn2＋（d5） are found in GaMnN films grown by metal–organic chemical vapor deposition.The analysis suggests that a big proportion of Mn3＋changing into Mn2＋will reduce the exchange interaction and magnetic correlation of Mn atoms and lead to the reduction of ferromagnetism of material.展开更多
The Young＇s modulus of graphene with various rectangular and circular vacancy defects is investigated by molecular dynamics simulation. By comparing with the results calculated from an effective spring model, it is d...The Young＇s modulus of graphene with various rectangular and circular vacancy defects is investigated by molecular dynamics simulation. By comparing with the results calculated from an effective spring model, it is demonstrated that the Young＇s modulus of graphene is largely correlated to the size of vacancy defects perpendicular to the stretching direction. And a linear reduction of Young＇s modulus with the increasing concentration of monoatomic-vacancy defects （Le., the slope of =0.03） is also observed. The fracture behavior of graphene, including the fracture strength, crack initiation and propagation are then studied by the molecular dynamics simulation, the effective spring model, and the quantized fracture mechanics. The blunting effect of vacancy edges is demonstrated, and the characterized crack tip radius of 4.44 A is observed.展开更多
The vacancy defect exhibits a remarkable improvement in the dehydriding property of MgH_(2)@Ni-CNTs.However,the corresponding mechanism is still not fully understood.Herein,the impact of vacancy defects on the dehydro...The vacancy defect exhibits a remarkable improvement in the dehydriding property of MgH_(2)@Ni-CNTs.However,the corresponding mechanism is still not fully understood.Herein,the impact of vacancy defects on the dehydrogenation properties of MgH_(2)@Ni-CNTs was studied by DFT simulation,and the corresponding models were constructed based on MS.The dehydrogenation process of MgH_(2)can be regarded as the dissociation of Mg-H and desorption of H_(2)from the MgH_(2)surface.In view of the whole dehydrogenation,the dissociation of H^(−)is the rate-determining step,which is the main reason for restricting the dehydrogenation kinetics.Compared with vacancy vacancy-defective MgH_(2)(001)surface,the appearance of vacancy defects on the(110)surface substantially reduces the energy barrier required for H dissociation to 0.070 Ha.The reason is that vacancy defects accelerate the transition of electrons from the H^(−)s orbit to the Mg^(2+)3s orbit,resulting in a decrement of the Mg-H bond strength,which makes H atoms more easily dissociated from the MgH_(2)(110)surface.Therefore,the existence of vacancy defects improves the dehydriding kinetic of MgH_(2).Most importantly,this research offers crucial directions for developing hydrogen storage materials as well as a potential fix for the slow dehydrogenation kinetics of nano-confined MgH_(2).展开更多
Based on first-principle calculations, the electronic structures and optical properties of a single-walled （7, 0） SiC nanotube （SiCNT） with a carbon vacancy defect or a silicon vacancy defect are investigated. In ...Based on first-principle calculations, the electronic structures and optical properties of a single-walled （7, 0） SiC nanotube （SiCNT） with a carbon vacancy defect or a silicon vacancy defect are investigated. In the three silicon atoms around the carbon vacancy, two atoms form a stable bond and the other is a dangling bond. A similar structure is found in the nanotube with a silicon vacancy. A carbon vacancy results in a defect level near the top of the valence band, while a silicon vacancy leads to the formation of three defect levels in the band gap of the nanotube. Transitions between defect levels and energy levels near the bottom of the conduction band have a close relationship with the formation of the novel dielectric peaks in the lower energy range of the dielectric function.展开更多
High performances of Cu_(2)ZnSn(S,Se)_(4)(CZTSSe)solar cells are heavily influenced by the quality of heterojunctions.Herein,an oxygen(O)doping of CZTSSe/CdS heterojunction is performed to suppress the formation of th...High performances of Cu_(2)ZnSn(S,Se)_(4)(CZTSSe)solar cells are heavily influenced by the quality of heterojunctions.Herein,an oxygen(O)doping of CZTSSe/CdS heterojunction is performed to suppress the formation of the defects by an ultraviolet ozone(UV-O_(3))treatment for the efficient flexible CZTSSe solar cells.The introduction of O reduces the non-radiative recombination and increases the carrier concentration of the CdS films.Furthermore,the defect density of the CdS film has been reduced from 8.24×10^(16)to2.91×10^(16)cm^(-3)by the O-doping.The results indicate that the electron transport is effectively promoted due to the decreased conduction band offset(CBO)at the heterojunction interface.As a result,the champion flexible CZTSSe solar cell achieves a power conversion efficiency(PCE)of 11.21%,with a significantly improved short circuit current density.The study for improving the CZTSSe/CdS heterojunction through O-doping treatment provides a new insight for enhancing the PCE of the flexible CZTSSe solar cells.展开更多
The defect chemistry is successfully modulated on free-standing and binder-free carbon cathodes for highly efficient Li-S redox reactions.Such rationally regulated defect engineering realizes the synchronization of io...The defect chemistry is successfully modulated on free-standing and binder-free carbon cathodes for highly efficient Li-S redox reactions.Such rationally regulated defect engineering realizes the synchronization of ion/electron-conductive and defect-rich networks on the threedimension carbon cathode,leading to its tunable activity for both relieving the shuttle phenomenon and accelerating the sulfur redox reaction kinetics.As expected,the defective carbon cathode harvests a high rate capacity of 1217.8 mAh g^(-1)at 0.2 C and a superior capacity retention of61.7%at 2 C after 500 cycles.Even under the sulfur mass loading of 11.1 mg cm^(-2),the defective cathode still holds a remarkable areal capacity of 8.5 mAh cm^(-2).展开更多
We describe here a one-step method for the synthesis of Au/TiO2 nanosphere materials,which were formed by layered deposition of multiple anatase TiO2 nanosheets.The Au nanoparticles were stabilized by structural defec...We describe here a one-step method for the synthesis of Au/TiO2 nanosphere materials,which were formed by layered deposition of multiple anatase TiO2 nanosheets.The Au nanoparticles were stabilized by structural defects in each TiO2 nanosheet,including crystal steps and edges,thereby fixing the Au-TiO2 perimeter interface.Reactant transfer occurred along the gaps between these TiO2 nanosheet layers and in contact with catalytically active sites at the Au-TiO2 interface.The doped Au induced the formation of oxygen vacancies in the Au-TiO2 interface.Such vacancies are essential for generating active oxygen species（-＊O^-） on the TiO2 surface and Ti^3＋ ions in bulk TiO2.These ions can then form Ti^3＋-O^--Ti^4＋species,which are known to enhance the catalytic activity of formaldehyde（HCHO） oxidation.These studies on structural and oxygen vacancy defects in Au/TiO2 samples provide a theoretical foundation for the catalytic mechanism of HCHO oxidation on oxide-supported Au materials.展开更多
The NiOx,due to its excellent semiconductor properties,ease of large-area deposition,and tunable optoelectronic characteristics,shows great potential in industrial large-area perovskite technologies.However,NiO_(x)-ba...The NiOx,due to its excellent semiconductor properties,ease of large-area deposition,and tunable optoelectronic characteristics,shows great potential in industrial large-area perovskite technologies.However,NiO_(x)-based perovskite solar cells(PSCs)are limited by interfacial photocatalytic chemical reactions and energy level mismatch.Thus,phosphate-based self-assembled monolayers(SAMs)have been widely developed for delicate interfacial modification;however,they suffer from severe issues such as self-aggregation and high cost.Herein,a low-cost carboxylate-based SAM(pyrenebutyric acid,PyBA)was used to modify NiO_(x),achieving an improved surface chemical environment and interfacial properties,such as an increased Ni^(3+)/Ni2^(+)ratio,a reduced proportion of high-valence Ni^(≥3+),and better-aligned hole transport interface energy level.The introduction of PyBA also results in larger grain size,higher uniformity,and enhanced photoluminescence(PL)from the bottom of the perovskite,yielding a significant increase in efficiency from an initial 22.48%to 25.14%,while increasing the open-circuit voltage(VOC)from 1.077 to 1.192 V.Additionally,a perovskite module with an aperture area of 21 cm^(2)achieved an efficiency of 22.28%,demonstrating the excellent scalability of the PyBA treatment.Moreover,the well-modified buried interface combined with the chemical inertness and structural rigidity of pyrene ensures excellent ultraviolet(UV)stability(the target module maintained 92%of the initial efficiency after 200 h and the control device only retained 40%).展开更多
基金Funded by the Scientific and Technologial Innovation Programs of Higher Education Institutions in Shanxi (No. 2020L0628)the Taiyuan Institute of Technology Scientific Research Initial Funding (No. 2022KJ072)+2 种基金the Program for the (Reserved) Discipline Leaders of Taiyuan Institute of Technologythe Fundamental Research Funds for the Central Universities (Nos. 2017TS004, 2017TS006, and GK201704005)Supported by HZWTECH for providing computational facilities
文摘In order to explore the effect of vacancy defects on the structural,electronic,magnetic and optical properties of CoS_(2) and FeS_(2),first-principles calculation method was used to investigate the alloys.The calculated results of materials without vacancy are consistent with those reported in the literatures,while the results of materials with vacancy defect were different from those of literatures due to the difference vacancy concentration.The Co vacancy defect hardly changes the half-metallic characteristic of CoS_(2).The Fe vacancy defect changes FeS_(2) from semiconductor to half-metal,and the bottom of the spin-down conduction band changes from the p orbital state of S to the d(t_(2g))orbital state of Fe,while the top of the valence band remains the d orbital d(eg)state of Fe.The half-metallic Co vacancy defects of CoS_(2) and Fe vacancy defects of FeS_(2) are expected to be used in spintronic devices.S vacancy defects make both CoS_(2) and FeS_(2) metallic.Both the Co and S vacancy defects lead to the decrease of the magnetic moment of CoS_(2),while both the Fe and S vacancy defects lead to the obvious magnetic property of FeS_(2).Vacancy defects enhance the absorption coefficient of infrared band and long band of visible light obviously,and produce obvious red shift phenomenon,which is expected to be used in photoelectric devices.
基金supported by grants from the Province Nature Science Foundation of Liaoning Province(Grant No.2019JH/30100019)。
文摘Improving brittle behavior and mechanical properties is still a big challenge for high-temperature structural materials.By means of first-principles calculations,in this paper,we systematically investigate the effect of vacancy and oxygen occupation on the elastic properties and brittle-or-ductile behavior on Mo_(5)Si_(3).Four vacancies(Si_(-Va1),Si_(-Va2),Mo_(-Va1),Mo_(-Va2))and oxygen occupation models(O_(Mo1),O_(Mo2),O_(-Si1),O_(-Si2))are selected for research.It is found that Mo_(-Va2) vacancy has the stronger structural stability in the ground state in comparison with other vacancies.Besides,the deformation resistance and hardness of the parent Mo_(5)Si_(3) are weakened due to the introduction of different vacancy defects and oxygen occupation.The ratio of B/G indicates that oxygen atoms occupation and vacancy defects result in brittle-to-ductile transition for Mo_(5)Si_(3).These vacancies and the oxygen atoms occupation change the localized hybridization between Mo-Si and Mo-Mo atoms.The weaker O-Mo bond is a contributing factor for the excellent ductile behavior in the O_(-Si2) model for Mo_(5)Si_(3).
基金supported by the Program for Changjiang Scholars and Innovative Research Team in the Universities of the Ministry of Education of China (No. IRT0520)
文摘The effects of vacancy defects on the thermal conductivity of Ge thin films were investigated by employing molecular dynamics （MD） simula- tions and theoretical analysis based on the Boltzmann equation. Both the MD and theoretical results show that the lattice thermal conductivity dramatically decreases with the increasing of vacancy concentration at 400 and 500 K. In addition, the dependence of vacancy concentration on the thermal conductivity of Ge thin films becomes less sensitive as the temperature increases. Theoretical results also confirm that the major part of the lattice thermal conductivity reduction is associated with the point-defect scattering and phonon-phonon scattering processes.
基金Project(50864001) supported by the National Natural Science Foundation of China
文摘The electronic properties of sphalerite(110) surface with Zn-vacancy and S-vacancy were calculated by using density-functional theory,and the effects of vacancy defect on the copper activation of sphalerite were investigated.The calculated results indicate that surface state occurs in the band gap of Zn-vacancy sphalerite,which is from the contribution of S 3p orbital at the first layer of the surface.The presence of S-vacancy results in surface state appearing near the Fermi level and the bottom of conductor band,which are composed of S 3p and Zn 4s orbital,respectively.The surface structure of Zn-vacancy sphalerite is more stable than S-vacancy surface due to the occupation of Zn-vacancy by Cu atoms;hence,the substitution reaction of Cu for Zn vacancy is easier than the substitution of Cu for Zn atoms with S-vacancy surface.
基金supported by the National Natural Science Foundation of China(NSFC 52002091,U22A20347,and 52102344)Heilongjiang Natural Science Foundation Project of Outstanding Youth Project(YQ2023B005)+1 种基金China Postdoctoral Science Foundation(2023T160154)the Fundamental Research Funds for the Central Universities。
文摘The therapeutic efficacy of cuproptosis,ferroptosis,and apoptosis is hindered by inadequate intracellular copper and iron levels,hypoxia,and elevated glutathione(GSH)expression in tumor cells.Thermoelectric technology is an emerging frontier in medical therapy that aims to achieve efficient thermal and electrical transport characteristics within a narrow thermal range for biological systems.Here,we systematically constructed biodegradable Cu_(2)MnS_(3-x)-PEG/glucose oxidase(MCPG)with sulfur vacancies(S_(V))using photothermoelectric catalysis(PTEC),photothermal-enhanced enzyme catalysis,and starvation therapy.This triggers GSH consumption and disrupts intracellular redox homeostasis,leading to immunogenic cell death.Under 1064 nm laser irradiation,MCPG enriched with S_(V),owing to doping,generates a local temperature gradient that activates PTEC and produces toxic reactive oxygen species(ROS).Hydroxyl radicals and oxygen are generated through peroxide and catalase-like processes.Increased oxygen levels alleviate tumor hypoxia,whereas hydrogen peroxide production from glycometabolism provides sufficient ROS for a cascade catalytic reaction,establishing a self-reinforcing positive mechanism.Density functional theory calculations demonstrated that vacancy defects effectively enhanced enzyme catalytic activity.Multimodal imaging-guided synergistic therapy not only damages tumor cells,but also elicits an antitumor immune response to inhibit tumor metastasis.This study offers novel insights into the cuproptosis/ferroptosis/apoptosis pathways of Cu-based PTEC nanozymes.
基金supported by the Research Project on Strengthening the Construction of an Important Ecological Security Barrier in Northern China by Higher Education Institutions in the Inner Mongolia Autonomous Region(STAQZX202313)the Inner Mongolia Autonomous Region Education Science‘14th Five-Year Plan’2024 Annual Research Project(NGJGH2024635).
文摘Vacancy defects,as fundamental disruptions in metallic lattices,play an important role in shaping the mechanical and electronic properties of aluminum crystals.However,the influence of vacancy position under coupled thermomechanical fields remains insufficiently understood.In this study,transmission and scanning electron microscopy were employed to observe dislocation structures and grain boundary heterogeneities in processed aluminum alloys,suggesting stress concentrations and microstructural inhomogeneities associated with vacancy accumulation.To complement these observations,first-principles calculations and molecular dynamics simulations were conducted for seven single-vacancy configurations in face-centered cubic aluminum.The stress response,total energy,density of states(DOS),and differential charge density were examined under varying compressive strain(ε=0–0.1)and temperature(0–600 K).The results indicate that face-centered vacancies tend to reduce mechanical strength and perturb electronic states near the Fermi level,whereas corner and edge vacancies appear to have weaker effects.Elevated temperatures may partially restore electronic uniformity through thermal excitation.Overall,these findings suggest that vacancy position exerts a critical but position-dependent influence on coupled structure-property relationships,offering theoretical insights and preliminary experimental support for defect-engineered aluminum alloy design.
基金supported by the National Key Research and Development Program of China(Nos.2020YFA0907300 and 2021YFB3501404)the National Natural Science Foundation of China(Nos.52301234,52371179,and 52071070)+1 种基金the Doctoral Start-up Foundation of Liaoning Province(No.2023-BS-059)the Fundamental Research Funds for the Central Universities(No.N2309002).
文摘L1_(0)-FePt nanoparticles(NPs)are urgently anticipated because of their promising applications.However,the preparation of the NPs with both of high ordering degree and super-fine size is still a challenge.Inspired by recent studies on the effect of vacancy defects on structural ordering,we proposed an intentional vacancy defect design strategy for directly synthesizing highly ordered FePt NPs.In the present work,we used the first-principle calculations to investigate the influence of doping typical elements(Cu,Ag,and Pb)on the vacancy formation energy(E_(vac))of FePt NPs.The vacancy defects were effectively formed by introducing elements of larger atomic radii and higher propensity for segregation into the FePt lattice,facilitating the diffusion of Fe and Pt atoms.The Pb doping showed remarkable efficacy in promoting the ordering transition.Experimentally,wet-chemical synthesis confirmed the success of the proposed strategy in achieving highly ordered L1_(0)-FePt NPs with exceptional magnetic properties and super-fine size(ordering degree of 0.896,impressive coercivity of 21.74 kOe,and small particle size of 9.02 nm).Additionally,we have deduced a diffusion model elucidating the formation process of the ordered FePt NPs,focusing on the migration of Pb atoms from the center to the surface of the particles.This migration is demonstrated to generate more vacancies and promote the transition to the ordered L1_(0)-FePt phase.The findings of this research offer valuable insights into synthesizing highly ordered and ultrafine L1_(0)-type nanomaterials.
基金supported by the National Natural Science Foundation of China(No.52002094)Shenzhen Science and Technology Program(Nos.JCYJ20210324121411031,JSGG202108021253804014 and RCBS20210706092218040)Shenzhen Steady Support Plan(Nos.GXWD20221030205923001 and GXWD20201230155427003-20200824103000001).
文摘Recently,high-entropy materials are attracting enormous attention in battery applications,encompassing both electrode materials and solid electrolytes,due to the pliability and diversification in material composition and electronic structure.Theoretically,the rapid ion transport and the abundance of surface defects in high-entropy materials suggest a potential for enhancing the performance of composite solid-state electrolytes(CPEs).Herein,using a high-entropy oxide(HEO)filler to assess its potential contributions to CPEs is proposed.The distinctive structural distortions in HEO significantly improve the ionic conductivity(5×10^(−4) S·cm^(−1) at 60℃)and Li-ion transference number(0.57)of CPEs.Furthermore,the enhanced Li-ion transport capability extends the critical current density from 0.6 to 1.5 mA·cm^(−2) in Li/Li symmetric cells.In addition,all-solid-state batteries incorporating the HEO-modified CPEs exhibit superior rate performance and cycling stability.The work will enrich the application of HEOs in CPEs and provide fundamental understanding.
基金supported by the National Natural Science Foundation of China,China(Grant No.51932010)by the National Natural Science Foundation of Shanghai,China(Grant No.19ZR1464600).
文摘Bismuth titanate (Bi_(4)Ti_(3)O_(12),BIT)piezoelectric materials have attracted increasing attention due to their high-temperature applications.However,it is quite challenging to simultaneously achieve outstanding piezoelectric properties and high Curie temperature in BIT-based systems.In this study,oxygen vacancy defects tailoring strategy was utilized to solve this problem,excellent piezoelectric coefficient(32.1 pC/N),and ultrahigh Curie temperature(659℃)are gotten in Bi_(4)Ti_(3)-x(Mn_(1/3)Nb_(2/3))xO_(12)(BTMN)ceramics,which are among the top values in the BIT-based ceramics.More importantly,the(Mn_(1/3)Nb_(2/3))(4+d)+complex-ion modified Bi_(4)Ti_(3)O_(12)-based ceramics are characterized with excellent piezoelectric stability up to 500℃(d33>30.0 pC/N at 500℃))and significantly reduced conductivity(only~10^(-7)U-1 cm^(-1)at 500℃).Moreover,enhanced ferroelectricity and good dielectric stability were also obtained.The better comprehensive properties can be ascribed to two aspects.First,the concentration of oxygen vacancy defects is obviously reduced,and their distribution is effectively controlled in BITMN ceramics.Second,the introduction of(Mn_(1/3)Nb_(2/3))^((4+δ)+)complex-ion gives rise to the antiphase boundaries and massive ferroelectric domain walls.This works not only reveal the high potential of BITMN ceramics for high-temperature piezoelectric applications but also deepen the understanding of the structure-properties relationship in BIT-based materials.
基金supported by the National Natural Science Foundation of China(52072196)the Major Basic Research Program of the Natural Science Foundation of Shandong Province(ZR2020ZD09)。
文摘MoS_(2)is a promising electrocatalyst because of its natural abundance and outstanding electrochemical stability.However,the poor conductivity and low activity limit its catalytic performance;furthermore,MoS_(2)is unable to satisfy the requirements of most industrial applications.In this study,to obtain a P-doped MoS_(2)catalyst with S vacancy defects,P is inserted into the MoS_(2)matrix via a solid phase ion exchange at room temperature.The optimal P-doping amount is 11.4 wt%,and the resultant catalyst delivers excellent electrocatalytic properties for the hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)with the corresponding overpotentials of 93 and 316 mV at 10 mA cm^(-2) in an alkaline solution;these values surpass the overpotentials of most previously reported MoS_(2)-based materials.Theoretical calculations and results demonstrate that the synergistic effect of the doped P,which forms active centers in the basal plane of MoS_(2),and S vacancy defects caused by P doping intensifies the intrinsic electronic conductivity and electrocatalytic activity of the catalyst.Density functional theory calculations demonstrate that P optimizes the free energy of the MoS_(2)matrix for hydrogen adsorption,thereby considerably increasing the intrinsic activity of the doped catalyst for the HER compared with that observed from pristine MoS_(2).The enhanced catalytic activity of P-doped MoS_(2)for the OER is attributed to the ability of the doped P which facilitates the adsorption of hydroxyl and hydroperoxy intermediates and reduces the reaction energy barrier.This study provides a new environmentally friendly and convenient solid-phase ion exchange method to improve the electrocatalytic capability of two-dimensional transition-metal dichalcogenides in largescale applications.
基金supports from the National Key Research and Development Program of China(No.2020YFB1505703)This work was supported by the National Natural Science Foundation of China(Nos.52172299,22175198,51772319,51772320,and 51972331)+3 种基金Z.G.Z would like to acknowledge the support from the External Cooperation Program of the Chinese Academy of Sciences(No.121E32KYSB20190008)Six Talent Peaks Project of Jiangsu Province(No.XCL-170)S.C would like to acknowledge the support from the Youth Innovation Promotion Association,CAS(No.2018356)the Outstanding Youth Fund of Jiangxi(No.20192BCBL23027).
文摘Photo-induced vacancy defects are employed strategically to imbue semiconductors with enhanced performance characteristics for many important applications such as surface-enhanced Raman scattering(SERS)sensing,photocatalysis,and photovoltaic applications.However,the long-term maintenance and use of photo-induced vacancy defects remain elusive,because of their rapid self-healing upon air exposure.In this study,we demonstrate that photo-induced oxygen vacancy(PIVO)defects can be stabilized by the photoexcitation of metal–organic framework(MOF)materials,which is crucial for SERS analysis.The PIVO defects in MOF materials are stable for at least two weeks in the ambient atmosphere,owing to the combination of steric hindrance and electron delocalization around vacancy defects,which significantly contrasts the short lifetime(within minutes)of PIVO defects in metal-oxide semiconductors.With the formation of stable PIVO defects,a prominent SERS enhancement surpassing that of pristine MOFs is achieved,accompanied with a reduced limit of detection by three orders of magnitude.Moreover,the additional SERS enhancement rendered by PIVO defects can be stably retained and is effective for monitoring various small molecules,such as dopamine and bisphenol A.
基金Project supported by the Industry and Education Combination Innovation Platform of Intelligent Manufacturing and Graduate Joint Training Base at Guizhou University(Grant No.2020-520000-83-01-324061)the National Natural Science Foundation of China(Grant No.61264004)the High-level Creative Talent Training Program in Guizhou Province of China(Grant No.[2015]4015).
文摘Recently,the newly synthesized septuple-atomic layer two-dimensional(2D)material MoSi_(2)N_(4)(MSN)has attracted attention worldwide.Our work delves into the effect of vacancies and external electric fields on the electronic properties of the MSN/graphene(Gr)heterostructure using first-principles calculation.We find that four types of defective structures,N-in,N-out,Si and Mo vacancy defects of monolayer MSN and MSN/Gr heterostructure are stable in air.Moreover,vacancy defects can effectively modulate the charge transfer at the interface of the MSN/Gr heterostructure as well as the work function of the pristine monolayer MSN and MSN/Gr heterostructure.Finally,the application of an external electric field enables the dynamic switching between n-type and p-type Schottky contacts.Our work may offer the possibility of exceeding the capabilities of conventional Schottky diodes based on MSN/Gr heterostructures.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61204008,11075176,and 11505211)the National Key Basic Research Special Foundation of China(Grant No.2013CB328705)
文摘Role of vacancy-type（N vacancy（VN） and Ga vacancy（VGa）） defects in magnetism of GaMnN is investigated by first-principle calculation.Theoretical results show that both the VNand VGainfluence the ferromagnetic state of a system.The VNcan induce antiferromagnetic state and the VGaindirectly modify the stability of the ferromagnetic state by depopulating the Mn levels in GaMnN.The transfer of electrons between the vacancy defects and Mn ions results in converting Mn3＋（d4） into Mn2＋（d5）.The introduced VNand the ferromagnetism become stronger and then gradually weaker with Mn concentration increasing,as well as the coexistence of Mn3＋（d4） and Mn2＋（d5） are found in GaMnN films grown by metal–organic chemical vapor deposition.The analysis suggests that a big proportion of Mn3＋changing into Mn2＋will reduce the exchange interaction and magnetic correlation of Mn atoms and lead to the reduction of ferromagnetism of material.
文摘The Young＇s modulus of graphene with various rectangular and circular vacancy defects is investigated by molecular dynamics simulation. By comparing with the results calculated from an effective spring model, it is demonstrated that the Young＇s modulus of graphene is largely correlated to the size of vacancy defects perpendicular to the stretching direction. And a linear reduction of Young＇s modulus with the increasing concentration of monoatomic-vacancy defects （Le., the slope of =0.03） is also observed. The fracture behavior of graphene, including the fracture strength, crack initiation and propagation are then studied by the molecular dynamics simulation, the effective spring model, and the quantized fracture mechanics. The blunting effect of vacancy edges is demonstrated, and the characterized crack tip radius of 4.44 A is observed.
基金financed by the National Key Research and Development Program of China(Grant No.2021YFB3802400)the National Natural Science Foundation of China(Grants Nos.52071141,52271212,52201250,and 51771056)+1 种基金the Natural Science Foundation of Hebei Province(Grant No.E2018502054)the Fundamental Research Funds for the Central Universities(Grant No.2023MS148).
文摘The vacancy defect exhibits a remarkable improvement in the dehydriding property of MgH_(2)@Ni-CNTs.However,the corresponding mechanism is still not fully understood.Herein,the impact of vacancy defects on the dehydrogenation properties of MgH_(2)@Ni-CNTs was studied by DFT simulation,and the corresponding models were constructed based on MS.The dehydrogenation process of MgH_(2)can be regarded as the dissociation of Mg-H and desorption of H_(2)from the MgH_(2)surface.In view of the whole dehydrogenation,the dissociation of H^(−)is the rate-determining step,which is the main reason for restricting the dehydrogenation kinetics.Compared with vacancy vacancy-defective MgH_(2)(001)surface,the appearance of vacancy defects on the(110)surface substantially reduces the energy barrier required for H dissociation to 0.070 Ha.The reason is that vacancy defects accelerate the transition of electrons from the H^(−)s orbit to the Mg^(2+)3s orbit,resulting in a decrement of the Mg-H bond strength,which makes H atoms more easily dissociated from the MgH_(2)(110)surface.Therefore,the existence of vacancy defects improves the dehydriding kinetic of MgH_(2).Most importantly,this research offers crucial directions for developing hydrogen storage materials as well as a potential fix for the slow dehydrogenation kinetics of nano-confined MgH_(2).
基金Project supported by the China Postdoctoral Science Foundation(No.201104619)the Fund of Shaanxi Provincial Educational Department (No.2010JK775)
文摘Based on first-principle calculations, the electronic structures and optical properties of a single-walled （7, 0） SiC nanotube （SiCNT） with a carbon vacancy defect or a silicon vacancy defect are investigated. In the three silicon atoms around the carbon vacancy, two atoms form a stable bond and the other is a dangling bond. A similar structure is found in the nanotube with a silicon vacancy. A carbon vacancy results in a defect level near the top of the valence band, while a silicon vacancy leads to the formation of three defect levels in the band gap of the nanotube. Transitions between defect levels and energy levels near the bottom of the conduction band have a close relationship with the formation of the novel dielectric peaks in the lower energy range of the dielectric function.
基金supported by the National Natural Science Foundation of China(62474043,62074037,52372183)the Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(2021ZZ124)+1 种基金Fujian Provincial Natural Science Foundation of China(2024J09015)the Foundation of Fujian Provincial Department of Industry and Information Technology of China(82318075)。
文摘High performances of Cu_(2)ZnSn(S,Se)_(4)(CZTSSe)solar cells are heavily influenced by the quality of heterojunctions.Herein,an oxygen(O)doping of CZTSSe/CdS heterojunction is performed to suppress the formation of the defects by an ultraviolet ozone(UV-O_(3))treatment for the efficient flexible CZTSSe solar cells.The introduction of O reduces the non-radiative recombination and increases the carrier concentration of the CdS films.Furthermore,the defect density of the CdS film has been reduced from 8.24×10^(16)to2.91×10^(16)cm^(-3)by the O-doping.The results indicate that the electron transport is effectively promoted due to the decreased conduction band offset(CBO)at the heterojunction interface.As a result,the champion flexible CZTSSe solar cell achieves a power conversion efficiency(PCE)of 11.21%,with a significantly improved short circuit current density.The study for improving the CZTSSe/CdS heterojunction through O-doping treatment provides a new insight for enhancing the PCE of the flexible CZTSSe solar cells.
基金supported by the National Natural Science Foundation of China(52172239)Project of State Key Laboratory of Environment-Friendly Energy Materials+2 种基金Southwest University of Science and Technology(Grant Nos.21fksy24 and 18ZD320304)Chongqing Talents:Exceptional Young Talents Project(Grant No.CQYC201905041)Natural Science Foundation of Chongqing China(Grant No.cstc2021jcyj-jqX0031)。
文摘The defect chemistry is successfully modulated on free-standing and binder-free carbon cathodes for highly efficient Li-S redox reactions.Such rationally regulated defect engineering realizes the synchronization of ion/electron-conductive and defect-rich networks on the threedimension carbon cathode,leading to its tunable activity for both relieving the shuttle phenomenon and accelerating the sulfur redox reaction kinetics.As expected,the defective carbon cathode harvests a high rate capacity of 1217.8 mAh g^(-1)at 0.2 C and a superior capacity retention of61.7%at 2 C after 500 cycles.Even under the sulfur mass loading of 11.1 mg cm^(-2),the defective cathode still holds a remarkable areal capacity of 8.5 mAh cm^(-2).
基金supported by the National Natural Science Foundation of China (21107124, 21337003)the Youth Innovation Promotion Association (2011037)Science Promotion Program of Research Center for Eco-Environmental Sciences, Chinese Academic Sciences (No. 121311RCEES-QN-20130046F)
文摘We describe here a one-step method for the synthesis of Au/TiO2 nanosphere materials,which were formed by layered deposition of multiple anatase TiO2 nanosheets.The Au nanoparticles were stabilized by structural defects in each TiO2 nanosheet,including crystal steps and edges,thereby fixing the Au-TiO2 perimeter interface.Reactant transfer occurred along the gaps between these TiO2 nanosheet layers and in contact with catalytically active sites at the Au-TiO2 interface.The doped Au induced the formation of oxygen vacancies in the Au-TiO2 interface.Such vacancies are essential for generating active oxygen species（-＊O^-） on the TiO2 surface and Ti^3＋ ions in bulk TiO2.These ions can then form Ti^3＋-O^--Ti^4＋species,which are known to enhance the catalytic activity of formaldehyde（HCHO） oxidation.These studies on structural and oxygen vacancy defects in Au/TiO2 samples provide a theoretical foundation for the catalytic mechanism of HCHO oxidation on oxide-supported Au materials.
基金Y.Zhan acknowledges funding support from the National Key Research and Development Program of China(2022YFE0137400)the National Natural Science Foundation of China(62274040)+5 种基金A.Yu acknowledges funding support from the National Natural Science Foundation of China(62304046)the National Key Research and Development Program of China(2022YFB2802802)the Key Laboratory of Rare Earths,Ganjiang Innovation Academy,Chinese Academy of SciencesX.Zhang acknowledges funding from the China Postdoctoral Science Foundation(GZC20230463)X.Li acknowledges funding from the China Postdoctoral Science Foundation(GZC20230461)We also acknowledge support from the Shanghai Science and Technology Innovation Action Plan 2023 Special Project for Supporting Carbon Peak Carbon Neutrality Project(23DZ1200400).
文摘The NiOx,due to its excellent semiconductor properties,ease of large-area deposition,and tunable optoelectronic characteristics,shows great potential in industrial large-area perovskite technologies.However,NiO_(x)-based perovskite solar cells(PSCs)are limited by interfacial photocatalytic chemical reactions and energy level mismatch.Thus,phosphate-based self-assembled monolayers(SAMs)have been widely developed for delicate interfacial modification;however,they suffer from severe issues such as self-aggregation and high cost.Herein,a low-cost carboxylate-based SAM(pyrenebutyric acid,PyBA)was used to modify NiO_(x),achieving an improved surface chemical environment and interfacial properties,such as an increased Ni^(3+)/Ni2^(+)ratio,a reduced proportion of high-valence Ni^(≥3+),and better-aligned hole transport interface energy level.The introduction of PyBA also results in larger grain size,higher uniformity,and enhanced photoluminescence(PL)from the bottom of the perovskite,yielding a significant increase in efficiency from an initial 22.48%to 25.14%,while increasing the open-circuit voltage(VOC)from 1.077 to 1.192 V.Additionally,a perovskite module with an aperture area of 21 cm^(2)achieved an efficiency of 22.28%,demonstrating the excellent scalability of the PyBA treatment.Moreover,the well-modified buried interface combined with the chemical inertness and structural rigidity of pyrene ensures excellent ultraviolet(UV)stability(the target module maintained 92%of the initial efficiency after 200 h and the control device only retained 40%).
