An improvement detecting method was proposed according to the disadvantages of testing method of optical axes parallelism of shipboard photoelectrical theodolite (short for theodolite) based on image processing. Point...An improvement detecting method was proposed according to the disadvantages of testing method of optical axes parallelism of shipboard photoelectrical theodolite (short for theodolite) based on image processing. Pointolite replaced 0.2'' collimator to reduce the errors of crosshair images processing and improve the quality of image. What’s more, the high quality images could help to optimize the image processing method and the testing accuracy. The errors between the trial results interpreted by software and the results tested in dock were less than 10'', which indicated the improve method had some actual application values.展开更多
Photoelectrical response characteristics of epitaxial graphene （EG） films on Si- and C-terminated 6H-SiC, and transferred chemical vapor deposition （CVD） graphene films on Si-terminated 6H-SiC have been investigat...Photoelectrical response characteristics of epitaxial graphene （EG） films on Si- and C-terminated 6H-SiC, and transferred chemical vapor deposition （CVD） graphene films on Si-terminated 6H-SiC have been investigated. The results show that upon illumination by a xenon lamp, the photocurrent of EG grown on Si-terminated SiC significantly increases by 147.6%, while the photocurrents of EG grown on C-terminated SiC, and transferred CVD graphene on Si-terminated SiC slightly decrease by 0.5% and 2.7%, respectively. The interfacial buffer layer between EG and Si-terminated 6H-SiC is responsible for the significant photoelectrical response of EG. Its strong photoelectrical response makes it promising for optoelectronic applications.展开更多
Molybdenum disulfide （MoS2） is an earth-abundant and low-cost hydrogen evolving electrocatalyst with the potential to replace traditional noble metal catalysts. The catalytic activity can be significantly enhanced a...Molybdenum disulfide （MoS2） is an earth-abundant and low-cost hydrogen evolving electrocatalyst with the potential to replace traditional noble metal catalysts. The catalytic activity can be significantly enhanced after modification due to higher conductivity and enriched active sites. However, the underlying mechanism of the influence of the resistance of electrode material and contact resistance on the hydrogen evolution reaction （HER） process is unclear. Herein, we present a systematic study to understand the relationship between HER performance and electrode conductivity, which is bi-tuned through the electric field and photoelectrical effect. It was found that the onset overpotential consistently decreased with the increase of electrode conductivity. In addition, the reduction of the contact resistance resulted in a quicker electrochemical reaction process than enhancing the conductivity of the MoS2 nanosheet. An onset overpotential of 89 mV was achieved under 60 mW/cm^2 sunlight illumination （0.6 sun） and a simultaneous gate voltage of 3 V. These physical strategies can also be applied to other catalysts, and offer new directions to improve HER catalytic performance of semiconductor materials.展开更多
Monochiral single-walled carbon nanotubes(SWCNTs)can enable high-performance carbon-based electronic devices and integrated circuits.However,their fabrication often requires complex SWCNT purification and enrichment.H...Monochiral single-walled carbon nanotubes(SWCNTs)can enable high-performance carbon-based electronic devices and integrated circuits.However,their fabrication often requires complex SWCNT purification and enrichment.Herein,we showed that isoindigo-based polymer derivatives(PDPPIID and PFIID)directly enriched(9,8)nanotubes from as-synthesized SWCNT powders selectively and efficiently to yield high concentration(9,8)nanotube inks.The selective wrapping mechanism was elucidated by classical full-atomistic molecular dynamic(MD)simulations.Thin-film transistors(TFTs)were fabricated by depositing the SWCNT ink into device channels using aerosol jet printing.TFT performance was strongly influenced by polymer residues,the deposition condition(humidity),and ink concentration.Optimized TFTs showed excellent device-to-device uniformity with 108 on/off ratios.Further,optoelectronic transistors were fabricated,and their photoelectrical neuromorphic characteristics,storage,memory,and logic functions were characterized under the pulsed light and voltage stimulations,demonstrating excellent application potentials.展开更多
Quantum dots(QDs)can modulate the solar spectrum through the down-conversion mechanism to better match the spectral response of solar cells.Following previous work,this paper first tested the response of QD solar cell...Quantum dots(QDs)can modulate the solar spectrum through the down-conversion mechanism to better match the spectral response of solar cells.Following previous work,this paper first tested the response of QD solar cells to specific monochromatic light,and found that QDs can effectively improve the photoelectric conversion efficiency(PCE)in the ultraviolet(UV)band by comparison.Then the photoelectric properties of the QD solar cells are tested under the air-mass 1.5(AM1.5)and air-mass 0(AM0)spectra.The experimental results show that because the absorption band of QDs is in the UV region,the space solar cells in the AM0 spectrum can obtain better PCE after coating QDs.The research results show the technical route of space solar cells with down-conversion mechanism,and put forward an important direction for the application of space solar photovoltaic(PV)technology,and have a good application prospect.展开更多
Optical synapses have an ability to perceive and remember visual information,making them expected to provide more intelligent and efficient visual solutions for humans.As a new type of artificial visual sensory device...Optical synapses have an ability to perceive and remember visual information,making them expected to provide more intelligent and efficient visual solutions for humans.As a new type of artificial visual sensory devices,photoelectric memristors can fully simulate synaptic performance and have great prospects in the development of biological vision.However,due to the urgent problems of nonlinear conductance and high-energy consumption,its further application in high-precision control scenarios and integration is hindered.In this work,we report an optoelectronic memristor with a structure of TiN/CeO_(2)/ZnO/ITO/Mica,which can achieve minimal energy consumption(187 pJ)at a single pulse(0.5 V,5 ms).Under the stimulation of continuous pulses,linearity can be achieved up to 99.6%.In addition,the device has a variety of synaptic functions under the combined action of photoelectric,which can be used for advanced vision.By utilizing its typical long-term memory characteristics,we achieved image recognition and long-term memory in a 3×3 synaptic array and further achieved female facial feature extraction behavior with an activation rate of over 92%.Moreover,we also use the linear response characteristic of the device to design and implement the night meeting behavior of autonomous vehicles based on the hardware platform.This work highlights the potential of photoelectric memristors for advancing neuromorphic vision systems,offering a new direction for bionic eyes and visual automation technology.展开更多
The presence of SnZn-related defects in Cu_(2)ZnSn(S,Se)_(4)(CZTSSe)absorber results in large irreversible energy loss and extra irreversible electron-hole non-radiative recombination,thus hindering the efficiency enh...The presence of SnZn-related defects in Cu_(2)ZnSn(S,Se)_(4)(CZTSSe)absorber results in large irreversible energy loss and extra irreversible electron-hole non-radiative recombination,thus hindering the efficiency enhancement of CZTSSe devices.Although the incorporation of Ag in CZTSSe can effectively suppress the SnZn-related defects and significantly improve the resulting cell performance,an excellent efficiency has not been achieved to date primarily owing to the poor electrical-conductivity and the low carrier density of the CZTSSe film induced by Ag substitution.Herein,this study exquisitely devises an Ag/H co-doping strategy in CZTSSe absorber via Ag substitution programs followed by hydrogen-plasma treatment procedure to suppress SnZn defects for achieving efficient CZTSSe devices.In-depth investigation results demonstrate that the incorporation of H in Ag-based CZTSSe absorber is expected to improve the poor electrical-conductivity and the low carrier density caused by Ag substitution.Importantly,the C=O and O-H functional groups induced by hydrogen incorporation,serving as an electron donor,can interact with under-coordinated cations in CZTSSe material,effectively passivating the SnZn-related defects.Consequently,the incorporation of an appropriate amount of Ag/H in CZTSSe mitigates carrier non-radiative recombination,prolongs minority carrier lifetime,and thus yields a champion efficiency of 14.74%,showing its promising application in kesterite-based CZTSSe devices.展开更多
This paper presents a novel design for a Dyson-Harrop CubeSat aimed at harvesting energy from the solar wind. Unlike current photovoltaic-based satellite energy generation, the Dyson-Harrop satellite generates energy ...This paper presents a novel design for a Dyson-Harrop CubeSat aimed at harvesting energy from the solar wind. Unlike current photovoltaic-based satellite energy generation, the Dyson-Harrop satellite generates energy based on the photoelectric effect, which has the potential to achieve significantly higher efficiency than current photovoltaic technology. The proposed CubeSat system consists of three main components: a tether unit, an energy harvesting unit, and the central 3U CubeSat body. The tether unit generates a cylindrical magnetic field along its main tether,effectively concentrating electrons from the solar wind to the energy harvesting unit. The energy harvesting unit includes a spherical electron receiver, functioning as a capacitor, which attracts electrons from the solar wind, as well as an annular flat solar sail that captures photons in the solar wind to eject electrons via the photoelectric effect, resulting in an electric current in the system.The Dyson-Harrop CubeSat is shown to be highly efficient as an energy-generation system, producing approximately 1 kW of power by a 3U CubeSat. This energy can be transmitted via microwave beams to other spacecraft or ground stations on the Earth. It is important to note that this estimation is based on first-principle estimations, and thorough theoretical analysis and experimental validation are required to confirm the feasibility of the concept.展开更多
Ammonia(NH_(3))is a fundamental chemical in agriculture and an ideal hydrogen carrier.Consequently,NH_(3)synthesis strategies with high efficiency,energy conservation,environmental friendliness,and sustainability are ...Ammonia(NH_(3))is a fundamental chemical in agriculture and an ideal hydrogen carrier.Consequently,NH_(3)synthesis strategies with high efficiency,energy conservation,environmental friendliness,and sustainability are desired eminently.The nitrite(NO_(2)^(-))reduction reaction(NO_(2-)RR)to NH_(3)offers a feasibly low-energy consumption and continuable approach to replace industrial NH_(3)synthesis.Herein,polyethyleneimine(PEI)modified Au core Rh shell nanodendrites(Au@Rh-NDs)nanohybrid(Au@Rh-NDs/PEI)with branched structure is synthesized,which achieves the high NH_(3)yield(1.68 mg h^(-1)mg_(cat)^(-1))and Faradaic efficiency(FE)of 95.86%for NO_(2)^(-)-RR at-0.39 V potential in neutral electrolyte.Particularly,the introduction of PEI significantly enhances the electroactivity of Au@Rh-NDs at low concentration of 1 mM NaNO_(2),which originates from the enrichment function of PEI for NO_(2)^(-)-ion.In addition,the Au basement permits the sustainable solar power to expedite the NO_(2)^(-)-RR at Au@Rh-NDs/PEI owing to the localized surface plasmon resonance(LSPR)of the Au core substrate.This work may provide an admissible tactic to build excellent catalysts on account of organic molecule-mediated interfacial engineering in a variety of fields of catalysis and electrocatalysis.展开更多
To solve the problem of identification and measurement of two projectiles hitting the target at the same time,this paper proposes a projectile coordinate test method combining three photoelectric encoder detection scr...To solve the problem of identification and measurement of two projectiles hitting the target at the same time,this paper proposes a projectile coordinate test method combining three photoelectric encoder detection screens,and establishes a coordinate calculation model for two projectiles to reach the same detection screen at the same time.The design method of three photoelectric encoder detection screens and the position coordinate recognition algorithm of the blocked array photoelectric detector when projectile passing through the photoelectric encoder detection screen are studied.Using the screen projection method,the intersected linear equation of the projectile and the line laser with the main detection screen as the core coordinate plane is established,and the projectile coordinate data set formed by any two photoelectric encoder detection screens is constructed.The principle of minimum error of coordinate data set is used to determine the coordinates of two projectiles hitting the target at the same time.The rationality and feasibility of the proposed test method are verified by experiments and comparative tests.展开更多
In this paper,hierarchical ultra-thin core/shell Ni_(3)S_(2)@MoS_(2)nano-arrays with Mo atomic site grown on nickel foam(Ni_(3)S_(2)@MoS_(2)-NF)were designed and synthesized through the hydrothermal method.When they a...In this paper,hierarchical ultra-thin core/shell Ni_(3)S_(2)@MoS_(2)nano-arrays with Mo atomic site grown on nickel foam(Ni_(3)S_(2)@MoS_(2)-NF)were designed and synthesized through the hydrothermal method.When they are tested as photoelectric catalysis electrodes to anti-bacteria,the Ni_(3)S_(2)@MoS_(2)within core/shell structure exhibits about several times higher rate capability and outstanding cycling stability than traditional photocatalysts.After reacting with water and oxygen,large numbers of extracellular reactive oxygen species on the surface of Ni_(3)S_(2)@MoS_(2)are observed.These reactive oxygen species can penetrate bacterial cells,resulting in a rapid rise of intracellular reactive oxygen species in a short time.The integrity of the bacterial cell membrane is also destroyed,which can be observed in both scanning and transmission images.The synthetic primer was used to specifically label the gene fragment with antibiotic resistance,which was oxidized and eliminated after the photoelectron catalysis(PEC)reaction,proving that this material for PEC antibacterial can not only kill bacteria.Successful elimination of antibiotic-resistance gene fragments can also be achieved.展开更多
Pyroelectric materials, known for their ability to convert thermal energy into electrical signals, have garnered significant attention due to their wide-ranging applications. In this work, we report the fabrication of...Pyroelectric materials, known for their ability to convert thermal energy into electrical signals, have garnered significant attention due to their wide-ranging applications. In this work, we report the fabrication of high-performance pyroelectric photodetectors utilizing a heterostructure of carbon nanotube film(CNTF) and silver nanostructure film(Ag NSF)on a lead zirconate titanate(PZT) substrate. The resulting device exhibits an impressive broad-spectrum photoelectric response, covering wavelengths from ultraviolet to near-infrared, with a responsivity range of 0.49 V·W^(-1)–1.01 V·W^(-1) and a fast response time of 8 ms–40 ms. The enhanced photoelectric properties of the CNTF/Ag NSF/PZT composite suggest its strong potential for applications in advanced broadband photodetectors, positioning this material system as a promising candidate for next-generation optoelectronic devices.展开更多
Ultrafast electron sources, which enable high spatiotemporal resolution in time-resolved electron microscopy and scanning probe microscopy, are receiving increased attention. The most widely used method for achieving ...Ultrafast electron sources, which enable high spatiotemporal resolution in time-resolved electron microscopy and scanning probe microscopy, are receiving increased attention. The most widely used method for achieving ultrafast electron sources involves irradiating metal tips by ultrashort laser pulses, causing electron beam emission via the photoelectric effect [including photon-driven(quantum) or field-driven(classical) emission]. However, the thermionic electrons emission process due to the heating effect of ultrashort lasers, particularly its dynamic aspects, has rarely been addressed in previous studies. In this paper, we improved the signal-to-noise ratio of a two-pulse correlation measurement on the tip electron emission by nearly two orders of magnitude using a delay time modulation method. This allowed us to obtain information on the temperature evolution of hot electrons and phonons in a non-equilibrium state, and to extract characteristic time scales for electron-phonon and phonon-phonon scattering. Our findings indicate that the thermionic electrons emission, unlike the instantaneous photoelectric effect, causes electron emission to lag behind the laser pulse by tens of picoseconds, thus significantly affecting the detection of ultrafast dynamics of samples. Furthermore, such a lagging effect was found to be sensitive to the local structure of the metal tip, offering new insights into the improved design of ultrafast electron sources.展开更多
Organic-inorganic hybrid metal halide perovskite solar cells(PSCs)have attracted much attention due to their high photoelectric conversion efficiency(PCE)and low cost.The certificated PCE of small active area(below 0....Organic-inorganic hybrid metal halide perovskite solar cells(PSCs)have attracted much attention due to their high photoelectric conversion efficiency(PCE)and low cost.The certificated PCE of small active area(below 0.1 cm^(2))device has reached 26.7%[1].However,when considering the scaled-up commercialization of PSCs,an obvious efficiency drop exists for the translation to large-area perovskite submodules(PSMs)with areas more than 200 cm^(2),thus limiting the practical commercialization[2].The major PCE gap between small area cells and large area modules arises the drop of open-circuit voltage(VOC)and fill factor(FF).Formamidinium lead iodide(FAPbI_(3))is now the mostly widely used and highly efficient perovskite composition.However,the photo-active black α-FAPbI_(3) phase will spontaneously transform into photo-inactive yellowδ-FAPbI_(3) phase at room temperature[3].展开更多
Multiwalled carbon nanotubes (MWCNTs) mixed in poly(3-hexylthiophene) (P3HT) were used as a photoactive layer for organic solar cells (OSC). The flexible OSCs of a structure of PET/rGO-P3HT/P3CT/PCBM/LiF-Al were prepa...Multiwalled carbon nanotubes (MWCNTs) mixed in poly(3-hexylthiophene) (P3HT) were used as a photoactive layer for organic solar cells (OSC). The flexible OSCs of a structure of PET/rGO-P3HT/P3CT/PCBM/LiF-Al were prepared by spincoating. The UV-Vis absorption spectra of the photoactive films and current-voltage characteristics of the OSCs showed the advantage of the composite devices above the pristine-polymeric ones. Under illumination of light with a 100 mW/cm<sup>2</sup>-powerdensity, the photoelectrical conversion efficiency (PCE) of the OSCs with 3.0 wt% MWNCTs embedded in the photoactive layer possess a value as large as 2.35%. The obtained results suggest further useful applications of the flexible large-area solar cells.展开更多
Neuromorphic computing simulates the operation of biological brain function for information processing and can potentially solve the bottleneck of the von Neumann architecture.This computing is realized based on memri...Neuromorphic computing simulates the operation of biological brain function for information processing and can potentially solve the bottleneck of the von Neumann architecture.This computing is realized based on memristive hardware neural networks in which synaptic devices that mimic biological synapses of the brain are the primary units.Mimicking synaptic functions with these devices is critical in neuromorphic systems.In the last decade,electrical and optical signals have been incorporated into the synaptic devices and promoted the simulation of various synaptic functions.In this review,these devices are discussed by categorizing them into electrically stimulated,optically stimulated,and photoelectric synergetic synaptic devices based on stimulation of electrical and optical signals.The working mechanisms of the devices are analyzed in detail.This is followed by a discussion of the progress in mimicking synaptic functions.In addition,existing application scenarios of various synaptic devices are outlined.Furthermore,the performances and future development of the synaptic devices that could be significant for building efficient neuromorphic systems are prospected.展开更多
Eu-doped Ce:YAG single crystal(SC) was fabricated by the Czochralski method. The crystal structure,optical and photoelectric property of the constructed w-LED was investigated. The XRD and HRTEM results show that YAG ...Eu-doped Ce:YAG single crystal(SC) was fabricated by the Czochralski method. The crystal structure,optical and photoelectric property of the constructed w-LED was investigated. The XRD and HRTEM results show that YAG crystal structure has little change when Eu^(3+), Ce^(3+) are doped. Absorption spectra and photoluminescence spectra show that the Ce,Eu:YAG single crystal can effectively absorb the 460 nm blue light to form a broadband emission center at 530 nm, decay curves of the crystal show that the energy transfer between Ce^(3+) and Eu^(3+) is highly suppressed. Compared with commercial Ce:YAG phosphor, Ce,Eu:YAG exhibits better thermal stability.展开更多
The measurement and control of high temperature play very important roles in national defense,military,scientific experiments,industrial and agricultural production.Photoelectric pyrometer is one of the important radi...The measurement and control of high temperature play very important roles in national defense,military,scientific experiments,industrial and agricultural production.Photoelectric pyrometer is one of the important radiation thermometers for non-contact temperature measurement.It has an important application in the field of high temperature measurement,and its performance directly affects the accuracy of temperature measurement.By improving the design of the detection optical system of the photoelectric pyrometer,the imaging performance of the photoelectric pyrometer can be improved effectively,and the temperature measurement accuracy can be improved.In this paper,the temperature measurement principle of photoelectric pyrometer,the wo rking principle of the detection optical system and the composition of the system are introduced.The optical components that affect the imaging of the optical system of the photoelectric pyrometer are analyzed.The optical pyrometer detection optical system is simulated by ZEMAX software,based on the analysis results,the Modulation Transfer Function(MTF)and the spot Diagram are used as the main evaluation criteria to optimize the design of the objective lens of the photoelectric pyrometer detection optical system.The imaging performance of the photoelectric pyrometer detection optical system and the accuracy of temperature measurement of the photoelectric pyrometer are improved by optimization design of the detection optical system.展开更多
The measurement of the rolling angle of the projectile is one of the key technologies for the terminal correction projectile.To improve the resolution accuracy of the rolling angle in the laser seeker weapon system, t...The measurement of the rolling angle of the projectile is one of the key technologies for the terminal correction projectile.To improve the resolution accuracy of the rolling angle in the laser seeker weapon system, the imaging model of the detector, calculation model of the position and the signal-to-noise ratio(SNR) model of the circuit are built to derive both the correlation between the resolution error of the rolling angle and the spot position, and the relation between the position resolution error and the SNR. Then the influence of each parameter on the SNR is analyzed at large,and the parameters of the circuit are determined. Meanwhile, the SNR and noise voltage of the circuit are calculated according to the SNR model and the decay model of the laser energy. Finally,the actual photoelectric detection circuit is built, whose SNR is measured to be up to 53 d B. It can fully meet the requirement of0.5° for the resolution error of the rolling angle, thereby realizing the analysis of critical technology for photoelectric detection of laser seeker signals.展开更多
As semiconductor devices,the terahertz quantum-cascade laser is a coherent source based on intersubband transitions of unipolar carriers while the terahertz quantum-well photodetector is a kind of detector which match...As semiconductor devices,the terahertz quantum-cascade laser is a coherent source based on intersubband transitions of unipolar carriers while the terahertz quantum-well photodetector is a kind of detector which matches the laser frequency.They are solid-state,electrically operated,and can be easily integrated with other components.This paper reviews the state of the art for the design,working performance,and future directions of the two devices.Their applications in photoelectric characterization and imaging are also discussed.展开更多
文摘An improvement detecting method was proposed according to the disadvantages of testing method of optical axes parallelism of shipboard photoelectrical theodolite (short for theodolite) based on image processing. Pointolite replaced 0.2'' collimator to reduce the errors of crosshair images processing and improve the quality of image. What’s more, the high quality images could help to optimize the image processing method and the testing accuracy. The errors between the trial results interpreted by software and the results tested in dock were less than 10'', which indicated the improve method had some actual application values.
基金the Program for New Century Excellent Talents in University of Ministry of Education of China(Grant No.NCET-10-0291)the Startup Research Project of University of Electronic Science and Technology of China(Grant No.Y02002010301041)
文摘Photoelectrical response characteristics of epitaxial graphene （EG） films on Si- and C-terminated 6H-SiC, and transferred chemical vapor deposition （CVD） graphene films on Si-terminated 6H-SiC have been investigated. The results show that upon illumination by a xenon lamp, the photocurrent of EG grown on Si-terminated SiC significantly increases by 147.6%, while the photocurrents of EG grown on C-terminated SiC, and transferred CVD graphene on Si-terminated SiC slightly decrease by 0.5% and 2.7%, respectively. The interfacial buffer layer between EG and Si-terminated 6H-SiC is responsible for the significant photoelectrical response of EG. Its strong photoelectrical response makes it promising for optoelectronic applications.
文摘Molybdenum disulfide （MoS2） is an earth-abundant and low-cost hydrogen evolving electrocatalyst with the potential to replace traditional noble metal catalysts. The catalytic activity can be significantly enhanced after modification due to higher conductivity and enriched active sites. However, the underlying mechanism of the influence of the resistance of electrode material and contact resistance on the hydrogen evolution reaction （HER） process is unclear. Herein, we present a systematic study to understand the relationship between HER performance and electrode conductivity, which is bi-tuned through the electric field and photoelectrical effect. It was found that the onset overpotential consistently decreased with the increase of electrode conductivity. In addition, the reduction of the contact resistance resulted in a quicker electrochemical reaction process than enhancing the conductivity of the MoS2 nanosheet. An onset overpotential of 89 mV was achieved under 60 mW/cm^2 sunlight illumination （0.6 sun） and a simultaneous gate voltage of 3 V. These physical strategies can also be applied to other catalysts, and offer new directions to improve HER catalytic performance of semiconductor materials.
基金supported by the National Key Research and Development Program of China(No.2020YFA0714700)the National Natural Science Foundation of China(No.61874132)+5 种基金Key Research Program of Frontier Science of Chinese Academy of Sciences(No.QYZDB-SSWSLH031)the Shaanxi Province Natural Science Foundation(No.2017JM5063)Cooperation Project of Vacuum Interconnect Nano X Research Facility(No.NANO-X)of Suzhou nanotechnology and Nano-Bionics Institute,Chinese Academy of Sciences(No.E20045)China scholarship fund(No.201708615046)Y.C.acknowledges the Australian Research Council under the Future Fellowships scheme(No.FT160100107)M.T.thanks Prof.T.Okazaki(National Institute of Advanced Industrial Science and Technology)for experimental help.
文摘Monochiral single-walled carbon nanotubes(SWCNTs)can enable high-performance carbon-based electronic devices and integrated circuits.However,their fabrication often requires complex SWCNT purification and enrichment.Herein,we showed that isoindigo-based polymer derivatives(PDPPIID and PFIID)directly enriched(9,8)nanotubes from as-synthesized SWCNT powders selectively and efficiently to yield high concentration(9,8)nanotube inks.The selective wrapping mechanism was elucidated by classical full-atomistic molecular dynamic(MD)simulations.Thin-film transistors(TFTs)were fabricated by depositing the SWCNT ink into device channels using aerosol jet printing.TFT performance was strongly influenced by polymer residues,the deposition condition(humidity),and ink concentration.Optimized TFTs showed excellent device-to-device uniformity with 108 on/off ratios.Further,optoelectronic transistors were fabricated,and their photoelectrical neuromorphic characteristics,storage,memory,and logic functions were characterized under the pulsed light and voltage stimulations,demonstrating excellent application potentials.
基金supported by the Science&Technology Development Fund of Tianjin Education Commission for Higher Education(No.2022KJ133).
文摘Quantum dots(QDs)can modulate the solar spectrum through the down-conversion mechanism to better match the spectral response of solar cells.Following previous work,this paper first tested the response of QD solar cells to specific monochromatic light,and found that QDs can effectively improve the photoelectric conversion efficiency(PCE)in the ultraviolet(UV)band by comparison.Then the photoelectric properties of the QD solar cells are tested under the air-mass 1.5(AM1.5)and air-mass 0(AM0)spectra.The experimental results show that because the absorption band of QDs is in the UV region,the space solar cells in the AM0 spectrum can obtain better PCE after coating QDs.The research results show the technical route of space solar cells with down-conversion mechanism,and put forward an important direction for the application of space solar photovoltaic(PV)technology,and have a good application prospect.
基金supported by Science and Technology Project of Hebei Education Department(grant no.QN2023092)High-level Talent Research Startup Project of Hebei University(grant no.521100221071,521000981426,521100223225)+17 种基金National Key R&D Plan"Nano Frontier"Key Special Project(Grant Nos.2024YFA1208400,2021YFA1200502)National Key R&D Program Disruptive Technology Innovation Project(Grant No.2024YFF1504300)National Natural Science Foundation of China(Grant Nos.62004056,62104058,Grant No.61874158)National Major R&D Project Cultivation Projects(Grant No.92164109)Natural Science Foundation of Hebei Province(Grant Nos.F2021201045,F2021201022,F2022201054,F2023201044,F2022201002)Special Support Funds for National High-Level Talents(Grant No.041500120001)Hebei Province Yanzhao Young Scientist Project(Grant No.F2023201076)Support Program for the Top Young Talents of Hebei Province(Grant No.70280011807)Hebei Province High-Level Talent Funding Project(Grant No.B20231003)Strategic Leading Science and Technology Special Project of Chinese Academy of Sciences(Grant No.XDB44000000-7)Interdisciplinary Research Program of Natural Science of Hebei University(Grant No.DXK202101)Institute of Life Sciences and Green Development(Grant No.521100311)Outstanding Young Scientific Research and Innovation Team of Hebei University(Grant No.605020521001)Advanced Talents Incubation Program of Hebei University(Grant Nos.521000981426,521100221071,521100224232,521000981363)Science and Technology Project of Hebei Education Department(Grant Nos.QN2020178,QN2021026)Baoding Science and Technology Plan Project(Grant No.2172P011)Hebei Province Key R&D Plan Projects(Grant No.22311101D)Baoding Science and Technology Plan Project(Grant No.2272P014)Regional Innovation and Development Joint Fund Key Project(Grant No.U23A20365)Hebei Province Natural Science Foundation(Grant No.F2023201044).
文摘Optical synapses have an ability to perceive and remember visual information,making them expected to provide more intelligent and efficient visual solutions for humans.As a new type of artificial visual sensory devices,photoelectric memristors can fully simulate synaptic performance and have great prospects in the development of biological vision.However,due to the urgent problems of nonlinear conductance and high-energy consumption,its further application in high-precision control scenarios and integration is hindered.In this work,we report an optoelectronic memristor with a structure of TiN/CeO_(2)/ZnO/ITO/Mica,which can achieve minimal energy consumption(187 pJ)at a single pulse(0.5 V,5 ms).Under the stimulation of continuous pulses,linearity can be achieved up to 99.6%.In addition,the device has a variety of synaptic functions under the combined action of photoelectric,which can be used for advanced vision.By utilizing its typical long-term memory characteristics,we achieved image recognition and long-term memory in a 3×3 synaptic array and further achieved female facial feature extraction behavior with an activation rate of over 92%.Moreover,we also use the linear response characteristic of the device to design and implement the night meeting behavior of autonomous vehicles based on the hardware platform.This work highlights the potential of photoelectric memristors for advancing neuromorphic vision systems,offering a new direction for bionic eyes and visual automation technology.
基金supported by the National Natural Science Foundation of China(51802081,62074052,and 62104061)the Natural Science Foundation of Henan Province(232300420145).
文摘The presence of SnZn-related defects in Cu_(2)ZnSn(S,Se)_(4)(CZTSSe)absorber results in large irreversible energy loss and extra irreversible electron-hole non-radiative recombination,thus hindering the efficiency enhancement of CZTSSe devices.Although the incorporation of Ag in CZTSSe can effectively suppress the SnZn-related defects and significantly improve the resulting cell performance,an excellent efficiency has not been achieved to date primarily owing to the poor electrical-conductivity and the low carrier density of the CZTSSe film induced by Ag substitution.Herein,this study exquisitely devises an Ag/H co-doping strategy in CZTSSe absorber via Ag substitution programs followed by hydrogen-plasma treatment procedure to suppress SnZn defects for achieving efficient CZTSSe devices.In-depth investigation results demonstrate that the incorporation of H in Ag-based CZTSSe absorber is expected to improve the poor electrical-conductivity and the low carrier density caused by Ag substitution.Importantly,the C=O and O-H functional groups induced by hydrogen incorporation,serving as an electron donor,can interact with under-coordinated cations in CZTSSe material,effectively passivating the SnZn-related defects.Consequently,the incorporation of an appropriate amount of Ag/H in CZTSSe mitigates carrier non-radiative recombination,prolongs minority carrier lifetime,and thus yields a champion efficiency of 14.74%,showing its promising application in kesterite-based CZTSSe devices.
基金supported by the Discovery grant(No.RGPIN-2024-06290)the CREATE grant(No.504156)of the Natural Sciences and Engineering Research Council of Canada.
文摘This paper presents a novel design for a Dyson-Harrop CubeSat aimed at harvesting energy from the solar wind. Unlike current photovoltaic-based satellite energy generation, the Dyson-Harrop satellite generates energy based on the photoelectric effect, which has the potential to achieve significantly higher efficiency than current photovoltaic technology. The proposed CubeSat system consists of three main components: a tether unit, an energy harvesting unit, and the central 3U CubeSat body. The tether unit generates a cylindrical magnetic field along its main tether,effectively concentrating electrons from the solar wind to the energy harvesting unit. The energy harvesting unit includes a spherical electron receiver, functioning as a capacitor, which attracts electrons from the solar wind, as well as an annular flat solar sail that captures photons in the solar wind to eject electrons via the photoelectric effect, resulting in an electric current in the system.The Dyson-Harrop CubeSat is shown to be highly efficient as an energy-generation system, producing approximately 1 kW of power by a 3U CubeSat. This energy can be transmitted via microwave beams to other spacecraft or ground stations on the Earth. It is important to note that this estimation is based on first-principle estimations, and thorough theoretical analysis and experimental validation are required to confirm the feasibility of the concept.
基金supported by the National Natural Science Foundation of China(22273056)the National Training Program of Innovation and Entrepreneurship for Undergraduates(202410718010)+2 种基金the Natural Science Basic Research Project of Shaanxi Province(2024JC-YBQN-0092)the Scientific research project of Shaanxi Institute of Basic Sciences(23JHQ003)the Scientific Research Program Funded by Education Department of Shaanxi Provincial Government(23JK0694)。
文摘Ammonia(NH_(3))is a fundamental chemical in agriculture and an ideal hydrogen carrier.Consequently,NH_(3)synthesis strategies with high efficiency,energy conservation,environmental friendliness,and sustainability are desired eminently.The nitrite(NO_(2)^(-))reduction reaction(NO_(2-)RR)to NH_(3)offers a feasibly low-energy consumption and continuable approach to replace industrial NH_(3)synthesis.Herein,polyethyleneimine(PEI)modified Au core Rh shell nanodendrites(Au@Rh-NDs)nanohybrid(Au@Rh-NDs/PEI)with branched structure is synthesized,which achieves the high NH_(3)yield(1.68 mg h^(-1)mg_(cat)^(-1))and Faradaic efficiency(FE)of 95.86%for NO_(2)^(-)-RR at-0.39 V potential in neutral electrolyte.Particularly,the introduction of PEI significantly enhances the electroactivity of Au@Rh-NDs at low concentration of 1 mM NaNO_(2),which originates from the enrichment function of PEI for NO_(2)^(-)-ion.In addition,the Au basement permits the sustainable solar power to expedite the NO_(2)^(-)-RR at Au@Rh-NDs/PEI owing to the localized surface plasmon resonance(LSPR)of the Au core substrate.This work may provide an admissible tactic to build excellent catalysts on account of organic molecule-mediated interfacial engineering in a variety of fields of catalysis and electrocatalysis.
基金supported by National Natural Science Foundation of China(Grant No.62073256)Shaanxi Provincial Science and Technology Department(Grant No.2023-YBGY-342)。
文摘To solve the problem of identification and measurement of two projectiles hitting the target at the same time,this paper proposes a projectile coordinate test method combining three photoelectric encoder detection screens,and establishes a coordinate calculation model for two projectiles to reach the same detection screen at the same time.The design method of three photoelectric encoder detection screens and the position coordinate recognition algorithm of the blocked array photoelectric detector when projectile passing through the photoelectric encoder detection screen are studied.Using the screen projection method,the intersected linear equation of the projectile and the line laser with the main detection screen as the core coordinate plane is established,and the projectile coordinate data set formed by any two photoelectric encoder detection screens is constructed.The principle of minimum error of coordinate data set is used to determine the coordinates of two projectiles hitting the target at the same time.The rationality and feasibility of the proposed test method are verified by experiments and comparative tests.
基金supported by the Fund of AHBMC-AHU Joint Laboratory of Biomedical Material(No.2022340102000659)the 512 Talent Cultivation Plan of Bengbu Medical College(No.51201313)+1 种基金the Young Scientist Fund of Bengbu Medical College(No.2021byyfyyq02)the Scientific Research Fund of Anhui Provincial Education Department(No.2023AH040290).
文摘In this paper,hierarchical ultra-thin core/shell Ni_(3)S_(2)@MoS_(2)nano-arrays with Mo atomic site grown on nickel foam(Ni_(3)S_(2)@MoS_(2)-NF)were designed and synthesized through the hydrothermal method.When they are tested as photoelectric catalysis electrodes to anti-bacteria,the Ni_(3)S_(2)@MoS_(2)within core/shell structure exhibits about several times higher rate capability and outstanding cycling stability than traditional photocatalysts.After reacting with water and oxygen,large numbers of extracellular reactive oxygen species on the surface of Ni_(3)S_(2)@MoS_(2)are observed.These reactive oxygen species can penetrate bacterial cells,resulting in a rapid rise of intracellular reactive oxygen species in a short time.The integrity of the bacterial cell membrane is also destroyed,which can be observed in both scanning and transmission images.The synthetic primer was used to specifically label the gene fragment with antibiotic resistance,which was oxidized and eliminated after the photoelectron catalysis(PEC)reaction,proving that this material for PEC antibacterial can not only kill bacteria.Successful elimination of antibiotic-resistance gene fragments can also be achieved.
基金Project supported in part by the Open Research Fund Program of the State Key Laboratory of Low-Dimensional Quantum Physics (Grant No. KF202007)the NSAF (Grant No. U1730246)。
文摘Pyroelectric materials, known for their ability to convert thermal energy into electrical signals, have garnered significant attention due to their wide-ranging applications. In this work, we report the fabrication of high-performance pyroelectric photodetectors utilizing a heterostructure of carbon nanotube film(CNTF) and silver nanostructure film(Ag NSF)on a lead zirconate titanate(PZT) substrate. The resulting device exhibits an impressive broad-spectrum photoelectric response, covering wavelengths from ultraviolet to near-infrared, with a responsivity range of 0.49 V·W^(-1)–1.01 V·W^(-1) and a fast response time of 8 ms–40 ms. The enhanced photoelectric properties of the CNTF/Ag NSF/PZT composite suggest its strong potential for applications in advanced broadband photodetectors, positioning this material system as a promising candidate for next-generation optoelectronic devices.
基金supported by the National Key R&D Program under Grant No.2021YFA1400500the National Natural Science Foundation of China under Grant No.22273029+1 种基金the New Cornerstone Science Foundation through the New Cornerstone Investigator Program under Grant No.NCI202303 and the XPLORER PRIZEthe Beijing Outstanding Young Scientist Program under Grant No.JWZQ20240101002。
文摘Ultrafast electron sources, which enable high spatiotemporal resolution in time-resolved electron microscopy and scanning probe microscopy, are receiving increased attention. The most widely used method for achieving ultrafast electron sources involves irradiating metal tips by ultrashort laser pulses, causing electron beam emission via the photoelectric effect [including photon-driven(quantum) or field-driven(classical) emission]. However, the thermionic electrons emission process due to the heating effect of ultrashort lasers, particularly its dynamic aspects, has rarely been addressed in previous studies. In this paper, we improved the signal-to-noise ratio of a two-pulse correlation measurement on the tip electron emission by nearly two orders of magnitude using a delay time modulation method. This allowed us to obtain information on the temperature evolution of hot electrons and phonons in a non-equilibrium state, and to extract characteristic time scales for electron-phonon and phonon-phonon scattering. Our findings indicate that the thermionic electrons emission, unlike the instantaneous photoelectric effect, causes electron emission to lag behind the laser pulse by tens of picoseconds, thus significantly affecting the detection of ultrafast dynamics of samples. Furthermore, such a lagging effect was found to be sensitive to the local structure of the metal tip, offering new insights into the improved design of ultrafast electron sources.
基金support from open fund of Fujian Provincial Key Laboratory of Functional Materials and Applications(Xiamen University of Technology,fma2024003)the National Key R&D Program of China(No.2021YFB3500400)the National Natural Science Foundation of China(Nos.52073286 and 22275185).
文摘Organic-inorganic hybrid metal halide perovskite solar cells(PSCs)have attracted much attention due to their high photoelectric conversion efficiency(PCE)and low cost.The certificated PCE of small active area(below 0.1 cm^(2))device has reached 26.7%[1].However,when considering the scaled-up commercialization of PSCs,an obvious efficiency drop exists for the translation to large-area perovskite submodules(PSMs)with areas more than 200 cm^(2),thus limiting the practical commercialization[2].The major PCE gap between small area cells and large area modules arises the drop of open-circuit voltage(VOC)and fill factor(FF).Formamidinium lead iodide(FAPbI_(3))is now the mostly widely used and highly efficient perovskite composition.However,the photo-active black α-FAPbI_(3) phase will spontaneously transform into photo-inactive yellowδ-FAPbI_(3) phase at room temperature[3].
文摘Multiwalled carbon nanotubes (MWCNTs) mixed in poly(3-hexylthiophene) (P3HT) were used as a photoactive layer for organic solar cells (OSC). The flexible OSCs of a structure of PET/rGO-P3HT/P3CT/PCBM/LiF-Al were prepared by spincoating. The UV-Vis absorption spectra of the photoactive films and current-voltage characteristics of the OSCs showed the advantage of the composite devices above the pristine-polymeric ones. Under illumination of light with a 100 mW/cm<sup>2</sup>-powerdensity, the photoelectrical conversion efficiency (PCE) of the OSCs with 3.0 wt% MWNCTs embedded in the photoactive layer possess a value as large as 2.35%. The obtained results suggest further useful applications of the flexible large-area solar cells.
基金This work was supported by the National Natural Science Foundation of China(11804166,U1732126,51872145)the China Postdoctoral Science Foundation(2018M630587)+1 种基金the Natural Science Foundation of Jiangsu Province(BK20200760,BK20191472)the Introduction of Talents Project of Nanjing University of Posts and Telecommunications(NY220097).
文摘Neuromorphic computing simulates the operation of biological brain function for information processing and can potentially solve the bottleneck of the von Neumann architecture.This computing is realized based on memristive hardware neural networks in which synaptic devices that mimic biological synapses of the brain are the primary units.Mimicking synaptic functions with these devices is critical in neuromorphic systems.In the last decade,electrical and optical signals have been incorporated into the synaptic devices and promoted the simulation of various synaptic functions.In this review,these devices are discussed by categorizing them into electrically stimulated,optically stimulated,and photoelectric synergetic synaptic devices based on stimulation of electrical and optical signals.The working mechanisms of the devices are analyzed in detail.This is followed by a discussion of the progress in mimicking synaptic functions.In addition,existing application scenarios of various synaptic devices are outlined.Furthermore,the performances and future development of the synaptic devices that could be significant for building efficient neuromorphic systems are prospected.
基金Project supported by the National Natural Science Foundation of China(51372172,51672192)
文摘Eu-doped Ce:YAG single crystal(SC) was fabricated by the Czochralski method. The crystal structure,optical and photoelectric property of the constructed w-LED was investigated. The XRD and HRTEM results show that YAG crystal structure has little change when Eu^(3+), Ce^(3+) are doped. Absorption spectra and photoluminescence spectra show that the Ce,Eu:YAG single crystal can effectively absorb the 460 nm blue light to form a broadband emission center at 530 nm, decay curves of the crystal show that the energy transfer between Ce^(3+) and Eu^(3+) is highly suppressed. Compared with commercial Ce:YAG phosphor, Ce,Eu:YAG exhibits better thermal stability.
基金Jilin Province Science and Technology Development Plan Project(20190701024GH)。
文摘The measurement and control of high temperature play very important roles in national defense,military,scientific experiments,industrial and agricultural production.Photoelectric pyrometer is one of the important radiation thermometers for non-contact temperature measurement.It has an important application in the field of high temperature measurement,and its performance directly affects the accuracy of temperature measurement.By improving the design of the detection optical system of the photoelectric pyrometer,the imaging performance of the photoelectric pyrometer can be improved effectively,and the temperature measurement accuracy can be improved.In this paper,the temperature measurement principle of photoelectric pyrometer,the wo rking principle of the detection optical system and the composition of the system are introduced.The optical components that affect the imaging of the optical system of the photoelectric pyrometer are analyzed.The optical pyrometer detection optical system is simulated by ZEMAX software,based on the analysis results,the Modulation Transfer Function(MTF)and the spot Diagram are used as the main evaluation criteria to optimize the design of the objective lens of the photoelectric pyrometer detection optical system.The imaging performance of the photoelectric pyrometer detection optical system and the accuracy of temperature measurement of the photoelectric pyrometer are improved by optimization design of the detection optical system.
基金supported by the National Natural Science Foundation of China(61201391)
文摘The measurement of the rolling angle of the projectile is one of the key technologies for the terminal correction projectile.To improve the resolution accuracy of the rolling angle in the laser seeker weapon system, the imaging model of the detector, calculation model of the position and the signal-to-noise ratio(SNR) model of the circuit are built to derive both the correlation between the resolution error of the rolling angle and the spot position, and the relation between the position resolution error and the SNR. Then the influence of each parameter on the SNR is analyzed at large,and the parameters of the circuit are determined. Meanwhile, the SNR and noise voltage of the circuit are calculated according to the SNR model and the decay model of the laser energy. Finally,the actual photoelectric detection circuit is built, whose SNR is measured to be up to 53 d B. It can fully meet the requirement of0.5° for the resolution error of the rolling angle, thereby realizing the analysis of critical technology for photoelectric detection of laser seeker signals.
基金the National Key R&D Program of China(Grant No.2017YFA0701005)the National Natural Science Foundation of China(Grant Nos.61927813,61775229,61704181,and 61991432)the Shanghai International Cooperation Project,China(Grant No.18590780100).
文摘As semiconductor devices,the terahertz quantum-cascade laser is a coherent source based on intersubband transitions of unipolar carriers while the terahertz quantum-well photodetector is a kind of detector which matches the laser frequency.They are solid-state,electrically operated,and can be easily integrated with other components.This paper reviews the state of the art for the design,working performance,and future directions of the two devices.Their applications in photoelectric characterization and imaging are also discussed.
