The development of quantum materials for single-photon emission is crucial for the advancement of quantum information technology.Although significant advancements have been witnessed in recent years for single-photon ...The development of quantum materials for single-photon emission is crucial for the advancement of quantum information technology.Although significant advancements have been witnessed in recent years for single-photon sources in the near-infrared band(λ∼700–1000 nm),several challenges have yet to be addressed for ideal single-photon emission at the telecommunication band.In this study,we present a droplet-epitaxy strategy for O-band to C-band single-photon source-based semiconductor quantum dots(QDs)using metal-organic vaporphase epitaxy(MOVPE).By investigating the growth conditions of the epitaxial process,we have successfully synthesized InAs/InP QDs with narrow emission lines spanning a broad spectral range of λ∼1200–1600 nm.The morphological and optical properties of the samples were characterized using atomic force microscopy and microphotoluminescence spectroscopy.The recorded single-photon purity of a plain QD structure reaches g^((2))(0)=0.16,with a radiative recombination lifetime as short as 1.5 ns.This work provides a crucial platform for future research on integrated microcavity enhancement techniques and coupled QDs with other quantum photonics in the telecom bands,offering significant prospects for quantum network applications.展开更多
Abnormal tendons are rarely ever repaired to the natural structure and morphology of normal tendons.To better guide the repair and regeneration of injured tendons through a tissue engineering method,it is necessary to...Abnormal tendons are rarely ever repaired to the natural structure and morphology of normal tendons.To better guide the repair and regeneration of injured tendons through a tissue engineering method,it is necessary to have insights into the internal morphology,organization,and composition of natural tendons.This review summarized recent researches on the structure and function of the extracellular matrix(ECM)components of tendons and highlight the application of multiple detection methodologies concerning the structure of ECMs.In addition,we look forward to the future of multi-dimensional biomaterial design methods and the potential of structural repair for tendon ECM components.In addition,focus is placed on the macro to micro detection methods for tendons,and current techniques for evaluating the extracellular matrix of tendons at the micro level are introduced in detail.Finally,emphasis is given to future extracellular matrix detection methods,as well as to how future efforts could concentrate on fabricating the biomimetic tendons.展开更多
Organic-inorganic layered perovskites are two-dimensional quantum well layers in which the layers of lead halide octahedra are stacked between the organic cation layers.The packing geometry of the soft organic molecul...Organic-inorganic layered perovskites are two-dimensional quantum well layers in which the layers of lead halide octahedra are stacked between the organic cation layers.The packing geometry of the soft organic molecules and the stiff ionic crystals induce structural deformation of the inorganic octahedra,generating complex lattice dynamics.Especially,the dielectric confinement and ionic sublattice lead to strong coupling between the photogenerated excitons and the phonons from the polar lattice which intensively affects the properties for device applications.The anharmonicity and dynamic disorder from the organic cations participate in the relaxation dynamics coupled with excitations.However,a detailed understanding of this underlying mechanism remains obscure.This work investigates the electron–optical phonon coupling dynamics by employing ultrafast pump-probe transient absorption spectroscopy.The activated different optical phonon modes are observed via systematic studies of(PEA)_(2)PbBr_(4) perovskite films on the ultrafast lattice vibrational dynamics.The experimental results indicate that solvent engineering has a significant influence on lattice vibrational modes and coherent phonon dynamics.This work provides fresh insights into electron-optical phonon coupling for emergent optoelectronics development based on layered perovskites.展开更多
High-power terahertz(THz)quantum cascade laser,as an emerging THz solid-state radiation source,is attracting attention for numerous applications including medicine,sensing,and communication.However,due to the subwavel...High-power terahertz(THz)quantum cascade laser,as an emerging THz solid-state radiation source,is attracting attention for numerous applications including medicine,sensing,and communication.However,due to the subwavelength confinement of the waveguide structure,direct beam brightness upscaling with device area remains elusive due to several mode competition and external optical lens is normally used to enhance the THz beam brightness.Here,we propose a metallic THz photonic crystal resonator with a phase-engineered design for single mode surface emission over a broad area.The quantum cascade surface-emitting laser is capable of delivering an output peak power over 185 mW with a narrow beam divergence of 4.4°×4.4°at 3.88 THz.A high beam brightness of 1.6×10^(7)W sr^(-1)m^(-2)with near-diffraction-limited M2 factors of 1.4 in both vertical and lateral directions is achieved from a large device area of 1.6×1.6 mm^(2)without using any optical lenses.The adjustable phase shift between the lattices enables a stable and high-intensity surface emission over a broad device area,which makes it an ideal light extractor for large-scale THz emitters.Our research paves the way to high brightness solid-state THz lasers and facilitates new applications in standoff THz imaging,detection,and diagnosis.展开更多
The dielectric confinement effect plays an essential role in optoelectronic devices.Existing studies on the relationship between the dielectric confinement and the photoelectric properties are inadequate.Herein,three ...The dielectric confinement effect plays an essential role in optoelectronic devices.Existing studies on the relationship between the dielectric confinement and the photoelectric properties are inadequate.Herein,three organic spacers with different dielectric constants are employed to tune the exciton dynamics of quasi-two-dimensional(quasi-2D)Ruddlesden–Popper perovskite films.Femtosecond transient absorption spectroscopy reveals that the small dielectric constant ligand enables a weak dynamic disorder and a large modulation depth of the coherent phonons,resulting in a more complete energy transfer and the inhibition of a trap-mediated nonradiative recombination.Additionally,the increase in the bulk-ligand dielectric constant reduces the corresponding exciton binding energy and then suppresses the Auger recombination,which is beneficial for high-luminance lightemitting diodes.This work emphasizes the importance of dielectric confinement for regulating the exciton dynamics of layered perovskites.展开更多
There is a rich of electric phenomena ubiquitously existing in novel quantum materials and advanced electronic devices.Microscopic understanding of the underlying physics relies on the sensitive and quantitative measu...There is a rich of electric phenomena ubiquitously existing in novel quantum materials and advanced electronic devices.Microscopic understanding of the underlying physics relies on the sensitive and quantitative measurements of the electric field,electric current,electric potential,and other related physical quantities with a spatial resolution down to nanometers.Combined with a scanning probe microscope(SPM),the emergent quantum sensors of atomic/nanometer size provide promising platforms for imaging various electric parameters with a sensitivity beyond a single electron/charge.In this perspective,we introduce the working principle of such newly developed technologies,which are based on the strong sensitivity of quantum systems to external disturbances.Then we review the recent applications of those quantum sensors in nanoscale electric sensing and imaging,including a discussion of their privileges over conventional SPM techniques.Finally,we propose some promising directions for the future developments and optimizations of quantum sensors in nanoscale electric sensing and imaging.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos.12494604,12393834,12393831,62274014,6223501662335015)the National Key R&D Program of China (Grant No.2024YFA1208900)。
文摘The development of quantum materials for single-photon emission is crucial for the advancement of quantum information technology.Although significant advancements have been witnessed in recent years for single-photon sources in the near-infrared band(λ∼700–1000 nm),several challenges have yet to be addressed for ideal single-photon emission at the telecommunication band.In this study,we present a droplet-epitaxy strategy for O-band to C-band single-photon source-based semiconductor quantum dots(QDs)using metal-organic vaporphase epitaxy(MOVPE).By investigating the growth conditions of the epitaxial process,we have successfully synthesized InAs/InP QDs with narrow emission lines spanning a broad spectral range of λ∼1200–1600 nm.The morphological and optical properties of the samples were characterized using atomic force microscopy and microphotoluminescence spectroscopy.The recorded single-photon purity of a plain QD structure reaches g^((2))(0)=0.16,with a radiative recombination lifetime as short as 1.5 ns.This work provides a crucial platform for future research on integrated microcavity enhancement techniques and coupled QDs with other quantum photonics in the telecom bands,offering significant prospects for quantum network applications.
基金supported by the National Key Research and Development Program of China(2018YFC1105100)NSFC grants(81772418,81972099,81871764,82072463)+1 种基金Zhejiang Provincial Natural Science Foundation of China(LR20H060001)Fundamental Research Funds for the Central Universities.
文摘Abnormal tendons are rarely ever repaired to the natural structure and morphology of normal tendons.To better guide the repair and regeneration of injured tendons through a tissue engineering method,it is necessary to have insights into the internal morphology,organization,and composition of natural tendons.This review summarized recent researches on the structure and function of the extracellular matrix(ECM)components of tendons and highlight the application of multiple detection methodologies concerning the structure of ECMs.In addition,we look forward to the future of multi-dimensional biomaterial design methods and the potential of structural repair for tendon ECM components.In addition,focus is placed on the macro to micro detection methods for tendons,and current techniques for evaluating the extracellular matrix of tendons at the micro level are introduced in detail.Finally,emphasis is given to future extracellular matrix detection methods,as well as to how future efforts could concentrate on fabricating the biomimetic tendons.
基金supported by the National Natural Science Foundation of China(Nos.U1804261,61627818,12074104,11804084,62075058,and 11827806)Natural Science Foundation of Henan Province(No.222300420057)+1 种基金the Outstanding Youth Foundation of Henan Normal University(No.20200171)the Young Backbone Teacher Training Program in Higher Education of Henan Province(No.2019GGJS065).
文摘Organic-inorganic layered perovskites are two-dimensional quantum well layers in which the layers of lead halide octahedra are stacked between the organic cation layers.The packing geometry of the soft organic molecules and the stiff ionic crystals induce structural deformation of the inorganic octahedra,generating complex lattice dynamics.Especially,the dielectric confinement and ionic sublattice lead to strong coupling between the photogenerated excitons and the phonons from the polar lattice which intensively affects the properties for device applications.The anharmonicity and dynamic disorder from the organic cations participate in the relaxation dynamics coupled with excitations.However,a detailed understanding of this underlying mechanism remains obscure.This work investigates the electron–optical phonon coupling dynamics by employing ultrafast pump-probe transient absorption spectroscopy.The activated different optical phonon modes are observed via systematic studies of(PEA)_(2)PbBr_(4) perovskite films on the ultrafast lattice vibrational dynamics.The experimental results indicate that solvent engineering has a significant influence on lattice vibrational modes and coherent phonon dynamics.This work provides fresh insights into electron-optical phonon coupling for emergent optoelectronics development based on layered perovskites.
基金supported by the National Natural Science Foundation of China(62274014,62235016)Bejing Municipal Science&Technology Commission(Z221100002722018).
文摘High-power terahertz(THz)quantum cascade laser,as an emerging THz solid-state radiation source,is attracting attention for numerous applications including medicine,sensing,and communication.However,due to the subwavelength confinement of the waveguide structure,direct beam brightness upscaling with device area remains elusive due to several mode competition and external optical lens is normally used to enhance the THz beam brightness.Here,we propose a metallic THz photonic crystal resonator with a phase-engineered design for single mode surface emission over a broad area.The quantum cascade surface-emitting laser is capable of delivering an output peak power over 185 mW with a narrow beam divergence of 4.4°×4.4°at 3.88 THz.A high beam brightness of 1.6×10^(7)W sr^(-1)m^(-2)with near-diffraction-limited M2 factors of 1.4 in both vertical and lateral directions is achieved from a large device area of 1.6×1.6 mm^(2)without using any optical lenses.The adjustable phase shift between the lattices enables a stable and high-intensity surface emission over a broad device area,which makes it an ideal light extractor for large-scale THz emitters.Our research paves the way to high brightness solid-state THz lasers and facilitates new applications in standoff THz imaging,detection,and diagnosis.
基金National Natural Science Foundation of China(12347158,11804084,12074104,61627818,U1804261)Natural Science Foundation of Henan Province(222300420057)Young Backbone Teacher Training Program in Higher Education of Henan Province(2019GGJS065)。
文摘The dielectric confinement effect plays an essential role in optoelectronic devices.Existing studies on the relationship between the dielectric confinement and the photoelectric properties are inadequate.Herein,three organic spacers with different dielectric constants are employed to tune the exciton dynamics of quasi-two-dimensional(quasi-2D)Ruddlesden–Popper perovskite films.Femtosecond transient absorption spectroscopy reveals that the small dielectric constant ligand enables a weak dynamic disorder and a large modulation depth of the coherent phonons,resulting in a more complete energy transfer and the inhibition of a trap-mediated nonradiative recombination.Additionally,the increase in the bulk-ligand dielectric constant reduces the corresponding exciton binding energy and then suppresses the Auger recombination,which is beneficial for high-luminance lightemitting diodes.This work emphasizes the importance of dielectric confinement for regulating the exciton dynamics of layered perovskites.
基金funding provided by Shanghai Jiao Tong Universitysupported by the National Key R&D Program under Grant Nos 2021YFA1400500+2 种基金the National Natural Science Foundation of China under Grant Nos 11888101,21725302,and U22A20260the Strategic Priority Research Program of the Chinese Academy of Sciences under Grant Nos XDB28000000support from the New Cornerstone Science Foundation through the XPLORER PRIZE.
文摘There is a rich of electric phenomena ubiquitously existing in novel quantum materials and advanced electronic devices.Microscopic understanding of the underlying physics relies on the sensitive and quantitative measurements of the electric field,electric current,electric potential,and other related physical quantities with a spatial resolution down to nanometers.Combined with a scanning probe microscope(SPM),the emergent quantum sensors of atomic/nanometer size provide promising platforms for imaging various electric parameters with a sensitivity beyond a single electron/charge.In this perspective,we introduce the working principle of such newly developed technologies,which are based on the strong sensitivity of quantum systems to external disturbances.Then we review the recent applications of those quantum sensors in nanoscale electric sensing and imaging,including a discussion of their privileges over conventional SPM techniques.Finally,we propose some promising directions for the future developments and optimizations of quantum sensors in nanoscale electric sensing and imaging.
