Compared to the well-studied two-dimensional(2D)ferroelectricity,the appearance of 2D antiferroelectricity is much rarer,where local dipoles from the nonequivalent sublattices within 2D monolayers are oppositely orien...Compared to the well-studied two-dimensional(2D)ferroelectricity,the appearance of 2D antiferroelectricity is much rarer,where local dipoles from the nonequivalent sublattices within 2D monolayers are oppositely oriented.Using NbOCl_(2) monolayer with competing ferroelectric(FE)and antiferroelectric(AFE)phases as a 2D material platform,we demonstrate the emergence of intrinsic antiferroelectricity in NbOCl_(2) monolayer under experimentally accessible shear strain,along with new functionality associated with electric field-induced AFE-to-FE phase transition.Specifically,the complex configuration space accommodating FE and AFE phases,polarization switching kinetics,and finite temperature thermodynamic properties of 2D NbOCl_(2) are all accurately predicted by large-scale molecular dynamics simulations based on deep learning interatomic potential model.Moreover,room temperature stable antiferroelectricity with low polarization switching barrier and one-dimensional collinear polarization arrangement is predicted in shear-deformed NbOCl_(2) monolayer.The transition from AFE to FE phase in 2D NbOCl_(2) can be triggered by a low critical electric field,leading to a double polarization–electric(P–E)loop with small hysteresis.A new type of optoelectronic device composed of AFE-NbOCl_(2) is proposed,enabling electric“writing”and nonlinear optical“reading”logical operation with fast operation speed and low power consumption.展开更多
Electron–hole(e–h)recombination is a fundamental process that governs energy dissipation and device efficiency in semiconductors.In two-dimensional(2D)materials,the formation of tightly bound excitons makes exciton-...Electron–hole(e–h)recombination is a fundamental process that governs energy dissipation and device efficiency in semiconductors.In two-dimensional(2D)materials,the formation of tightly bound excitons makes exciton-mediated e–h recombination the dominant decay pathway.In this work,nonradiative e–h recombination within excitons in monolayer MoS2 is investigated using first-principles simulations that combine nonadiabatic molecular dynamics with𝐺𝑊and real-time Bethe–Salpeter equation(BSE)propagation.A two-step process is identified:rapid intervalley redistribution induced by exchange interaction,followed by slower phonon-assisted recombination facilitated by exciton binding.By selectively removing the screened Coulomb and exchange terms from the BSE Hamiltonian,their respective contributions are disentangled—exchange interaction is found to increase the number of accessible recombination pathways,while binding reduces the excitation energy and enhances nonradiative decay.A reduction in recombination lifetime by over an order of magnitude is observed due to the excitonic many-body effects.These findings provide microscopic insights for understanding and tuning exciton lifetimes in 2D transition-metal dichalcogenides.展开更多
The stable nanobubbles adhered to mineral surfaces may facilitate their efficient separation via flotation in the mining industry.However,the state of nanobubbles on mineral solid surfaces is still elusive.In this stu...The stable nanobubbles adhered to mineral surfaces may facilitate their efficient separation via flotation in the mining industry.However,the state of nanobubbles on mineral solid surfaces is still elusive.In this study,molecular dynamics(MD)simulations are employed to examine mineral-like model surfaces with varying degrees of hydrophobicity,modulated by surface charges,to elucidate the adsorption behavior of nanobubbles at the interface.Our findings not only contribute to the fundamental understanding of nanobubbles but also have potential applications in the mining industry.We observed that as the surface charge increases,the contact angle of the nanobubbles increases accordingly with shape transformation from a pancake-like gas film to a cap-like shape,and ultimately forming a stable nanobubble upon an ordered water monolayer.When the solid–water interactions are weak with a small partial charge,the hydrophobic gas(N_(2))molecules accumulate near the solid surfaces.However,we have found,for the first time,that gas molecules assemble a nanobubble on the water monolayer adjacent to the solid surfaces with large partial charges.Such phenomena are attributed to the formation of a hydrophobic water monolayer with a hydrogen bond network structure near the surface.展开更多
High-resolution transmission electron microscopy(HRTEM)promises rapid atomic-scale dynamic structure imaging.Yet,the precision limitations of aberration parameters and the challenge of eliminating aberrations in Cs-co...High-resolution transmission electron microscopy(HRTEM)promises rapid atomic-scale dynamic structure imaging.Yet,the precision limitations of aberration parameters and the challenge of eliminating aberrations in Cs-corrected transmission electron microscopy constrain resolution.A machine learning algorithm is developed to determine the aberration parameters with higher precision from small,lattice-periodic crystal images.The proposed algorithm is then validated with simulated HRTEM images of graphene and applied to the experimental images of a molybdenum disulfide(MoS_(2))monolayer with 25 variables(14 aberrations)resolved in wide ranges.Using these measured parameters,the phases of the exit-wave functions are reconstructed for each image in a focal series of MoS_(2)monolayers.The images were acquired due to the unexpected movement of the specimen holder.Four-dimensional data extraction reveals time-varying atomic structures and ripple.In particular,the atomic evolution of the sulfur-vacancy point and line defects,as well as the edge structure near the amorphous,is visualized as the resolution has been improved from about 1.75?to 0.9 A.This method can help salvage important transmission electron microscope images and is beneficial for the images obtained from electron microscopes with average stability.展开更多
Multiferroic tunnel junctions(MFTJs),which combine tunneling magnetoresistance(TMR)and electroresistance(TER)efects,have emerged as key candidates for data storage.Two-dimensional van der Waals(vdW)MFTJs,in particular...Multiferroic tunnel junctions(MFTJs),which combine tunneling magnetoresistance(TMR)and electroresistance(TER)efects,have emerged as key candidates for data storage.Two-dimensional van der Waals(vdW)MFTJs,in particular,are promising spintronic devices for the post-Moore era.However,these vdW MFTJs are typically based on multiferroics composed of ferromagnetic and ferroelectric materials or multilayer magnetic materials with sliding ferroelectricity,which increases device fabrication complexity.In this work,we design a vdW MFTJ using bilayer MoPtGe_(2)S_(6),a material with homologous multiferroicity in each monolayer,combined with symmetric PtTe_(2)electrodes.Using frst-principles calculations based on density functional theory and nonequilibrium Green's functions,we theoretically explore the spin-polarized electronic transport properties of this MFTJ.By controlling the ferroelectric and ferromagnetic polarization directions of bilayer MoPtGe_(2)S_(6),the MFTJ can exhibit six distinct non-volatile resistance states,with maximum TMR(137%)and TER(1943%)ratios.Under biaxial strain,TMR and TER can increase to 265%and 4210%,respectively.The TER ratio also increases to 2186%under a 0.1 V bias voltage.Remarkably,the MFTJ exhibits a pronounced spin-fltering and a signifcant negative diferential resistance efect.These fndings not only highlight the potential of monolayer multiferroic MoPtGe_(2)S_(6)for MFTJs but also ofer valuable theoretical insights for future experimental investigations.展开更多
A redox-active monolayer on an optically transparent electrode constitutes a typical platform for spectroelectrochemical sensing.The necessity for its sophistication arises from the availability of multi-dimensional s...A redox-active monolayer on an optically transparent electrode constitutes a typical platform for spectroelectrochemical sensing.The necessity for its sophistication arises from the availability of multi-dimensional sensing signals.Simultaneous monitoring of the redox current and color change synchronized with the oxidation state change significantly enhances sen-sitivity and selectivity.This study aimed to elucidate the modification of an indium tin oxide(ITO)electrode with a viologen monolayer with an ordered orientation.Novel methods were developed to immobilize a viologen molecule bearing a car-boxyl group to form assembled monolayers through a condensation reaction using 1-ethyl-3-(3-dimethylaminopropyl)-car-bodiimide with N-hydroxy-succinimide(EDC/NHS).In the two methods of immobilization,one utilizes a two-step process to firstly form an aromatic siloxane base layer and subsequently attach the viologen derivative through an amide linkage by post-amidation.The other employs a direct ester linkage between the hydroxyl groups of the ITO surface and the car-boxyl group of the viologen derivative.The latter method was also applied to immobilize a ferrocenyl group at a very short distance from the ITO surface.Potential-modulated UV-visible transmission absorption spectral measurement techniques with oblique incidence of plane-polarized light were employed to determine the orientation of the longitudinal axis of the reduced form of the viologen.The frequency dependence data of the potential-modulated transmission absorption signals were utilized to analyze the electron transfer kinetics.The performance of the two viologen-modified electrodes was com-pared to that of an ITO modified by post-amidation to the most commonly used base layer prepared with 3-aminopropyl triethoxysilane.展开更多
Ferromagnetic materials play an important role in memory materials,but conventional control methods are often limited by issues such as high power consumption and volatility.Multiferroic heterostructures provide a pro...Ferromagnetic materials play an important role in memory materials,but conventional control methods are often limited by issues such as high power consumption and volatility.Multiferroic heterostructures provide a promising alternative to achieve low power consumption and nonvolatile electric control of magnetic properties.In this paper,a two-dimensional multiferroic van der Waals heterostructure OsCl_(2)/Sc_(2)CO_(2),which is composed of ferromagnetic monolayer OsCl_(2)and ferroelectric monolayer Sc_(2)CO_(2),is studied by first-principles density functional theory.The results show that by reversing the direction of the electric polarization of Sc_(2)CO_(2),OsCl_(2)can be transformed from a semiconductor to a half-metal,demonstrating a nonvolatile electrical manipulation of the heterostructure through ferroelectric polarization.The underlying physical mechanism is explained by band alignments and charge density differences.Furthermore,based on the heterostructure,we construct a multiferroic tunnel junction with a tunnel electroresistance ratio of 3.38×10^(14)%and a tunnel magnetoresistance ratio of 5.04×10^(6)%,allowing control of conduction states via instantaneous electric or magnetic fields.The findings provide a feasible strategy for designing advanced nanodevices based on the giant tunnel electroresistance and tunnel magnetoresistance effects.展开更多
The labels of VU1 and VU2 in Fig.1(b)of the paper[Chin.Phys.B 34046801(2025)]were not correctly placed.The correct figure is provided.This modification does not affect the result presented in the paper.
Two dimensional(2D) materials based on boron and carbon have attracted wide attention due to their unique properties. BC compounds have rich active sites and diverse chemical coordination, showing great potential in o...Two dimensional(2D) materials based on boron and carbon have attracted wide attention due to their unique properties. BC compounds have rich active sites and diverse chemical coordination, showing great potential in optoelectronic applications. However, due to the limitation of calculation and experimental conditions, it is still a challenging task to predict new 2D BC monolayer materials. Specifically, we utilized Crystal Diffusion Variational Autoencoder(CDVAE) and pre-trained Materials Graph Neural Network with 3-Body Interactions(M3GNet) model to generate novel and stable BCP materials. Each crystal structure was treated as a high-dimensional vector, where the encoder extracted lattice information and element coordinates, mapping the high-dimensional data into a low-dimensional latent space. The decoder then reconstructed the latent representation back into the original data space. Additionally, our designed attribute predictor network combined the advantages of dilated convolutions and residual connections,effectively increasing the model's receptive field and learning capacity while maintaining relatively low parameter count and computational complexity. By progressively increasing the dilation rate, the model can capture features at different scales. We used the DFT data set of about 1600 BCP monolayer materials to train the diffusion model, and combined with the pre-trained M3GNet model to screen the best candidate structure. Finally, we used DFT calculations to confirm the stability of the candidate structure.The results show that the combination of generative deep learning model and attribute prediction model can help accelerate the discovery and research of new 2D materials, and provide effective methods for exploring the inverse design of new two-dimensional materials.展开更多
Self-assembled monolayers(SAMs)are widely used as hole transport materials in inverted perovskite solar cells,offering low parasitic absorption and suitability for semitransparent and tandem solar cells.While SAMs hav...Self-assembled monolayers(SAMs)are widely used as hole transport materials in inverted perovskite solar cells,offering low parasitic absorption and suitability for semitransparent and tandem solar cells.While SAMs have shown to be promising in small-area devices(≤1 cm^(2)),their application in larger areas has been limited by a lack of knowledge regarding alternative deposition methods beyond the common spin-coating approach.Here,we compare spin-coating and upscalable methods such as thermal evaporation and spray-coating for[2-(9H-carbazol-9-yl)ethyl]phosphonic acid(2PACz),one of the most common carbazole-based SAMs.The impact of these deposition methods on the device performance is investigated,revealing that the spray-coating technique yields higher device performance.Furthermore,our work provides guidelines for the deposition of SAM materials for the fabrication of perovskite solar modules.In addition,we provide an extensive characterization of 2PACz films focusing on thermal evaporation and spray-coating methods,which allow for thicker 2PACz deposition.It is found that the optimal 2PACz deposition conditions corresponding to the highest device performances do not always correlate with the monolayer characteristics.展开更多
Semiconductor colloidal quantum wells(CQWs)with atomic-precision layer thickness are rapidly gaining attention for next-generation optoelectronic applications due to their tunable optical and electronic properties.In ...Semiconductor colloidal quantum wells(CQWs)with atomic-precision layer thickness are rapidly gaining attention for next-generation optoelectronic applications due to their tunable optical and electronic properties.In this study,we investigate the dielectric and optical characteristics of CdSe CQWs with monolayer numbers ranging from 2 to 7,synthesized via thermal injection and atomic layer(c-ALD)deposition techniques.Through a combination of spectroscopic ellipsometry(SE)and first-principles calculations,we demonstrate the significant tunability of the bandgap,refractive index,and extinction coefficient,driven by quantum confinement effects.Our results show a decrease in bandgap from 3.1 to 2.0 eV as the layer thickness increases.Furthermore,by employing a detailed analysis of the absorption spectra,accounting for exciton localization and asymmetric broadening,we precisely capture the relationship between monolayer number and exciton binding energy.These findings offer crucial insights for optimizing CdSe CQWs in optoelectronic device design by leveraging their layer-dependent properties.展开更多
The dual quantum spin Hall insulator(QSHI)is a newly discovered topological state in the two-dimensional(2D)material TaIrTe_(4),which exhibits both a traditional Z_(2)band gap at the charge neutrality point and a Van ...The dual quantum spin Hall insulator(QSHI)is a newly discovered topological state in the two-dimensional(2D)material TaIrTe_(4),which exhibits both a traditional Z_(2)band gap at the charge neutrality point and a Van Hove singularity(VHS)that induces a correlated Z_(2)band gap with weak doping.Inspired by the recent progress in theoretical understanding and experimental measurements,a promising dual QSHI is predicted in the counterpart material of the NbIrTe_(4)monolayer by first-principles calculations.In addition to the well-known band inversion at the charge neutrality point,two new band inversions are found after a charge density wave(CDW)phase transition when the chemical potential is near the VHS:one direct and one indirect Z_(2)band gap.The VHSinduced non-trivial band gap is approximately 10 meV,significantly larger than that of TaIrTe_(4).Furthermore,as the newly generated band gap is mainly dominated by the 4d orbitals of Nb,the electronic correlation effects should be stronger for NbIrTe_(4)than for TaIrTe_(4).Therefore,the dual QSHI state in the NbIrTe_(4)monolayer is expected to provide a strong platform for investigating the interplay between topologies and correlation effects.展开更多
Monolayer CrI_(3),crystalizing in the P31m space group,is a prototypical two-dimensional(2D)material for observing intrinsic ferromagnetic order.However,its relatively low Curie temperature(T_(C))of 45 K severely limi...Monolayer CrI_(3),crystalizing in the P31m space group,is a prototypical two-dimensional(2D)material for observing intrinsic ferromagnetic order.However,its relatively low Curie temperature(T_(C))of 45 K severely limits its practical applications,highlighting the need to explore novel metastable polymorphs with enhanced magnetic properties.In this study,we employ a global crystal structure search technique combined with first-principles calculations to systematically investigate new monolayer CrI_(3)phases.Our structural predictions identify two novel polymorphs with Cm and P2/m space groups,both of which are dynamically stable and exhibit significantly higher T_(C)values of 145 K and 81 K,respectively.Electronic property calculations show that the Cm phase is a half-metal,while the P2/m phase is semiconducting with a bandgap of 0.14 eV.Monte Carlo simulations attribute these enhanced T_(C)values to a notable increase in exchange interactions.These findings expand the known phase space of CrI_(3)and provide a promising pathway for designing hightemperature 2D ferromagnets for next-generation spintronic applications.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
The optimization of hole transport layer(HTL)is crucial for achieving high efficiency and stability in inverted perovskite solar cells(PSCs)due to its role in facilitating hole transport and passivating the perovskite...The optimization of hole transport layer(HTL)is crucial for achieving high efficiency and stability in inverted perovskite solar cells(PSCs)due to its role in facilitating hole transport and passivating the perovskite bottom interface.While self-assembled monolayers(SAMs)are commonly used for this purpose,the inherent limitations of a single SAM,such as fixed energy levels and rigid structure,restrict their adaptability for different perovskite components and further efficiency enhancement.Here,we demonstrate a stepwise deposition method for SAM-based HTLs to address this issue.We regulated the energy level gradient by depositing two SAMs with distinct energy levels,while the interactions between the phosphate groups in the SAMs and perovskite effectively reduce defect density at the bottom interface of the perovskite film.The as-fabricated PSCs achieved enhanced efficiency and stability with PCEs of 25.7% and 24.0% for rigid and flexible PSCs,respectively;these devices maintain 90% of their initial PCE after 500 h of maximum power point tracking,and retain 98% of their initial PCE after 4,000 bending cycles,representing one of the most stable flexible PSCs reported to date.展开更多
Exploring earth-abundant,highly active bifunctional electrocatalysts for efficient hydrogen and oxygen evolution is crucial for water splitting.However,due to their distinct free energies and conducting behaviors(elec...Exploring earth-abundant,highly active bifunctional electrocatalysts for efficient hydrogen and oxygen evolution is crucial for water splitting.However,due to their distinct free energies and conducting behaviors(electron/hole),balancing the catalytic efficiency between hydrogen and oxygen evolution remains challenging for achieving bifunctional electrocatalysts.Here,we report a locally-doped MoS_(2)monolayer with an in-plane heterostructure acting as a bifunctional electrocatalyst and apply it to the overall water splitting.In this heterostructure,the core region contains Mo/S vacancies,while the ring region was doped by Fe atoms(in two substitution configurations:1FeMo and 3FeMo-VS clusters)with a p-type conductive characteristic.Our micro-cell measurements,combined with density functional theory(DFT)calculations,reveal that the vacancies-rich core region presents remarkable hydrogen evolution reaction(HER)activity while the Fe-doped ring gives an excellent oxygen evolution reaction(OER)activity,thus forming an in-plane bifunctional electrocatalyst.Finally,as a proof-of-concept for overall water splitting,we constructed a full-cell configuration based on a locally-doped MoS_(2)monolayer,which achieved a cell voltage of 1.87 V at 10 mA·cm^(-2),demonstrating outstanding performance in strong acid electrolytes.Our work provides insight into the hetero-integration of bifunctional electrocatalysts at the atomic level,paving the way for designing transition metal dichalcogenide catalysts with activity-manipulated regions capable of multiple reactions.展开更多
Inverted p-i-n perovskite solar cells(PSCs)based on self-assembled monolayers(SAMs)as hole-selective layers(HSLs)have produced potential record efficiencies of more than 26%by tuning work function,dipole,and passivati...Inverted p-i-n perovskite solar cells(PSCs)based on self-assembled monolayers(SAMs)as hole-selective layers(HSLs)have produced potential record efficiencies of more than 26%by tuning work function,dipole,and passivation defects.However,the stability of the SAM molecules,the stability of the molecular anchoring conformation,and the impact on the stability of subsequent PSCs have not been clearly elucidated.In this review,we systematically discussed the intrinsic connection between the molecular conformation(including anchoring groups,spacer groups,and terminal groups)and the stability of SAMs.Sequentially,the research progress of SAMs as HSLs in improving the stability of PSCs is summarized,including photostability,thermal stability,ion migration,and residual stress.Finally,we look forward to the shortcomings and possible challenges of using SAMs as HSLs for inverted PSCs.展开更多
Insight into exciton dynamics of two-dimensional(2D)transition metal dichalcogenides(TMDs)is critical for the optimization of their performance in photonic and optoelectronic devices.Although current researches have p...Insight into exciton dynamics of two-dimensional(2D)transition metal dichalcogenides(TMDs)is critical for the optimization of their performance in photonic and optoelectronic devices.Although current researches have primarily concentrated on the near-resonant excitation scenario in 2D TMDs,the case of excitation energies resonating with highenergy excitons or higher energies has yet to be fully elucidated.Here,a comparative analysis is conducted between highenergy excitation(360 nm)and near-resonant excitation(515 nm)utilizing transient absorption spectroscopy to achieve a comprehensive understanding of the exciton dynamics within monolayer WS_(2).It is observed that the high-energy C-exciton can be generated via an up-conversion process under 515 nm excitation,even the energy of which is less than that of the C-exciton.Furthermore,the capacity to efficiently occupy band-edge A-exciton states leads to longer lifetimes for both the C-excitons and the A-excitons under conditions of near-resonant excitation,accompanied by an augmented rate of radiative recombination.This study provides a paradigm for optimizing the performance of 2D TMDs-based devices by offering valuable insights into their exciton dynamics.展开更多
Directly correlating the morphology and composition of interfacial water is vital not only for studying water icing under critical conditions but also for understanding the role of protein–water interac-tions in bio-...Directly correlating the morphology and composition of interfacial water is vital not only for studying water icing under critical conditions but also for understanding the role of protein–water interac-tions in bio-relevant systems.In this study,we present a model system to study two-dimensional(2D)water layers under ambient conditions by using self-assembled monolayers(SAMs)supporting the physisorp-tion of the Cytochrome C(Cyt C)protein layer.We observed that the 2D island-like water layers were uniformly distributed on the SAMs as characterized by atomic force microscopy,and their composition was confirmed by nano-atomic force microscopy-infrared spectroscopy and Raman spectroscopy.In addition,these 2D flakes could grow under high-humidity conditions or melt upon the introduction of a heat source.The formation of these flakes is attributed to the activation energy for water desorption from the Cyt C being nearly twofold high than that from the SAMs.Our results provide a new and effective method for further understanding the water–protein interactions.展开更多
Self-assembled monolayers(SAMs),owing to their amphiphilic nature,tend to aggregate,which impedes the formation of a dense and uniform SAM on the substrate.Additionally,the weak adsorption ability of SAMs on the indiu...Self-assembled monolayers(SAMs),owing to their amphiphilic nature,tend to aggregate,which impedes the formation of a dense and uniform SAM on the substrate.Additionally,the weak adsorption ability of SAMs on the indium tin oxide(ITO)surface and the desorption of hydroxyl(OH)from the ITO surface induced by polar solvents can lead to the formation of vacancies.Herein,a dimethylacridine-based SAM is incorporated into the perovskite precursor solution.This SAM can be extruded from the precursor solution and enriched on the bottom surface of the perovskite,filling the vacancies and in situ forming a mixed SAM with MeO-2PACz as a hole-selective layer(HSL).The in situ formed mixed SAM optimizes the energy level alignment between the HSL and the perovskite,facilitating hole extraction and alleviating the residual strain of the perovskite film.Consequently,the perovskite solar cells(PSCs),based on the mixed SAM,achieve a power conversion efficiency(PCE)of 25.69%and exhibit excellent operational stability.When this approach is applied to 1.78 eV bandgap PSC devices,it yields a PCE of 20.08%.This work presents a unique strategy for fabricating both high-quality perovskite films and superior buried interfaces,which is also applicable to wide-bandgap PSCs.展开更多
基金supported by the National Natural Science Foundation of China (Grant No.11574244 for G.Y.G.)the XJTU Research Fund for AI Science (Grant No.2025YXYC011 for G.Y.G.)the Hong Kong Global STEM Professorship Scheme (for X.C.Z.)。
文摘Compared to the well-studied two-dimensional(2D)ferroelectricity,the appearance of 2D antiferroelectricity is much rarer,where local dipoles from the nonequivalent sublattices within 2D monolayers are oppositely oriented.Using NbOCl_(2) monolayer with competing ferroelectric(FE)and antiferroelectric(AFE)phases as a 2D material platform,we demonstrate the emergence of intrinsic antiferroelectricity in NbOCl_(2) monolayer under experimentally accessible shear strain,along with new functionality associated with electric field-induced AFE-to-FE phase transition.Specifically,the complex configuration space accommodating FE and AFE phases,polarization switching kinetics,and finite temperature thermodynamic properties of 2D NbOCl_(2) are all accurately predicted by large-scale molecular dynamics simulations based on deep learning interatomic potential model.Moreover,room temperature stable antiferroelectricity with low polarization switching barrier and one-dimensional collinear polarization arrangement is predicted in shear-deformed NbOCl_(2) monolayer.The transition from AFE to FE phase in 2D NbOCl_(2) can be triggered by a low critical electric field,leading to a double polarization–electric(P–E)loop with small hysteresis.A new type of optoelectronic device composed of AFE-NbOCl_(2) is proposed,enabling electric“writing”and nonlinear optical“reading”logical operation with fast operation speed and low power consumption.
基金supported by the National Key Research and Development Program of China (Grant Nos.2024YFA1409800 for J.Z.and2024YFA1408603 for Q.Z.)the National Natural Science Foundation of China (Grant Nos.12125408,12334004for J.Z.,and 12174363 for Q.Z.)+1 种基金the Innovation Program for Quantum Science and Technology (Grant No.2021ZD0303306 for J.Z.)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB0450101 for J.Z.)。
文摘Electron–hole(e–h)recombination is a fundamental process that governs energy dissipation and device efficiency in semiconductors.In two-dimensional(2D)materials,the formation of tightly bound excitons makes exciton-mediated e–h recombination the dominant decay pathway.In this work,nonradiative e–h recombination within excitons in monolayer MoS2 is investigated using first-principles simulations that combine nonadiabatic molecular dynamics with𝐺𝑊and real-time Bethe–Salpeter equation(BSE)propagation.A two-step process is identified:rapid intervalley redistribution induced by exchange interaction,followed by slower phonon-assisted recombination facilitated by exciton binding.By selectively removing the screened Coulomb and exchange terms from the BSE Hamiltonian,their respective contributions are disentangled—exchange interaction is found to increase the number of accessible recombination pathways,while binding reduces the excitation energy and enhances nonradiative decay.A reduction in recombination lifetime by over an order of magnitude is observed due to the excitonic many-body effects.These findings provide microscopic insights for understanding and tuning exciton lifetimes in 2D transition-metal dichalcogenides.
基金supported by the National Natural Science Foundation of China(Grant Nos.12022508,12074394,and 22125604)Shanghai Supercomputer Center of ChinaShanghai Snowlake Technology Co.Ltd.
文摘The stable nanobubbles adhered to mineral surfaces may facilitate their efficient separation via flotation in the mining industry.However,the state of nanobubbles on mineral solid surfaces is still elusive.In this study,molecular dynamics(MD)simulations are employed to examine mineral-like model surfaces with varying degrees of hydrophobicity,modulated by surface charges,to elucidate the adsorption behavior of nanobubbles at the interface.Our findings not only contribute to the fundamental understanding of nanobubbles but also have potential applications in the mining industry.We observed that as the surface charge increases,the contact angle of the nanobubbles increases accordingly with shape transformation from a pancake-like gas film to a cap-like shape,and ultimately forming a stable nanobubble upon an ordered water monolayer.When the solid–water interactions are weak with a small partial charge,the hydrophobic gas(N_(2))molecules accumulate near the solid surfaces.However,we have found,for the first time,that gas molecules assemble a nanobubble on the water monolayer adjacent to the solid surfaces with large partial charges.Such phenomena are attributed to the formation of a hydrophobic water monolayer with a hydrogen bond network structure near the surface.
基金financial support from the National Natural Science Foundation of China(Grant No.61971201)。
文摘High-resolution transmission electron microscopy(HRTEM)promises rapid atomic-scale dynamic structure imaging.Yet,the precision limitations of aberration parameters and the challenge of eliminating aberrations in Cs-corrected transmission electron microscopy constrain resolution.A machine learning algorithm is developed to determine the aberration parameters with higher precision from small,lattice-periodic crystal images.The proposed algorithm is then validated with simulated HRTEM images of graphene and applied to the experimental images of a molybdenum disulfide(MoS_(2))monolayer with 25 variables(14 aberrations)resolved in wide ranges.Using these measured parameters,the phases of the exit-wave functions are reconstructed for each image in a focal series of MoS_(2)monolayers.The images were acquired due to the unexpected movement of the specimen holder.Four-dimensional data extraction reveals time-varying atomic structures and ripple.In particular,the atomic evolution of the sulfur-vacancy point and line defects,as well as the edge structure near the amorphous,is visualized as the resolution has been improved from about 1.75?to 0.9 A.This method can help salvage important transmission electron microscope images and is beneficial for the images obtained from electron microscopes with average stability.
基金supported by the National Key R&D Program of China(Grant No.2022YFB3505301)the National Key R&D Program of Shanxi Province(Grant No.202302050201014)+1 种基金the National Natural Science Foundation of China(Grant No.12304148)the Natural Science Basic Research Program of Shanxi Province(Grant No.202203021222219)。
文摘Multiferroic tunnel junctions(MFTJs),which combine tunneling magnetoresistance(TMR)and electroresistance(TER)efects,have emerged as key candidates for data storage.Two-dimensional van der Waals(vdW)MFTJs,in particular,are promising spintronic devices for the post-Moore era.However,these vdW MFTJs are typically based on multiferroics composed of ferromagnetic and ferroelectric materials or multilayer magnetic materials with sliding ferroelectricity,which increases device fabrication complexity.In this work,we design a vdW MFTJ using bilayer MoPtGe_(2)S_(6),a material with homologous multiferroicity in each monolayer,combined with symmetric PtTe_(2)electrodes.Using frst-principles calculations based on density functional theory and nonequilibrium Green's functions,we theoretically explore the spin-polarized electronic transport properties of this MFTJ.By controlling the ferroelectric and ferromagnetic polarization directions of bilayer MoPtGe_(2)S_(6),the MFTJ can exhibit six distinct non-volatile resistance states,with maximum TMR(137%)and TER(1943%)ratios.Under biaxial strain,TMR and TER can increase to 265%and 4210%,respectively.The TER ratio also increases to 2186%under a 0.1 V bias voltage.Remarkably,the MFTJ exhibits a pronounced spin-fltering and a signifcant negative diferential resistance efect.These fndings not only highlight the potential of monolayer multiferroic MoPtGe_(2)S_(6)for MFTJs but also ofer valuable theoretical insights for future experimental investigations.
基金supports by the Grant-in-Aid of Scientific Research of Challenging Research(Exploratory)(JP23K17738)to TS from MEXT of Japanthe 41st grant of research from Nippon Sheet Glass Foundation for Materials Science and Engineering to TS.
文摘A redox-active monolayer on an optically transparent electrode constitutes a typical platform for spectroelectrochemical sensing.The necessity for its sophistication arises from the availability of multi-dimensional sensing signals.Simultaneous monitoring of the redox current and color change synchronized with the oxidation state change significantly enhances sen-sitivity and selectivity.This study aimed to elucidate the modification of an indium tin oxide(ITO)electrode with a viologen monolayer with an ordered orientation.Novel methods were developed to immobilize a viologen molecule bearing a car-boxyl group to form assembled monolayers through a condensation reaction using 1-ethyl-3-(3-dimethylaminopropyl)-car-bodiimide with N-hydroxy-succinimide(EDC/NHS).In the two methods of immobilization,one utilizes a two-step process to firstly form an aromatic siloxane base layer and subsequently attach the viologen derivative through an amide linkage by post-amidation.The other employs a direct ester linkage between the hydroxyl groups of the ITO surface and the car-boxyl group of the viologen derivative.The latter method was also applied to immobilize a ferrocenyl group at a very short distance from the ITO surface.Potential-modulated UV-visible transmission absorption spectral measurement techniques with oblique incidence of plane-polarized light were employed to determine the orientation of the longitudinal axis of the reduced form of the viologen.The frequency dependence data of the potential-modulated transmission absorption signals were utilized to analyze the electron transfer kinetics.The performance of the two viologen-modified electrodes was com-pared to that of an ITO modified by post-amidation to the most commonly used base layer prepared with 3-aminopropyl triethoxysilane.
基金supported by the National Natural Science Foundation of China(Grant Nos.12074213,11574108,and 12104253)the National Key R&D Program of China(Grant No.2022YFA1403103)+2 种基金the Major Basic Program of the Natural Science Foundation of Shandong Province(Grant No.ZR2021ZD01)the Natural Science Foundation of Shandong Provincial(Grant No.ZR2023MA082)the Project of Introduction and Cultivation for Young Innovative Talents in Colleges and Universities of Shandong Province。
文摘Ferromagnetic materials play an important role in memory materials,but conventional control methods are often limited by issues such as high power consumption and volatility.Multiferroic heterostructures provide a promising alternative to achieve low power consumption and nonvolatile electric control of magnetic properties.In this paper,a two-dimensional multiferroic van der Waals heterostructure OsCl_(2)/Sc_(2)CO_(2),which is composed of ferromagnetic monolayer OsCl_(2)and ferroelectric monolayer Sc_(2)CO_(2),is studied by first-principles density functional theory.The results show that by reversing the direction of the electric polarization of Sc_(2)CO_(2),OsCl_(2)can be transformed from a semiconductor to a half-metal,demonstrating a nonvolatile electrical manipulation of the heterostructure through ferroelectric polarization.The underlying physical mechanism is explained by band alignments and charge density differences.Furthermore,based on the heterostructure,we construct a multiferroic tunnel junction with a tunnel electroresistance ratio of 3.38×10^(14)%and a tunnel magnetoresistance ratio of 5.04×10^(6)%,allowing control of conduction states via instantaneous electric or magnetic fields.The findings provide a feasible strategy for designing advanced nanodevices based on the giant tunnel electroresistance and tunnel magnetoresistance effects.
文摘The labels of VU1 and VU2 in Fig.1(b)of the paper[Chin.Phys.B 34046801(2025)]were not correctly placed.The correct figure is provided.This modification does not affect the result presented in the paper.
基金supported by the National Nature Science Foundation of China (Nos. 61671362 and 62071366)。
文摘Two dimensional(2D) materials based on boron and carbon have attracted wide attention due to their unique properties. BC compounds have rich active sites and diverse chemical coordination, showing great potential in optoelectronic applications. However, due to the limitation of calculation and experimental conditions, it is still a challenging task to predict new 2D BC monolayer materials. Specifically, we utilized Crystal Diffusion Variational Autoencoder(CDVAE) and pre-trained Materials Graph Neural Network with 3-Body Interactions(M3GNet) model to generate novel and stable BCP materials. Each crystal structure was treated as a high-dimensional vector, where the encoder extracted lattice information and element coordinates, mapping the high-dimensional data into a low-dimensional latent space. The decoder then reconstructed the latent representation back into the original data space. Additionally, our designed attribute predictor network combined the advantages of dilated convolutions and residual connections,effectively increasing the model's receptive field and learning capacity while maintaining relatively low parameter count and computational complexity. By progressively increasing the dilation rate, the model can capture features at different scales. We used the DFT data set of about 1600 BCP monolayer materials to train the diffusion model, and combined with the pre-trained M3GNet model to screen the best candidate structure. Finally, we used DFT calculations to confirm the stability of the candidate structure.The results show that the combination of generative deep learning model and attribute prediction model can help accelerate the discovery and research of new 2D materials, and provide effective methods for exploring the inverse design of new two-dimensional materials.
基金supported by funding from the Energy Materials and Surface Sciences Unit of the Okinawa Institute of Science and Technology Graduate University,the OIST R&D Cluster Research Program,the OIST Proof of Concept(POC)Program,the JSPS KAKENHI Grant Number JP21F21754 and Alexander von Humboldt Foundation。
文摘Self-assembled monolayers(SAMs)are widely used as hole transport materials in inverted perovskite solar cells,offering low parasitic absorption and suitability for semitransparent and tandem solar cells.While SAMs have shown to be promising in small-area devices(≤1 cm^(2)),their application in larger areas has been limited by a lack of knowledge regarding alternative deposition methods beyond the common spin-coating approach.Here,we compare spin-coating and upscalable methods such as thermal evaporation and spray-coating for[2-(9H-carbazol-9-yl)ethyl]phosphonic acid(2PACz),one of the most common carbazole-based SAMs.The impact of these deposition methods on the device performance is investigated,revealing that the spray-coating technique yields higher device performance.Furthermore,our work provides guidelines for the deposition of SAM materials for the fabrication of perovskite solar modules.In addition,we provide an extensive characterization of 2PACz films focusing on thermal evaporation and spray-coating methods,which allow for thicker 2PACz deposition.It is found that the optimal 2PACz deposition conditions corresponding to the highest device performances do not always correlate with the monolayer characteristics.
基金supported by the National Natural Science Foundation of China(62205180)the Natural Science Foundation of Shandong Province(ZR2022QF029)the Taishan Scholar Program of Shandong Province(Young Scientist).
文摘Semiconductor colloidal quantum wells(CQWs)with atomic-precision layer thickness are rapidly gaining attention for next-generation optoelectronic applications due to their tunable optical and electronic properties.In this study,we investigate the dielectric and optical characteristics of CdSe CQWs with monolayer numbers ranging from 2 to 7,synthesized via thermal injection and atomic layer(c-ALD)deposition techniques.Through a combination of spectroscopic ellipsometry(SE)and first-principles calculations,we demonstrate the significant tunability of the bandgap,refractive index,and extinction coefficient,driven by quantum confinement effects.Our results show a decrease in bandgap from 3.1 to 2.0 eV as the layer thickness increases.Furthermore,by employing a detailed analysis of the absorption spectra,accounting for exciton localization and asymmetric broadening,we precisely capture the relationship between monolayer number and exciton binding energy.These findings offer crucial insights for optimizing CdSe CQWs in optoelectronic device design by leveraging their layer-dependent properties.
基金supported by the National Key R&D Program of China(Grant No.2021YFB3501503)the National Natural Science Foundation of China(Grant Nos.52271016 and 52188101)the Foundation of Liaoning Province(Grant No.XLYC2203080)。
文摘The dual quantum spin Hall insulator(QSHI)is a newly discovered topological state in the two-dimensional(2D)material TaIrTe_(4),which exhibits both a traditional Z_(2)band gap at the charge neutrality point and a Van Hove singularity(VHS)that induces a correlated Z_(2)band gap with weak doping.Inspired by the recent progress in theoretical understanding and experimental measurements,a promising dual QSHI is predicted in the counterpart material of the NbIrTe_(4)monolayer by first-principles calculations.In addition to the well-known band inversion at the charge neutrality point,two new band inversions are found after a charge density wave(CDW)phase transition when the chemical potential is near the VHS:one direct and one indirect Z_(2)band gap.The VHSinduced non-trivial band gap is approximately 10 meV,significantly larger than that of TaIrTe_(4).Furthermore,as the newly generated band gap is mainly dominated by the 4d orbitals of Nb,the electronic correlation effects should be stronger for NbIrTe_(4)than for TaIrTe_(4).Therefore,the dual QSHI state in the NbIrTe_(4)monolayer is expected to provide a strong platform for investigating the interplay between topologies and correlation effects.
基金supported by the National Key Research and Development Program of China(Grant No.2023YFA1610000)the National Natural Science Foundation of China(Grant Nos.12304036 and 12304265)+1 种基金the Basic and Applied Basic Research Foundation of Guangdong Province,China(Grant No.2023A1515010071)the Fundamental Research Funds for the Central Universities to Sun Yat-sen University(Grant No.23xkjc016).
文摘Monolayer CrI_(3),crystalizing in the P31m space group,is a prototypical two-dimensional(2D)material for observing intrinsic ferromagnetic order.However,its relatively low Curie temperature(T_(C))of 45 K severely limits its practical applications,highlighting the need to explore novel metastable polymorphs with enhanced magnetic properties.In this study,we employ a global crystal structure search technique combined with first-principles calculations to systematically investigate new monolayer CrI_(3)phases.Our structural predictions identify two novel polymorphs with Cm and P2/m space groups,both of which are dynamically stable and exhibit significantly higher T_(C)values of 145 K and 81 K,respectively.Electronic property calculations show that the Cm phase is a half-metal,while the P2/m phase is semiconducting with a bandgap of 0.14 eV.Monte Carlo simulations attribute these enhanced T_(C)values to a notable increase in exchange interactions.These findings expand the known phase space of CrI_(3)and provide a promising pathway for designing hightemperature 2D ferromagnets for next-generation spintronic applications.
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%).
基金supported by the National Natural Science Foundation of China(22305119,12204234)the Natural Science Foundation of Jiangsu Province(BK20220878)+3 种基金the Fundamental Research Funds for the Central Universities(NS2023059)the China Postdoctoral Science Foundation(2022TQ0157,2023M741695)the Liaoning University Talent Introduction Research Startup Project(d295000048)the Center for Microscopy and Analysis of Nanjing University of Aeronautics and Astronautics for characterization support。
文摘The optimization of hole transport layer(HTL)is crucial for achieving high efficiency and stability in inverted perovskite solar cells(PSCs)due to its role in facilitating hole transport and passivating the perovskite bottom interface.While self-assembled monolayers(SAMs)are commonly used for this purpose,the inherent limitations of a single SAM,such as fixed energy levels and rigid structure,restrict their adaptability for different perovskite components and further efficiency enhancement.Here,we demonstrate a stepwise deposition method for SAM-based HTLs to address this issue.We regulated the energy level gradient by depositing two SAMs with distinct energy levels,while the interactions between the phosphate groups in the SAMs and perovskite effectively reduce defect density at the bottom interface of the perovskite film.The as-fabricated PSCs achieved enhanced efficiency and stability with PCEs of 25.7% and 24.0% for rigid and flexible PSCs,respectively;these devices maintain 90% of their initial PCE after 500 h of maximum power point tracking,and retain 98% of their initial PCE after 4,000 bending cycles,representing one of the most stable flexible PSCs reported to date.
基金supported by the National Natural Science Foundation of China(Nos.22175060 and 22376062)JSPS Grant-in-Aid for Scientific Research(Nos.JP21H05235,JP22H05478 and JP22F22358)+1 种基金China Postdoctoral Science Foundation(No.2022M722867)the Key Research Project of Higher Education Institutions in Henan Province(No.23A530001).
文摘Exploring earth-abundant,highly active bifunctional electrocatalysts for efficient hydrogen and oxygen evolution is crucial for water splitting.However,due to their distinct free energies and conducting behaviors(electron/hole),balancing the catalytic efficiency between hydrogen and oxygen evolution remains challenging for achieving bifunctional electrocatalysts.Here,we report a locally-doped MoS_(2)monolayer with an in-plane heterostructure acting as a bifunctional electrocatalyst and apply it to the overall water splitting.In this heterostructure,the core region contains Mo/S vacancies,while the ring region was doped by Fe atoms(in two substitution configurations:1FeMo and 3FeMo-VS clusters)with a p-type conductive characteristic.Our micro-cell measurements,combined with density functional theory(DFT)calculations,reveal that the vacancies-rich core region presents remarkable hydrogen evolution reaction(HER)activity while the Fe-doped ring gives an excellent oxygen evolution reaction(OER)activity,thus forming an in-plane bifunctional electrocatalyst.Finally,as a proof-of-concept for overall water splitting,we constructed a full-cell configuration based on a locally-doped MoS_(2)monolayer,which achieved a cell voltage of 1.87 V at 10 mA·cm^(-2),demonstrating outstanding performance in strong acid electrolytes.Our work provides insight into the hetero-integration of bifunctional electrocatalysts at the atomic level,paving the way for designing transition metal dichalcogenide catalysts with activity-manipulated regions capable of multiple reactions.
基金supported by the Natural Science Foundation of China(22425903,U24A20568,61705102,62288102,22409091,22409090 and 62205142)the National Key R&D Program of China(2023YFB4204500)the Jiangsu Provincial Departments of Science and Technology(BE2022023,BK20220010,BZ2023060,BK20240561,and BK20240562)。
文摘Inverted p-i-n perovskite solar cells(PSCs)based on self-assembled monolayers(SAMs)as hole-selective layers(HSLs)have produced potential record efficiencies of more than 26%by tuning work function,dipole,and passivation defects.However,the stability of the SAM molecules,the stability of the molecular anchoring conformation,and the impact on the stability of subsequent PSCs have not been clearly elucidated.In this review,we systematically discussed the intrinsic connection between the molecular conformation(including anchoring groups,spacer groups,and terminal groups)and the stability of SAMs.Sequentially,the research progress of SAMs as HSLs in improving the stability of PSCs is summarized,including photostability,thermal stability,ion migration,and residual stress.Finally,we look forward to the shortcomings and possible challenges of using SAMs as HSLs for inverted PSCs.
基金supported by the National Natural Science Foundation of China(Grant Nos.12474421 and 12104066)the Fund from Education Department of Jilin Province(Grant Nos.JJKH20250473KJ and JJKH20241413KJ)the Fund from Department of Science and Technology of Jilin Province(Grant No.YDZJ202101ZYTS041)。
文摘Insight into exciton dynamics of two-dimensional(2D)transition metal dichalcogenides(TMDs)is critical for the optimization of their performance in photonic and optoelectronic devices.Although current researches have primarily concentrated on the near-resonant excitation scenario in 2D TMDs,the case of excitation energies resonating with highenergy excitons or higher energies has yet to be fully elucidated.Here,a comparative analysis is conducted between highenergy excitation(360 nm)and near-resonant excitation(515 nm)utilizing transient absorption spectroscopy to achieve a comprehensive understanding of the exciton dynamics within monolayer WS_(2).It is observed that the high-energy C-exciton can be generated via an up-conversion process under 515 nm excitation,even the energy of which is less than that of the C-exciton.Furthermore,the capacity to efficiently occupy band-edge A-exciton states leads to longer lifetimes for both the C-excitons and the A-excitons under conditions of near-resonant excitation,accompanied by an augmented rate of radiative recombination.This study provides a paradigm for optimizing the performance of 2D TMDs-based devices by offering valuable insights into their exciton dynamics.
基金supported by the National Natural Science Foundation of China(22273045,52488101 and 22472043)Ningbo Youth Science and Technology Innovation Leading Talent(2023QL041)Tsinghua University Independent Scientific Research Plan for Young Investigator,Tsinghua University Dushi Program,and Initiative Scientific Research Program。
文摘Directly correlating the morphology and composition of interfacial water is vital not only for studying water icing under critical conditions but also for understanding the role of protein–water interac-tions in bio-relevant systems.In this study,we present a model system to study two-dimensional(2D)water layers under ambient conditions by using self-assembled monolayers(SAMs)supporting the physisorp-tion of the Cytochrome C(Cyt C)protein layer.We observed that the 2D island-like water layers were uniformly distributed on the SAMs as characterized by atomic force microscopy,and their composition was confirmed by nano-atomic force microscopy-infrared spectroscopy and Raman spectroscopy.In addition,these 2D flakes could grow under high-humidity conditions or melt upon the introduction of a heat source.The formation of these flakes is attributed to the activation energy for water desorption from the Cyt C being nearly twofold high than that from the SAMs.Our results provide a new and effective method for further understanding the water–protein interactions.
基金supported by the Young Cross Team Project of CAS(No.JCTD-2021-14)the National Natural Science Foundation of China(51925206)Gusu Innovation and Entrepreneur Leading Talents(ZXL2022466)。
文摘Self-assembled monolayers(SAMs),owing to their amphiphilic nature,tend to aggregate,which impedes the formation of a dense and uniform SAM on the substrate.Additionally,the weak adsorption ability of SAMs on the indium tin oxide(ITO)surface and the desorption of hydroxyl(OH)from the ITO surface induced by polar solvents can lead to the formation of vacancies.Herein,a dimethylacridine-based SAM is incorporated into the perovskite precursor solution.This SAM can be extruded from the precursor solution and enriched on the bottom surface of the perovskite,filling the vacancies and in situ forming a mixed SAM with MeO-2PACz as a hole-selective layer(HSL).The in situ formed mixed SAM optimizes the energy level alignment between the HSL and the perovskite,facilitating hole extraction and alleviating the residual strain of the perovskite film.Consequently,the perovskite solar cells(PSCs),based on the mixed SAM,achieve a power conversion efficiency(PCE)of 25.69%and exhibit excellent operational stability.When this approach is applied to 1.78 eV bandgap PSC devices,it yields a PCE of 20.08%.This work presents a unique strategy for fabricating both high-quality perovskite films and superior buried interfaces,which is also applicable to wide-bandgap PSCs.
