Aqueous electrochromic battery(ECB)has shown intense potential for achieving energy storage and saving simultaneously.While tungsten oxide(WO_(3))is the most promising EC material for commercialization,the cycling sta...Aqueous electrochromic battery(ECB)has shown intense potential for achieving energy storage and saving simultaneously.While tungsten oxide(WO_(3))is the most promising EC material for commercialization,the cycling stability of WO_(3)-based aqueous ECBs is currently unsatisfactory due to the repeated phase transition during the redox process and the corrosion by acidic electrolytes.Herein,we present a titanium-tungsten oxide alloy(Ti-WO_(3))with controllable morphology and crystal phase synthesized by a facile hot injection method to overcome the challenges.In contrast to conventional monoclinic WO_(3),the Ti-WO_(3)nanorods can stably maintain their cubic crystal phase during the redox reaction in an acidic electrolyte,thus leading to dramatically enhanced response speed and cycling stability,Specifically,when working in a well-matched hybrid Al^(3+)/Zn^(2+)aqueous electrolyte,our phasetransition-free cubic Ti-WO_(3)exhibits an ultra-high cycling stability(>20000 cycles),fast response speed(3,95 s/4,65 s for bleaching/coloring),as well as excellent discharge areal capacity of 214.5 mA h m^(-2),We further fabricate a fully complementa ry aqueous electrochromic device,for the first time,using a Ti-WO_(3)/Prussian blue device architecture.Remarkably,the complementary ECB shows>10000 stable operation cycles,attesting to the feasibility of our Ti-WO_(3)for practical applications.Our work validates the significance of inhibiting the phase transitions of WO_(3)during the electrochromic process for realizing highly cyclable aqueous ECB,which can possibly provide a generalized design guidance for other high-quality metallic oxides for electrochemical applications.展开更多
We have grown a YCrO_(3)single crystal by the floating-zone method and studied its temperature-dependent crystalline structure and magnetization by x-ray powder diffraction and PPMS DynaCool measurements.All diffracti...We have grown a YCrO_(3)single crystal by the floating-zone method and studied its temperature-dependent crystalline structure and magnetization by x-ray powder diffraction and PPMS DynaCool measurements.All diffraction patterns were well indexed by an orthorhombic structure with space group of Pbnm(No.62).From 36 K to 300 K,no structural phase transition occurs in the pulverized YCrO_(3)single crystal.The antiferromagnetic phase transition temperature was determined as T_(N)=141.58(5)K by the magnetization versus temperature measurements.We found weak ferromagnetic behavior in the magnetic hysteresis loops below TN.Especially,we demonstrated that the antiferromagnetism and weak ferromagnetism appear simultaneously upon cooling.The lattice parameters(a,b,c,and V)deviate downward from the Grüneisen law,displaying an anisotropic magnetostriction effect.We extracted temperature variation of the local distortion parameterΔ.Compared to theΔvalue of Cr ions,Y,O1,and O2 ions show one order of magnitude largerΔvalues indicative of much stronger local lattice distortions.Moreover,the calculated bond valence states of Y and O2 ions have obvious subduction charges.展开更多
Layered magnetic materials,such as MnBi_(2)Te_(4),have drawn much attention owing to their potential for realizing twodimensional(2D)magnetism and possible topological states.Recently,FeBi_(2)Te_(4),which is isostruct...Layered magnetic materials,such as MnBi_(2)Te_(4),have drawn much attention owing to their potential for realizing twodimensional(2D)magnetism and possible topological states.Recently,FeBi_(2)Te_(4),which is isostructural to MnBi_(2)Te_(4),has been synthesized in experiments,but its detailed magnetic ordering and band topology have not been clearly understood yet.Here,based on first-principles calculations,we investigate the magnetic and electronic properties of FeBi_(2)Te_(4)in bulk and 2D forms.We show that different from MnBi_(2)Te_(4),the magnetic ground states of bulk,single-layer,and bilayer FeBi_(2)Te_(4)all favor a 120°noncollinear antiferromagnetic ordering,and they are topologically trivial narrow-gap semiconductors.For the bilayer case,we find that a quantum anomalous Hall effect with a unit Chern number is realized in the ferromagnetic state,which may be achieved in experiment by an external magnetic field or by magnetic proximity coupling.Our work clarifies the physical properties of the new material system of FeBi_(2)Te_(4)and reveals it as a potential platform for studying magnetic frustration down to 2D limit as well as quantum anomalous Hall effect.展开更多
The thermoelectric(TE)materials and corresponding TE devices can achieve direct heat-to-electricity conversion,thus have wide applications in heat energy harvesting(power generator),wearable electronics and local cool...The thermoelectric(TE)materials and corresponding TE devices can achieve direct heat-to-electricity conversion,thus have wide applications in heat energy harvesting(power generator),wearable electronics and local cooling.In recent years,aerogel-based TE materials have received considerable attention and have made remarkable progress because of their unique structural,electrical and thermal properties.In this review,the recent progress in both organic,inorganic,and composite/hybrid TE aerogels is systematically summarized,including the main constituents,preparation method,TE performance,as well as factors affecting the TE performance and the corresponding mechanism.Moreover,two typical aerogel-based TE devices/generators are compared and analyzed in terms of assembly modes and output performance.Finally,the present challenges and some tentative suggestions for future research prospects are provided in conclusion.展开更多
The poor cycling stability of graphite in traditional ester electrolyte limits its applications as anodes for potassium ion batteries(KIBs).Herein,we demonstrate that the introduction of cyclic ether co-solvents into ...The poor cycling stability of graphite in traditional ester electrolyte limits its applications as anodes for potassium ion batteries(KIBs).Herein,we demonstrate that the introduction of cyclic ether co-solvents into ester electrolytes can remarkably enhance the cycling stability of graphite anodes.The graphite anode in ester electrolyte with cyclic ether could achieve a reversible capacity of 196.1 m Ah g^(-1) after 100 cycles at 0.3 C(1 C=280 m A g^(-1)),about three times higher than those in ester electrolytes with or without linear ether.Compared with the SEI formed in ester electrolytes,the addition of tetrahydrofuran promotes the generation of K_(2)CO_(3) and ethylene oxide oligomers(PEO),of which the K_(2)CO_(3) is expected to be more conductive and PEO is mechanically robust.The more uniform,conductive and stable solid electrolyte interphases(SEIs)on graphite in electrolytes with cyclic ethers contribute to the enhancement of the electrochemical performances of graphite.This work provides a novel design of commercialized electrolytes to achieve high-performance anodes for KIBs,which potentially accelerates the development of KIBs.展开更多
Manganese cobaltite(MnCo_(2)_(4))is a promising electrode material because of its attractive redox chemistry and excellent charge storage capability.Our previous work demonstrated that the octahedrally-coordinated Mn ...Manganese cobaltite(MnCo_(2)_(4))is a promising electrode material because of its attractive redox chemistry and excellent charge storage capability.Our previous work demonstrated that the octahedrally-coordinated Mn are prone to react with the hydroxyl ions in alkaline electrolyte upon electrochemical cycling and separates on the surface of spinel to reconstruct into d-MnO_(2) nanosheets irreversibly,thus results in a change of the reaction mechanism with Kþion intercalation.However,the low capacity has greatly limited its practical application.Herein,we found that the tetrahedrally-coordinated Co_(2) þions were leached when MnCo_(2)_(4) was equilibrated in 1 mol L^(-1) HCl solution,leading to the formation of layered CoOOH on MnCo_(2)_(4) surface which is originated from the covalency competition induced selective breakage of the CoT–O bond in CoT–O–CoO and subsequent rearrangement of free Co_(6) octahedra.The as-formed CoOOH is stable upon cycling in alkaline electrolyte,exhibits conversion reaction mechanism with facile proton diffusion and is free of massive structural evolution,thus enables utilization of the bulk electrode material and realizes enhanced specific capacity as well as facilitated charge transfer and ion diffusion.In general,our work not only offers a feasible approach to deliberate modification of MnCo_(2)_(4)'s surface structure,but also provides an in-depth understanding of its charge storage mechanism,which enables rational design of the spinel oxides with promising charge storage properties.展开更多
Metal halide perovskite nanostructures have emerged as low-dimensional semiconductors of great significance in many fields such as photovoltaics,photonics,and optoelectronics.Extensive efforts on the controlled synthe...Metal halide perovskite nanostructures have emerged as low-dimensional semiconductors of great significance in many fields such as photovoltaics,photonics,and optoelectronics.Extensive efforts on the controlled synthesis of perovskite nanostructures have been made towards potential device applications.The engineering of their band structures holds great promise in the rational tuning of the electronic and optical properties of perovskite nanostructures,which is one of the keys to achieving efficient and multifunctional optoelectronic devices.In this article,we summarize recent advances in band structure engineering of perovskite nanostructures.A survey of bandgap engineering of nanostructured perovskites is firstly presented from the aspects of dimensionality tailoring,compositional substitution,phase segregation and transition,as well as strain and pressure stimuli.The strategies of electronic doping are then reviewed,including defect-induced self-doping,inorganic or organic molecules-based chemical doping,and modification by metal ions or nanostructures.Based on the bandgap engineering and electronic doping,discussions on engineering energy band alignments in perovskite nanostructures are provided for building high-performance perovskite p-n junctions and heterostructures.At last,we provide our perspectives in engineering band structures of perovskite nanostructures towards future low-energy optoelectronics technologies.展开更多
Quasi-2D perovskites have attracted tremendous interest for application as lightemission layers in light-emitting diodes(LEDs).However,the heterogeneous n phase and non-uniform distribution still severely limit the fu...Quasi-2D perovskites have attracted tremendous interest for application as lightemission layers in light-emitting diodes(LEDs).However,the heterogeneous n phase and non-uniform distribution still severely limit the further development of quasi-2D perovskite LEDs(Pero-LEDs).Meanwhile,the increased defect density caused by the reduced dimension and grain size induces non-radiative recombination and further deteriorates the device performance.Here,we found that a series of molecules containing phosphoryl chloride functional groups have noticeable enhancement effects on the device performance of quasi-2D Pero-LEDs.Then,we studied the modification mechanism by focusing on the bis(2-oxo-3-oxazolidinyl)phosphinic chloride(BOPCl).It is concluded that the BOPCl can not only regulate the phase distribution by decreasing the crystallization rate but also remain in the grain boundaries and passivate the defects.As a result,the corresponding quasi-2D Pero-LEDs obtained a maximum external quantum efficiency(EQE_(max))of 20.82%and an average EQE(EQE_(ave))of around 20%on the optimal 50 devices,proving excellent reproducibility.Our work provides a new selection of molecular types for regulating the crystallization and passivating the defects of quasi-2D perovskite films.展开更多
The wearable sensors have recently attracted considerable attentions as communication interfaces through the information perception,decoding,and conveying process.However,it is still challenging to obtain a sensor tha...The wearable sensors have recently attracted considerable attentions as communication interfaces through the information perception,decoding,and conveying process.However,it is still challenging to obtain a sensor that can convert detectable signals into multiple outputs for convenient,e cient,cryptic,and high-capacity information transmission.Herein,we present a capacitive sensor of magnetic field based on a tilted flexible micromagnet array(t-FMA)as the proposed interaction interface.With the bidirectional bending capability of t-FMA actuated by magnetic torque,the sensor can recognize both the magnitude and orientation of magnetic field in real time with non-overlapping capacitance signals.The optimized sensor exhibits the high sensitivity of over 1.3 T-1 and detection limit down to 1 mT with excellent durability.As a proof of concept,the sensor has been successfully demonstrated for convenient,e cient,and programmable interaction systems,e.g.,touchless Morse code and Braille communication.The distinguishable recognition of the magnetic field orientation and magnitude further enables the sensor unit as a high-capacity transmitter for cryptic information interaction(e.g.,encoded ID recognition)and multi-control instruction outputting.We believe that the proposed magnetic field sensor can open up a potential avenue for future applications including information communication,virtual reality device,and interactive robotics.展开更多
Pb-free Sn-based perovskite solar cells(PSCs) have recently made inspiring progress, and power conversion efficiency(PCE) of 14.8% has been achieved. However, due to the energy-level mismatch and poor interfacial cont...Pb-free Sn-based perovskite solar cells(PSCs) have recently made inspiring progress, and power conversion efficiency(PCE) of 14.8% has been achieved. However, due to the energy-level mismatch and poor interfacial contact between commonly used hole transport layer(i.e., poly(3,4-ethylenedioxythio phene):poly(styrene sulfonate), PEDOT:PSS) and FASnI_(3) film, it is still challenging to effectively extract holes at the interface. Owing to the p-type nature of Sn-based perovskites, the efficient hole extraction is of particular significance to improve the PCE of their solar cells. In this work, for the first time, the role of chiral cations, a-methylbenzylamine(S-/R-/rac-MBA), in promoting hole transportation of FASnI_(3)-based PSCs is demonstrated. The introduction of MBAs is found to form 2D/3D film with lowdimensional structures locating at PEDOT:PSS/FASnI_(3) interface, which facilitates the energy level alignment and efficient charge transfer at the interface. Importantly, chiral-induced spin selectivity(CISS)effect of R-MBA_(2)SnI_(4)induced by chiral R-MBA cation is found to further assist the specific interfacial transport of accumulated holes. As a result, R-MBA-based PSCs achieve decent PCE of 10.73% with much suppressed hysteresis and enhanced device stability. This work opens up a new strategy to efficiently promote the interfacial extraction of accumulated charges in working PSCs.展开更多
The spin-1/2 kagome antiferromagnets are key prototype materials for studying frustrated magnetism.Three isostructural kagome antiferromagnets LnCu_(3)(OH)_(6)Cl_(3)(Ln=Gd,Tb,Dy)have been successfully synthesized by t...The spin-1/2 kagome antiferromagnets are key prototype materials for studying frustrated magnetism.Three isostructural kagome antiferromagnets LnCu_(3)(OH)_(6)Cl_(3)(Ln=Gd,Tb,Dy)have been successfully synthesized by the hydrothermal method.LnCu_(3)(OH)_(6)Cl_(3) adopts space group P3m1 and features the layered Cu-kagome lattice with lanthanide Ln3+cations sitting at the center of the hexagons.Although heavy lanthanides(Ln=Gd,Tb,Dy)in LnCu_(3)(OH)_(6)Cl_(3) provide a large effective magnetic moment and ferromagnetic-like spin correlations compared to light-lanthanides(Nd,Sm,Eu)analogues,Cu-kagome holds an antiferromagnetically ordered state at around 17 K like YCu_(3)(OH)_(6)Cl_(3).展开更多
In the realm of virtual reality(VR),haptic feedback is integral to enhance the immersive experience;yet,existing wearable devices predominantly rely on skin contact feedback,lacking options for compact and non-contact...In the realm of virtual reality(VR),haptic feedback is integral to enhance the immersive experience;yet,existing wearable devices predominantly rely on skin contact feedback,lacking options for compact and non-contact breeze-sense feedback.Herein,we propose a compact and non-contact working model piezoelectret actuator for providing a gentle and safe breeze sensation.This easy-fabricated and flexible breeze-sense generator with thickness around 1 mm generates air flow pressure up to~163 Pa,which is significantly sensed by human skin.In a typical demonstration,the breeze-sense generators array showcases its versatility by employing multiple coded modes for non-contact information transmitting.The thin thinness and good flexibility facilitate seamless integration with wearable VR setups,and the wearable arrays empower volunteers to precisely perceive the continuous and sudden breeze senses in the virtual environments.This work is expected to inspire developing new haptic feedback devices that play pivotal roles in human-machine interfaces for VR applications.展开更多
基金funded by the Science and Technology Development Fund,Macao SAR(File no.0052/2021/AGJ,0027/2023/AMJ,0083/2023/ITP2 and 0107/2023/AFJ)the Multi-Year Research Grants(MYRG2022-00063-IAPME,MYRG-GRG2023-00230-IAPME-UMDF)from the University of Macao+1 种基金the Guangdong Science and Technology Plan(2022A0505020022)the Major Science and Technology Research and Development Project of Jiangxi Province(20223AAE01003)。
文摘Aqueous electrochromic battery(ECB)has shown intense potential for achieving energy storage and saving simultaneously.While tungsten oxide(WO_(3))is the most promising EC material for commercialization,the cycling stability of WO_(3)-based aqueous ECBs is currently unsatisfactory due to the repeated phase transition during the redox process and the corrosion by acidic electrolytes.Herein,we present a titanium-tungsten oxide alloy(Ti-WO_(3))with controllable morphology and crystal phase synthesized by a facile hot injection method to overcome the challenges.In contrast to conventional monoclinic WO_(3),the Ti-WO_(3)nanorods can stably maintain their cubic crystal phase during the redox reaction in an acidic electrolyte,thus leading to dramatically enhanced response speed and cycling stability,Specifically,when working in a well-matched hybrid Al^(3+)/Zn^(2+)aqueous electrolyte,our phasetransition-free cubic Ti-WO_(3)exhibits an ultra-high cycling stability(>20000 cycles),fast response speed(3,95 s/4,65 s for bleaching/coloring),as well as excellent discharge areal capacity of 214.5 mA h m^(-2),We further fabricate a fully complementa ry aqueous electrochromic device,for the first time,using a Ti-WO_(3)/Prussian blue device architecture.Remarkably,the complementary ECB shows>10000 stable operation cycles,attesting to the feasibility of our Ti-WO_(3)for practical applications.Our work validates the significance of inhibiting the phase transitions of WO_(3)during the electrochromic process for realizing highly cyclable aqueous ECB,which can possibly provide a generalized design guidance for other high-quality metallic oxides for electrochemical applications.
基金the opening project of State Key Laboratory of High Performance Ceramics and Superfine Microstructure(Grant No.SKL201907SIC)Science and Technology Development Fund,Macao SAR,China(File Nos.0090/2021/A2 and 0051/2019/AFJ)+2 种基金Guangdong Basic and Applied Basic Research Foundation,China(GuangdongDongguan Joint Fund No.2020B1515120025)University of Macao(MYRG2020-00278-IAPME and EF030/IAPMELHF/2021/GDSTIC)Guangdong-Hong Kong-Macao Joint Laboratory for Neutron Scattering Science and Technology(Grant No.2019B121205003)。
文摘We have grown a YCrO_(3)single crystal by the floating-zone method and studied its temperature-dependent crystalline structure and magnetization by x-ray powder diffraction and PPMS DynaCool measurements.All diffraction patterns were well indexed by an orthorhombic structure with space group of Pbnm(No.62).From 36 K to 300 K,no structural phase transition occurs in the pulverized YCrO_(3)single crystal.The antiferromagnetic phase transition temperature was determined as T_(N)=141.58(5)K by the magnetization versus temperature measurements.We found weak ferromagnetic behavior in the magnetic hysteresis loops below TN.Especially,we demonstrated that the antiferromagnetism and weak ferromagnetism appear simultaneously upon cooling.The lattice parameters(a,b,c,and V)deviate downward from the Grüneisen law,displaying an anisotropic magnetostriction effect.We extracted temperature variation of the local distortion parameterΔ.Compared to theΔvalue of Cr ions,Y,O1,and O2 ions show one order of magnitude largerΔvalues indicative of much stronger local lattice distortions.Moreover,the calculated bond valence states of Y and O2 ions have obvious subduction charges.
基金funding support from the Singapore MOE Ac RF 308 Tier 2(Grant No.T2EP50220-0026)funding support from Shandong Provincial Natural Science Foundation(Grant No.ZR2023QA012)+3 种基金the Special Fund-ing in the Project of Qilu Young Scholar Program of Shandong Universityfunding support from Australian Research Council Future Fellowship(Grant No.FT220100290)funding support from the AINSE postgraduate awardfunding support from the Research and Development Administration Office at the University of Macao(Grants Nos.MYRG2022-00088-IAPME and SRG2021-00003-IAPME)。
文摘Layered magnetic materials,such as MnBi_(2)Te_(4),have drawn much attention owing to their potential for realizing twodimensional(2D)magnetism and possible topological states.Recently,FeBi_(2)Te_(4),which is isostructural to MnBi_(2)Te_(4),has been synthesized in experiments,but its detailed magnetic ordering and band topology have not been clearly understood yet.Here,based on first-principles calculations,we investigate the magnetic and electronic properties of FeBi_(2)Te_(4)in bulk and 2D forms.We show that different from MnBi_(2)Te_(4),the magnetic ground states of bulk,single-layer,and bilayer FeBi_(2)Te_(4)all favor a 120°noncollinear antiferromagnetic ordering,and they are topologically trivial narrow-gap semiconductors.For the bilayer case,we find that a quantum anomalous Hall effect with a unit Chern number is realized in the ferromagnetic state,which may be achieved in experiment by an external magnetic field or by magnetic proximity coupling.Our work clarifies the physical properties of the new material system of FeBi_(2)Te_(4)and reveals it as a potential platform for studying magnetic frustration down to 2D limit as well as quantum anomalous Hall effect.
基金supported by Shenzhen Fundamental Research Program(Grant No.JCYJ20200109105604088)Distinguished Young Talents in Higher Education of Guangdong,China(Project No.2020KQNCX061)。
文摘The thermoelectric(TE)materials and corresponding TE devices can achieve direct heat-to-electricity conversion,thus have wide applications in heat energy harvesting(power generator),wearable electronics and local cooling.In recent years,aerogel-based TE materials have received considerable attention and have made remarkable progress because of their unique structural,electrical and thermal properties.In this review,the recent progress in both organic,inorganic,and composite/hybrid TE aerogels is systematically summarized,including the main constituents,preparation method,TE performance,as well as factors affecting the TE performance and the corresponding mechanism.Moreover,two typical aerogel-based TE devices/generators are compared and analyzed in terms of assembly modes and output performance.Finally,the present challenges and some tentative suggestions for future research prospects are provided in conclusion.
基金financially supported by the National Natural Science Foundation of China(U21A2081,22075074,22179014)the Outstanding Young Scientists Research Funds from Hunan Province(2020JJ2004)+2 种基金the Major Science and Technology Program of Hunan Province(2020WK2013)the Natural Science Foundation of Hunan Province(2021JJ40047)the State Key Laboratory of Materials Processing and Die&Mould Technology,Huazhong University of Science and Technology(P2022-020)。
文摘The poor cycling stability of graphite in traditional ester electrolyte limits its applications as anodes for potassium ion batteries(KIBs).Herein,we demonstrate that the introduction of cyclic ether co-solvents into ester electrolytes can remarkably enhance the cycling stability of graphite anodes.The graphite anode in ester electrolyte with cyclic ether could achieve a reversible capacity of 196.1 m Ah g^(-1) after 100 cycles at 0.3 C(1 C=280 m A g^(-1)),about three times higher than those in ester electrolytes with or without linear ether.Compared with the SEI formed in ester electrolytes,the addition of tetrahydrofuran promotes the generation of K_(2)CO_(3) and ethylene oxide oligomers(PEO),of which the K_(2)CO_(3) is expected to be more conductive and PEO is mechanically robust.The more uniform,conductive and stable solid electrolyte interphases(SEIs)on graphite in electrolytes with cyclic ethers contribute to the enhancement of the electrochemical performances of graphite.This work provides a novel design of commercialized electrolytes to achieve high-performance anodes for KIBs,which potentially accelerates the development of KIBs.
基金supported by the National Key Research and Development Program of China(2022YFE0206300)the National Natural Science Foundation of China(22209047,U21A2081,22075074)+2 种基金Natural Science Foundation of Hunan Province(2020JJ5035)Hunan Provincial Department of Education Outstanding Youth Project(23B0037)Macao Science and Technology Development Fund(Macao SAR,FDCT-0096/2020/A2).
文摘Manganese cobaltite(MnCo_(2)_(4))is a promising electrode material because of its attractive redox chemistry and excellent charge storage capability.Our previous work demonstrated that the octahedrally-coordinated Mn are prone to react with the hydroxyl ions in alkaline electrolyte upon electrochemical cycling and separates on the surface of spinel to reconstruct into d-MnO_(2) nanosheets irreversibly,thus results in a change of the reaction mechanism with Kþion intercalation.However,the low capacity has greatly limited its practical application.Herein,we found that the tetrahedrally-coordinated Co_(2) þions were leached when MnCo_(2)_(4) was equilibrated in 1 mol L^(-1) HCl solution,leading to the formation of layered CoOOH on MnCo_(2)_(4) surface which is originated from the covalency competition induced selective breakage of the CoT–O bond in CoT–O–CoO and subsequent rearrangement of free Co_(6) octahedra.The as-formed CoOOH is stable upon cycling in alkaline electrolyte,exhibits conversion reaction mechanism with facile proton diffusion and is free of massive structural evolution,thus enables utilization of the bulk electrode material and realizes enhanced specific capacity as well as facilitated charge transfer and ion diffusion.In general,our work not only offers a feasible approach to deliberate modification of MnCo_(2)_(4)'s surface structure,but also provides an in-depth understanding of its charge storage mechanism,which enables rational design of the spinel oxides with promising charge storage properties.
基金support from Australian Research Council (ARC, FT150100450, IH150100006 and CE170100039)support from the MCATM and the FLEET+1 种基金the support from Shenzhen Nanshan District Pilotage Team Program (LHTD20170006)support from Guangzhou Science and Technology Program (Grant No. 201804010322)
文摘Metal halide perovskite nanostructures have emerged as low-dimensional semiconductors of great significance in many fields such as photovoltaics,photonics,and optoelectronics.Extensive efforts on the controlled synthesis of perovskite nanostructures have been made towards potential device applications.The engineering of their band structures holds great promise in the rational tuning of the electronic and optical properties of perovskite nanostructures,which is one of the keys to achieving efficient and multifunctional optoelectronic devices.In this article,we summarize recent advances in band structure engineering of perovskite nanostructures.A survey of bandgap engineering of nanostructured perovskites is firstly presented from the aspects of dimensionality tailoring,compositional substitution,phase segregation and transition,as well as strain and pressure stimuli.The strategies of electronic doping are then reviewed,including defect-induced self-doping,inorganic or organic molecules-based chemical doping,and modification by metal ions or nanostructures.Based on the bandgap engineering and electronic doping,discussions on engineering energy band alignments in perovskite nanostructures are provided for building high-performance perovskite p-n junctions and heterostructures.At last,we provide our perspectives in engineering band structures of perovskite nanostructures towards future low-energy optoelectronics technologies.
基金supported by the National Natural Science Foundation of China(U21A2078)Natural Science Foundation of Fujian Province(2020J06021,2019J01057,and 2020J01064)Scientific Research Funds of Huaqiao University.
文摘Quasi-2D perovskites have attracted tremendous interest for application as lightemission layers in light-emitting diodes(LEDs).However,the heterogeneous n phase and non-uniform distribution still severely limit the further development of quasi-2D perovskite LEDs(Pero-LEDs).Meanwhile,the increased defect density caused by the reduced dimension and grain size induces non-radiative recombination and further deteriorates the device performance.Here,we found that a series of molecules containing phosphoryl chloride functional groups have noticeable enhancement effects on the device performance of quasi-2D Pero-LEDs.Then,we studied the modification mechanism by focusing on the bis(2-oxo-3-oxazolidinyl)phosphinic chloride(BOPCl).It is concluded that the BOPCl can not only regulate the phase distribution by decreasing the crystallization rate but also remain in the grain boundaries and passivate the defects.As a result,the corresponding quasi-2D Pero-LEDs obtained a maximum external quantum efficiency(EQE_(max))of 20.82%and an average EQE(EQE_(ave))of around 20%on the optimal 50 devices,proving excellent reproducibility.Our work provides a new selection of molecular types for regulating the crystallization and passivating the defects of quasi-2D perovskite films.
基金supported by The Science and Technology Development Fund,Macao SAR(File No.0037/2018/A1,0026/2020/AGJ)MultiYear Research Grant funded by University of Macao(File No.MYRG2017-00089-FST,MYRG2018-00063-IAPME)。
文摘The wearable sensors have recently attracted considerable attentions as communication interfaces through the information perception,decoding,and conveying process.However,it is still challenging to obtain a sensor that can convert detectable signals into multiple outputs for convenient,e cient,cryptic,and high-capacity information transmission.Herein,we present a capacitive sensor of magnetic field based on a tilted flexible micromagnet array(t-FMA)as the proposed interaction interface.With the bidirectional bending capability of t-FMA actuated by magnetic torque,the sensor can recognize both the magnitude and orientation of magnetic field in real time with non-overlapping capacitance signals.The optimized sensor exhibits the high sensitivity of over 1.3 T-1 and detection limit down to 1 mT with excellent durability.As a proof of concept,the sensor has been successfully demonstrated for convenient,e cient,and programmable interaction systems,e.g.,touchless Morse code and Braille communication.The distinguishable recognition of the magnetic field orientation and magnitude further enables the sensor unit as a high-capacity transmitter for cryptic information interaction(e.g.,encoded ID recognition)and multi-control instruction outputting.We believe that the proposed magnetic field sensor can open up a potential avenue for future applications including information communication,virtual reality device,and interactive robotics.
基金financially supported by the Natural Science Foundation of China (Grants 51802253, 51972172, 61705102,61904152, and 91833304)the China Postdoctoral Science Foundation (Grant 2021M692630)+6 种基金the Natural Science Basic Research Plan in Shaanxi Province of China (2019JM-326)the Joint Research Funds of Department of Science&Technology of Shaanxi Province and Northwestern Polytechnical University (No. 2020GXLH-Z-007)the Natural Science Foundation of Jiangsu Province for Distinguished Young Scholars,China (Grant BK20200034)the Young 1000 Talents Global Recruitment Program of Chinathe Jiangsu Specially Appointed Professor programthe “Six talent peaks” Project in Jiangsu Province,Chinathe Fundamental Research Funds for the Central Universities。
文摘Pb-free Sn-based perovskite solar cells(PSCs) have recently made inspiring progress, and power conversion efficiency(PCE) of 14.8% has been achieved. However, due to the energy-level mismatch and poor interfacial contact between commonly used hole transport layer(i.e., poly(3,4-ethylenedioxythio phene):poly(styrene sulfonate), PEDOT:PSS) and FASnI_(3) film, it is still challenging to effectively extract holes at the interface. Owing to the p-type nature of Sn-based perovskites, the efficient hole extraction is of particular significance to improve the PCE of their solar cells. In this work, for the first time, the role of chiral cations, a-methylbenzylamine(S-/R-/rac-MBA), in promoting hole transportation of FASnI_(3)-based PSCs is demonstrated. The introduction of MBAs is found to form 2D/3D film with lowdimensional structures locating at PEDOT:PSS/FASnI_(3) interface, which facilitates the energy level alignment and efficient charge transfer at the interface. Importantly, chiral-induced spin selectivity(CISS)effect of R-MBA_(2)SnI_(4)induced by chiral R-MBA cation is found to further assist the specific interfacial transport of accumulated holes. As a result, R-MBA-based PSCs achieve decent PCE of 10.73% with much suppressed hysteresis and enhanced device stability. This work opens up a new strategy to efficiently promote the interfacial extraction of accumulated charges in working PSCs.
基金supported by the Program for Guangdong Introducing Innovative and Entrepreneurial Teams (Grant No. 2017ZT07C062)Shenzhen Key Laboratory of Advanced Quantum Functional Materials and Devices (Grant No. ZDSYS20190902092905285)+4 种基金Guangdong Basic and Applied Basic Research Foundation (Grant No. 2020B1515120100)the support of China Postdoctoral Science Foundation (Grant No. 2020M682780)the financial supports from Science and Technology Development Fund, Macao SAR, China (File No. 0051/2019/AFJ)Guangdong Basic and Applied Basic Research Foundation (Guangdong-Dongguan Joint Fund No. 2020B1515120025)Guangdong–Hong Kong–Macao Joint Laboratory for Neutron Scattering Science and Technology, China (Grant No. 2019B121205003)
文摘The spin-1/2 kagome antiferromagnets are key prototype materials for studying frustrated magnetism.Three isostructural kagome antiferromagnets LnCu_(3)(OH)_(6)Cl_(3)(Ln=Gd,Tb,Dy)have been successfully synthesized by the hydrothermal method.LnCu_(3)(OH)_(6)Cl_(3) adopts space group P3m1 and features the layered Cu-kagome lattice with lanthanide Ln3+cations sitting at the center of the hexagons.Although heavy lanthanides(Ln=Gd,Tb,Dy)in LnCu_(3)(OH)_(6)Cl_(3) provide a large effective magnetic moment and ferromagnetic-like spin correlations compared to light-lanthanides(Nd,Sm,Eu)analogues,Cu-kagome holds an antiferromagnetically ordered state at around 17 K like YCu_(3)(OH)_(6)Cl_(3).
基金supported by the Science and Technology Development Fund of Macao SAR(File No.0117/2024/AMJ)University of Macao(MYRG-GRG2023-00041-FST-UMDF,MYRG-GRG2024-00121-FST,MYRG-CRG2024-00014-FST-ICI)Zhuhai UM Science&Technology Research Institute(CP-009-2024).
文摘In the realm of virtual reality(VR),haptic feedback is integral to enhance the immersive experience;yet,existing wearable devices predominantly rely on skin contact feedback,lacking options for compact and non-contact breeze-sense feedback.Herein,we propose a compact and non-contact working model piezoelectret actuator for providing a gentle and safe breeze sensation.This easy-fabricated and flexible breeze-sense generator with thickness around 1 mm generates air flow pressure up to~163 Pa,which is significantly sensed by human skin.In a typical demonstration,the breeze-sense generators array showcases its versatility by employing multiple coded modes for non-contact information transmitting.The thin thinness and good flexibility facilitate seamless integration with wearable VR setups,and the wearable arrays empower volunteers to precisely perceive the continuous and sudden breeze senses in the virtual environments.This work is expected to inspire developing new haptic feedback devices that play pivotal roles in human-machine interfaces for VR applications.
