The nano-patterned InGaN film was used in green InGaN/GaN multiple quantum wells(MQWs)structure,to relieve the unpleasantly existing mismatch between high indium content InGaN and GaN,as well as to enhance the light o...The nano-patterned InGaN film was used in green InGaN/GaN multiple quantum wells(MQWs)structure,to relieve the unpleasantly existing mismatch between high indium content InGaN and GaN,as well as to enhance the light output.The different self-assembled nano-masks were formed on InGaN by annealing thin Ni layers of different thicknesses.Whereafter,the InGaN films were etched into nano-patterned films.Compared with the green MQWs structure grown on untreated InGaN film,which on nano-patterned InGaN had better luminous performance.Among them the MQWs performed best when 3 nm thick Ni film was used as mask,because that optimally balanced the effects of nano-patterned InGaN on the crystal quality and the light output.展开更多
Until very recently, gallium oxide(Ga_2O_3) has aroused more and more interests in the area of power electronics due to its ultra-wide bandgap of 4.5–4.8 eV, estimated critical field of 8 MV/cm and decent intrinsic e...Until very recently, gallium oxide(Ga_2O_3) has aroused more and more interests in the area of power electronics due to its ultra-wide bandgap of 4.5–4.8 eV, estimated critical field of 8 MV/cm and decent intrinsic electron mobility limit of250 cm2/(V·s), yielding a high Baliga's figures-of-merit(FOM) of more than 3000, which is several times higher than GaN and SiC.In addition to its excellent material properties, potential low-cost and large size substrate through melt-grown methodology also endows β-Ga_2O_3 more potential for future low-cost power devices. This article focuses on reviewing the most recent advances ofβ-Ga_2O_3 based power devices. It will be starting with a brief introduction to the material properties of β-Ga_2O_3 and then the growth techniques of its native substrate, followed by the thin film epitaxial growth. The performance of state-of-art β-Ga_2O_3 devices, including diodes and FETs are fully discussed and compared. Finally, potential solutions to the challenges of β-Ga_2O_3 are also discussed and explored.展开更多
Interface engineering has been regarded as an effective and noninvasive means to optimize the performance of perovskite solar cells(PSCs).Here,doping engineering of a ZnO electron transport layer(ETL)and CsPbI3/ZnO in...Interface engineering has been regarded as an effective and noninvasive means to optimize the performance of perovskite solar cells(PSCs).Here,doping engineering of a ZnO electron transport layer(ETL)and CsPbI3/ZnO interface engineering via introduction of an interfacial layer are employed to improve the performances of CsPbI3-based PSCs.The results show that when introducing a TiO2 buffer layer while increasing the ZnO layer doping concentration,the open-circuit voltage,power conversion efficiency,and fill factor of the CsPbI3-based PSCs can be improved to 1.31 V,21.06%,and 74.07%,respectively,which are superior to those of PSCs only modified by the TiO2 buffer layer or high-concentration doping of ZnO layer.On the one hand,the buffer layer relieves the band bending and structural disorder of CsPbI3.On the other hand,the increased doping concentration of the ZnO layer improves the conductivity of the TiO2/ZnO bilayer ETL because of the strong interaction between the TiO2 and ZnO layers.However,such phenomena are not observed for those of a PCBM/ZnO bilayer ETL because of the weak interlayer interaction of the PCBM/ZnO interface.These results provide a comprehensive understanding of the CsPbI3/ZnO interface and suggest a guideline to design high-performance PSCs.展开更多
A novel interface design is proposed for carbon-based,all-inorganic CsPbIBr2 perovskite solar cells(PSCs)by introducing interfacial voids between TiO2 electron transport layer and CsPbIBr2 absorber.Compared with the g...A novel interface design is proposed for carbon-based,all-inorganic CsPbIBr2 perovskite solar cells(PSCs)by introducing interfacial voids between TiO2 electron transport layer and CsPbIBr2 absorber.Compared with the general interfacial engineering strategies,this design exempts any extra modification layer in final PSC.More importantly,the interfacial voids produced by thermal decomposition of 2-phenylethylammonium iodide trigger three beneficial e ects.First,they promote the light scattering in CsPbIBr2 film and thereby boost absorption ability of the resulting CsPbIBr2 PSCs.Second,they suppress recombination of charge carriers and thus reduce dark saturation current density(J0)of the PSCs.Third,interfacial voids enlarge built-in potential(Vbi)of the PSCs,awarding increased driving force for dissociating photo-generated charge carriers.Consequently,the PSC yields the optimized e ciency of 10.20%coupled with an open-circuit voltage(Voc)of 1.338 V.The Voc achieved herein represents the best value among CsPbIBr2 PSCs reported earlier.Meanwhile,the non-encapsulated PSCs exhibit an excellent stability against light,thermal,and humidity stresses,since it remains^97%or^94%of its initial e ciency after being heated at 85℃for 12 h or stored in ambient atmosphere with relative humidity of 30–40%for 60 days,respectively.展开更多
Despite being the long-time mainstream semiconductor for both logic and power devices, Silicon is now facing its dilemma and limitation of scalability and material potential.Especially for power devices, people are de...Despite being the long-time mainstream semiconductor for both logic and power devices, Silicon is now facing its dilemma and limitation of scalability and material potential.Especially for power devices, people are demanding escalating efficiency with higher blocking voltage while its power consumption and heat generation are less. Constrained by its narrow bandgap of 1.14 eV, Silicon only has a critical breakdown field(E_c) of 0.3 MV/cm, yielding a Baliga figureof-merit(BFOM = ε×μ× E_c^3) of unity when normalized to itself. It is hence required that the dominating factor E_c should be as high as possible such that the BFOM will be hundreds or even thousands of times when compared to Silicon so as to minimize the conduction loss. Beta-Gallium Oxide(β-Ga_2O_3) with decent μ of 250 cm2/Vs, ultra-wide bandgap of4.8 eV and high critical E_c of 8 MV/cm, yielding a superior high BFOM of more than 3000. Therefore, system made withβ-Ga_2O_3 can be thinner, lighter and capable of handling more power than the one with Silicon. In addition, low-cost and large size substrate through melt-grown method endows β-Ga_2O_3 more potentials as cost-effective power devices. After resolving the low thermal conductivity issue,unipolar devices made with ultra-wide bandgap β-Ga_2O_3 are promised to make power transition and our life more efficient.展开更多
Electrochemical reduction of molecular O2 to hydrogen peroxide(H2O2)offers a promising solution for water purification and environmental remediation.Here,we design a hierarchical free-standing single-Co-atom(with Co-N...Electrochemical reduction of molecular O2 to hydrogen peroxide(H2O2)offers a promising solution for water purification and environmental remediation.Here,we design a hierarchical free-standing single-Co-atom(with Co-N4 coordination)electrode for oxygen reduction reaction(ORR)via a two-electron pathway to make H2O2 in acidic media.The current density of the single-Co-atom electrode reached 51 mA/cm2 at 0.1 V vs reversible hydrogen electrode,lasting for more than 10 hours of continuous operation with H2O2 selectivity greater than 80%.Toward practical application,the single-Co-atom electrode was directly used to assemble an electrochemical cell to produce H2O2 at a rate of 676 mol/kgcat/h with a cell voltage of about 1.6 V.展开更多
Harnessing energy from the environment promotes the rapid development of micro-power generators and relevant power management modules of alternating current (AC) line-filtering to obtain a stabilized direct current (D...Harnessing energy from the environment promotes the rapid development of micro-power generators and relevant power management modules of alternating current (AC) line-filtering to obtain a stabilized direct current (DC) output for storage and use. Micro-supercapacitors (MSCs) with miniaturized volume and high-frequency response are regarded as a critical component in filtering circuits for microscale power conversion. Here, we reported the fabrication of the wafer-sized planar MSCs (M-MSCs) based on 2D Ti_(2)C_(2)T_(6) MXene using a photolithography technique. The M-MSCs exhibited an areal capacitance of 153 μF cm^(-2) and a frequency characteristic (f_(0)) of 5.6 k Hz in aqueous electrolyte. Moreover, by employing suitable ionic liquid as electrolyte, the voltage window was expanded to 2 V and the f_(0) could be pushed to 6.6 k Hz relying on the electrical double-layer mechanism and lower adsorption energy while maintaining quasi-rectangular cyclic voltammogram curves at 5000 V s^(-1). Furthermore, the integrated MSCs pack was constructed and exhibited excellent rectifying ability by filtering various highfrequency 5000 Hz AC signals with different waveforms into stable DC outputs. Such ultrahigh-rate and high-voltage M-MSCs module for k Hz AC line-filtering would be potentially integrated with customizable electronics to realize on-chip rectifiers in high-density integrated circuit.展开更多
Inorganic CsPbI_(2) Br perovskite solar cells(PSCs) have a tremendous development in last few years due to the trade-off between the excellent optoelectronic properties and the relatively outstanding stability.Herein,...Inorganic CsPbI_(2) Br perovskite solar cells(PSCs) have a tremendous development in last few years due to the trade-off between the excellent optoelectronic properties and the relatively outstanding stability.Herein,we demonstrated a strategy of secondary crystallization(SC) for CsPbI_(2) Br film in a facile planar n-i-p structure(ITO/ZnO-SnO_(2)/CsPbI_(2) Br/Spiro-OMeTAD/Ag) at low-temperature(150℃).It is achieved through the method of post-treatment with guanidinium bromine(GABr) atop annealed CsPbI_(2) Br film.It was found that the secondary crystallization by GABr can not only regulate the crystal growth and passivate defects,but also serve as a charge collection center to effectively collect photogenerated carriers.In addition,due to the excess Br ions in GABr,the formation of the Br-rich region at the CsPbI_(2) Br perovskite surface can further lower the Fermi level,leading to more beneficial band alignment between the perovskite and the hole transport layer(HTL),while the phase stability was also improved.As a result,the champion cell shows a superb open-circuit voltage(V_(oc)) of 1.31 V,a satisfactory power conversion efficiency(PCE) of 16.97% and outstanding stabilities.As far as we know,this should be one of the highest PCEs reported among all-inorganic CsPbI_(2) Br based PSCs.展开更多
Powered by electricity from renewable energies,electrochemical reduction of CO_(2)could not only efficiently alleviate the excess emission of CO_(2),but also produce many kinds of valuable chemical feedstocks.Among va...Powered by electricity from renewable energies,electrochemical reduction of CO_(2)could not only efficiently alleviate the excess emission of CO_(2),but also produce many kinds of valuable chemical feedstocks.Among various catalysts,single atom catalysts(SACs)have attracted much attention due to their high atom utilization efficiency and expressive catalytic performances.Additionally,SACs serve as an ideal platform for the investigation of complex reaction pathways and mechanisms thanks to their explicit active sites.In this review,the possible re-action pathways for the generation of various products(mainly C1 products for SACs)were firstly summarized.Then,recent progress of SACs for electrochemical reduction of CO_(2)was discussed in aspect of different central metal sites.As the most popular and efficient coordination modulation strategy,introducing heteroatom was then reviewed.Moreover,as an extension of SACs,the development of dual atom catalysts was also briefly discussed.At last,some issues and challenges regarding the SACs for CO_(2)reduction reaction(CO_(2)RR)were listed,followed by corresponding suggestions.展开更多
A preliminary study by our research group showed that 6-mm-long regeneration chamber bridging is equivalent to autologous nerve transplantation for the repair of 12-mm nerve defects. In this study, we compared the eff...A preliminary study by our research group showed that 6-mm-long regeneration chamber bridging is equivalent to autologous nerve transplantation for the repair of 12-mm nerve defects. In this study, we compared the efficacy of different lengths (6, 8, 10 mm) of nerve fragments bridging 6-mm regeneration chambers for the repair of 12-mm-long nerve defects. At 16 weeks after the regeneration chamber was implanted, the number, diameter and myelin sheath thickness of the regenerated nerve fibers, as well as the conduction velocity of the sciatic nerve and gastrocnemius muscle wet weight ratio, were similar to that observed with autologous nerve transplantation. Our results demonstrate that 6-, 8-and 10-mm-long nerve fragments bridging 6-mm regeneration chambers effectively repair 12-mm-long nerve defects. Because the chemoattractive capacity is not affected by the length of the nerve fragment, we suggest adopting 6-mm-long nerve fragments for the repair of peripheral nerve defects.展开更多
Due to excellent thermal stability and optoelectronic properties, all-inorganic perovskite is one of the promising candidates to solve the thermal decomposition problem of conventional organic–inorganic hybrid perovs...Due to excellent thermal stability and optoelectronic properties, all-inorganic perovskite is one of the promising candidates to solve the thermal decomposition problem of conventional organic–inorganic hybrid perovskite solar cells(PSCs),but the larger voltage loss(V_(loss)) cannot be ignored, especially CsPbIBr_(2), which limits the improvement of efficiency. To reduce V_(loss), one promising solution is the modification of the energy level alignment between the perovskite layer and adjacent charge transport layer(CTL), which can facilitate charge extraction and reduce carrier recombination rate at the perovskite/CTL interface. Therefore, the key issues of minimum V_(loss) and high efficiency of CsPbIBr_(2)-based PSCs were studied in terms of the perovskite layer thickness, the effects of band offset of the CTL/perovskite layer, the doping concentration of the CTL, and the electrode work function in this study based on device simulations. The open-circuit voltage(V_(oc)) is increased from 1.37 V to 1.52 V by replacing SnO_(2) with ZnO as the electron transport layer(ETL) due to more matching conduction band with the CsPbIBr;layer.展开更多
Recent developments in the synthesis of graphene-based structures focus on continuous improvement of porous nanostructures,doping of thin films,and mechanisms for the construction of threedimensional architectures.Her...Recent developments in the synthesis of graphene-based structures focus on continuous improvement of porous nanostructures,doping of thin films,and mechanisms for the construction of threedimensional architectures.Herein,we synthesize creeper-like Ni3Si2/NiOOH/graphene nanostructures via low-pressure all-solid meltingreconstruction chemical vapor deposition.In a carbon-rich atmosphere,high-energy atoms bombard the Ni and Si surface,and reduce the free energy in the thermodynamic equilibrium of solid Ni–Si particles,considerably catalyzing the growth of Ni–Si nanocrystals.By controlling the carbon source content,a Ni3Si2 single crystal with high crystallinity and good homogeneity is stably synthesized.Electrochemical measurements indicate that the nanostructures exhibit an ultrahigh specific capacity of 835.3 C g^−1(1193.28 F g^−1)at 1 A g^−1;when integrated as an all-solidstate supercapacitor,it provides a remarkable energy density as high as 25.9 Wh kg^−1 at 750 W kg^−1,which can be attributed to the freestanding Ni3Si2/graphene skeleton providing a large specific area and NiOOH inhibits insulation on the electrode surface in an alkaline solution,thereby accelerating the electron exchange rate.The growth of the high-performance composite nanostructure is simple and controllable,enabling the large-scale production and application of microenergy storage devices.展开更多
CsPbI_(2)Br perovskite solar cells have achieved rapid development owing to their exceptional optoelectronic properties and relatively outstanding stability.However,open-circuit voltage(Voc)loss caused by band mismatc...CsPbI_(2)Br perovskite solar cells have achieved rapid development owing to their exceptional optoelectronic properties and relatively outstanding stability.However,open-circuit voltage(Voc)loss caused by band mismatch and charge recombination between perovskite and charge transporting layer is one of the crucial obstacles to further improve the device performance.Here,we proposed a bilayer electron transport layer ZnO(bottom)/SnO_(2)(top)to reduce the Voc loss(Eloss)and promote device Voc by ZnO insert layer thickness modulation,which could improve the efficiency of charge carrier extraction/transfer and suppress the charge carrier recombination.In addition,guanidinium iodide top surface treatment is used to further reduce the trap density,stabilize the perovskite film and align the energy levels,which promotes the fill factor,short-circuit current density(Jsc),and stability of the device.As a result,the champion cell of double-side optimized CsPbI_(2)Br perovskite solar cells exhibits an extraordinary efficiency of 16.25%with the best Voc as high as 1.27 V and excellent thermal and storage stability.展开更多
The clinical efficacy of current cancer therapies falls short,and there is a pressing demand to integrate new targets with conventional therapies.Autophagy,a highly conserved self-degradation process,has received cons...The clinical efficacy of current cancer therapies falls short,and there is a pressing demand to integrate new targets with conventional therapies.Autophagy,a highly conserved self-degradation process,has received considerable attention as an emerging therapeutic target for cancer.With the rapid development of nanomedicine,nanomaterials have been widely utilized in cancer therapy due to their unrivaled delivery performance.Hence,considering the potential benefits of integrating autophagy and nanotechnology in cancer therapy,we outline the latest advances in autophagy-based nanotherapeutics.Based on a brief background related to autophagy and nanotherapeutics and their impact on tumor progression,the feasibility of autophagy-based nanotherapeutics for cancer treatment is demonstrated.Further,emerging nanotherapeutics developed to modulate autophagy are reviewed from the perspective of cell signaling pathways,including modulation of the mammalian target of rapamycin(mTOR)pathway,autophagy-related(ATG)and its complex expression,reactive oxygen species(ROS)and mitophagy,interference with autophagosome-lysosome fusion,and inhibition of hypoxia-mediated autophagy.In addition,combination therapies in which nano-autophagy modulation is combined with chemotherapy,phototherapy,and immunotherapy are also described.Finally,the prospects and challenges of autophagy-based nanotherapeutics for efficient cancer treatment are envisioned.展开更多
Solar-blind ultraviolet(UV)photodetectors based on p-organic/n-Ga_(2)O_(3) hybrid heterojunctions have attracted extensive attention recently.Herein,the multifunctional solar-blind photodetector based on p-type poly[N...Solar-blind ultraviolet(UV)photodetectors based on p-organic/n-Ga_(2)O_(3) hybrid heterojunctions have attracted extensive attention recently.Herein,the multifunctional solar-blind photodetector based on p-type poly[N-90-heptadecanyl-2,7-carbazole-alt-5,5-(40,70-di-2-thienyl-20,10,30-benzothiadiazole)](PCDTBT)/n-type amorphous Ga_(2)O_(3)(a-Ga_(2)O_(3))is fabricated and investigated,which can work in the phototransistor mode coupling with self-powered mode.With the introduction of PCDTBT,the dark current of such the a-Ga_(2)O_(3)-based photodetector is decreased to 0.48 pA.Meanwhile,the photoresponse parameters of the a-Ga_(2)O_(3)-based photodetector in the phototransistor mode to solar-blind UV light are further increased,that is,responsivity(R),photo-detectivity(D*),and external quantum efficiency(EQE)enhanced to 187 A W^(-1),1.3×10^(16) Jones and 9.1×10^(4)% under the weak light intensity of 11μW cm^(-2),respectively.Thanks to the formation of the built-in field in the p-PCDTBT/n-Ga_(2)O_(3) type-Ⅱ heterojunction,the PCDTBT/Ga_(2)O_(3) multifunctional photodetector shows self-powered behavior.The responsivity of p-PCDTBT/n-Ga_(2)O_(3) multifunctional photodetector is 57.5 mA W^(-1) at zero bias.Such multifunctional p-n hybrid heterojunction-based photodetectors set the stage for realizing high-performance amorphous Ga_(2)O_(3) heterojunction-based photodetectors.展开更多
Background:Plasminogen activator inhibitor-1(PAI-1)plays an important role in the pathophysiology of sepsis,but the exact mechanism remains debatable.In this study,we investigated the associations among the serum leve...Background:Plasminogen activator inhibitor-1(PAI-1)plays an important role in the pathophysiology of sepsis,but the exact mechanism remains debatable.In this study,we investigated the associations among the serum levels of PAI-1,the incidence of 4G/5G promoter PAI-1 gene polymorphisms,immunological indicators,and clinical outcomes in septic patients.Methods:A total of 181 patients aged 18-80 years with sepsis between November 2016 and August 2018 in the intensive care unit in the Xinhua Hospital were recruited in this retrospective study,with 28-day mortality as the primary outcome.The initial serum level of PAI-1 and the presence of rs1799768 single nucleotide polymorphisms(SNPs)were examined.Univariate logistic regression and multivariate analyses were performed to determine the factors associated with different genotypes of PAI-1,serum level of PAI-1,and 28-day mortality.Results:The logistic analysis suggested that a high serum level of PAI-1 was associated with the rs1799768 SNP of PAI-1(4G/4G and 4G/5G)(Odds ratio[OR]:2.49;95%confidence interval[CI]:1.09,5.68).Furthermore,a high serum level of PAI-1 strongly influenced 28-day mortality(OR 3.36;95%CI 1.51,7.49).The expression and activation of neutrophils(OR 0.96;95%CI 0.93,0.99),as well as the changes in the expression patterns of cytokines and chemokine-associated neutrophils(OR:1.00;95%CI:1.00,1.00),were both regulated by the genotype of PAI-1.Conclusions:Genetic polymorphisms of PAI-1 can influence the serum levels of PAI-1,which might contribute to mortality by affecting neutrophil activity.Thus,patients with severe sepsis might clinically benefit from enhanced neutrophil clearance and the resolution of inflammation via the regulation of PAI-1 expression and activity.展开更多
基金the National Natural Science Foundation of China(Grant No.62074120)the State Key Laboratory on Integrated Optoelectronics(Grant No.IOSKL2018KF10)the Fundamental Research Funds for the Central Universities(Grant No.JB211108).
文摘The nano-patterned InGaN film was used in green InGaN/GaN multiple quantum wells(MQWs)structure,to relieve the unpleasantly existing mismatch between high indium content InGaN and GaN,as well as to enhance the light output.The different self-assembled nano-masks were formed on InGaN by annealing thin Ni layers of different thicknesses.Whereafter,the InGaN films were etched into nano-patterned films.Compared with the green MQWs structure grown on untreated InGaN film,which on nano-patterned InGaN had better luminous performance.Among them the MQWs performed best when 3 nm thick Ni film was used as mask,because that optimally balanced the effects of nano-patterned InGaN on the crystal quality and the light output.
文摘Until very recently, gallium oxide(Ga_2O_3) has aroused more and more interests in the area of power electronics due to its ultra-wide bandgap of 4.5–4.8 eV, estimated critical field of 8 MV/cm and decent intrinsic electron mobility limit of250 cm2/(V·s), yielding a high Baliga's figures-of-merit(FOM) of more than 3000, which is several times higher than GaN and SiC.In addition to its excellent material properties, potential low-cost and large size substrate through melt-grown methodology also endows β-Ga_2O_3 more potential for future low-cost power devices. This article focuses on reviewing the most recent advances ofβ-Ga_2O_3 based power devices. It will be starting with a brief introduction to the material properties of β-Ga_2O_3 and then the growth techniques of its native substrate, followed by the thin film epitaxial growth. The performance of state-of-art β-Ga_2O_3 devices, including diodes and FETs are fully discussed and compared. Finally, potential solutions to the challenges of β-Ga_2O_3 are also discussed and explored.
基金financially supported by the National Natural Science Foundation of China(Nos.61604119,61704131,and 61804111)Initiative Postdocs Supporting Program(No.BX20180234)+2 种基金China Postdoctoral Science Foundation(No.2018M643578)Young Elite Scientists Sponsorship Program by CAST(2016QNRC001)Fundamental Research Funds for the Central Universities.
文摘Interface engineering has been regarded as an effective and noninvasive means to optimize the performance of perovskite solar cells(PSCs).Here,doping engineering of a ZnO electron transport layer(ETL)and CsPbI3/ZnO interface engineering via introduction of an interfacial layer are employed to improve the performances of CsPbI3-based PSCs.The results show that when introducing a TiO2 buffer layer while increasing the ZnO layer doping concentration,the open-circuit voltage,power conversion efficiency,and fill factor of the CsPbI3-based PSCs can be improved to 1.31 V,21.06%,and 74.07%,respectively,which are superior to those of PSCs only modified by the TiO2 buffer layer or high-concentration doping of ZnO layer.On the one hand,the buffer layer relieves the band bending and structural disorder of CsPbI3.On the other hand,the increased doping concentration of the ZnO layer improves the conductivity of the TiO2/ZnO bilayer ETL because of the strong interaction between the TiO2 and ZnO layers.However,such phenomena are not observed for those of a PCBM/ZnO bilayer ETL because of the weak interlayer interaction of the PCBM/ZnO interface.These results provide a comprehensive understanding of the CsPbI3/ZnO interface and suggest a guideline to design high-performance PSCs.
基金financial support from the National Natural Science Foundation of China(Nos.61804113,61874083)Initiative Postdocs Supporting Program(BX20190261)+1 种基金the National Natural Science Foundation of Shaanxi Province(2018ZDCXL-GY-08-02-02 and 2017JM6049)the Fundamental Research Funds for the Central Universities(JB181107 and JBX171103).
文摘A novel interface design is proposed for carbon-based,all-inorganic CsPbIBr2 perovskite solar cells(PSCs)by introducing interfacial voids between TiO2 electron transport layer and CsPbIBr2 absorber.Compared with the general interfacial engineering strategies,this design exempts any extra modification layer in final PSC.More importantly,the interfacial voids produced by thermal decomposition of 2-phenylethylammonium iodide trigger three beneficial e ects.First,they promote the light scattering in CsPbIBr2 film and thereby boost absorption ability of the resulting CsPbIBr2 PSCs.Second,they suppress recombination of charge carriers and thus reduce dark saturation current density(J0)of the PSCs.Third,interfacial voids enlarge built-in potential(Vbi)of the PSCs,awarding increased driving force for dissociating photo-generated charge carriers.Consequently,the PSC yields the optimized e ciency of 10.20%coupled with an open-circuit voltage(Voc)of 1.338 V.The Voc achieved herein represents the best value among CsPbIBr2 PSCs reported earlier.Meanwhile,the non-encapsulated PSCs exhibit an excellent stability against light,thermal,and humidity stresses,since it remains^97%or^94%of its initial e ciency after being heated at 85℃for 12 h or stored in ambient atmosphere with relative humidity of 30–40%for 60 days,respectively.
文摘Despite being the long-time mainstream semiconductor for both logic and power devices, Silicon is now facing its dilemma and limitation of scalability and material potential.Especially for power devices, people are demanding escalating efficiency with higher blocking voltage while its power consumption and heat generation are less. Constrained by its narrow bandgap of 1.14 eV, Silicon only has a critical breakdown field(E_c) of 0.3 MV/cm, yielding a Baliga figureof-merit(BFOM = ε×μ× E_c^3) of unity when normalized to itself. It is hence required that the dominating factor E_c should be as high as possible such that the BFOM will be hundreds or even thousands of times when compared to Silicon so as to minimize the conduction loss. Beta-Gallium Oxide(β-Ga_2O_3) with decent μ of 250 cm2/Vs, ultra-wide bandgap of4.8 eV and high critical E_c of 8 MV/cm, yielding a superior high BFOM of more than 3000. Therefore, system made withβ-Ga_2O_3 can be thinner, lighter and capable of handling more power than the one with Silicon. In addition, low-cost and large size substrate through melt-grown method endows β-Ga_2O_3 more potentials as cost-effective power devices. After resolving the low thermal conductivity issue,unipolar devices made with ultra-wide bandgap β-Ga_2O_3 are promised to make power transition and our life more efficient.
基金This study was supported by the funds from the Singapore Ministry of Education Academic Research Fund,Tier 1:RG111/15 and RG10/16 and Tier 2:MOE2016-T2-2 to 004.
文摘Electrochemical reduction of molecular O2 to hydrogen peroxide(H2O2)offers a promising solution for water purification and environmental remediation.Here,we design a hierarchical free-standing single-Co-atom(with Co-N4 coordination)electrode for oxygen reduction reaction(ORR)via a two-electron pathway to make H2O2 in acidic media.The current density of the single-Co-atom electrode reached 51 mA/cm2 at 0.1 V vs reversible hydrogen electrode,lasting for more than 10 hours of continuous operation with H2O2 selectivity greater than 80%.Toward practical application,the single-Co-atom electrode was directly used to assemble an electrochemical cell to produce H2O2 at a rate of 676 mol/kgcat/h with a cell voltage of about 1.6 V.
基金financially supported by the Natural Science Basic Research Plan in Shaanxi Province of China (2019ZDLGY1602)the Youth Science and Technology Nova Program of Shaanxi Province (2020KJXX-068)+8 种基金the Fundamental Research Funds for the Central Universities (JBF201101)the National Key R@D Program of China (2016YFA0200200)the National Natural Science Foundation of China (22125903, 51872283, 22075279, 21805273, 22109160)the Liao Ning Revitalization Talents Program (XLYC1807153)the Liaoning Bai Qian Wan Talents Program, Dalian Innovation Support Plan for High Level Talents (2019RT09)the Dalian National Laboratory For Clean Energy (DNL), CAS, DNL Cooperation Fund, CAS (DNL201912, DNL201915, DNL202016, DNL202019)DICP (DICP ZZBS201708, DICP ZZBS201802, DICP I2020032)the Joint Fund of the Yulin University and the Dalian National Laboratory for Clean Energy (YLU-DNL Fund 2021002, 2021009)the China Postdoctoral Science Foundation (2021M693126, 2021M693127, 2019M661141, 2020M680995)。
文摘Harnessing energy from the environment promotes the rapid development of micro-power generators and relevant power management modules of alternating current (AC) line-filtering to obtain a stabilized direct current (DC) output for storage and use. Micro-supercapacitors (MSCs) with miniaturized volume and high-frequency response are regarded as a critical component in filtering circuits for microscale power conversion. Here, we reported the fabrication of the wafer-sized planar MSCs (M-MSCs) based on 2D Ti_(2)C_(2)T_(6) MXene using a photolithography technique. The M-MSCs exhibited an areal capacitance of 153 μF cm^(-2) and a frequency characteristic (f_(0)) of 5.6 k Hz in aqueous electrolyte. Moreover, by employing suitable ionic liquid as electrolyte, the voltage window was expanded to 2 V and the f_(0) could be pushed to 6.6 k Hz relying on the electrical double-layer mechanism and lower adsorption energy while maintaining quasi-rectangular cyclic voltammogram curves at 5000 V s^(-1). Furthermore, the integrated MSCs pack was constructed and exhibited excellent rectifying ability by filtering various highfrequency 5000 Hz AC signals with different waveforms into stable DC outputs. Such ultrahigh-rate and high-voltage M-MSCs module for k Hz AC line-filtering would be potentially integrated with customizable electronics to realize on-chip rectifiers in high-density integrated circuit.
基金financially supported by the National Natural Science Foundation of China (61704131,61804111)the National Key Research and Development Program of China (Grant2018YFB2202900)+3 种基金the Key Research and Development Program of Shaanxi Province (Grant 2020GY-310)the Joint Research Funds of Department of Science & Technology of Shaanxi Province and Northwestern Polytechnical University (2020GXLH-Z-018)the Fundamental Research Funds for the Central Universitiesthe Innovation Fund of Xidian University。
文摘Inorganic CsPbI_(2) Br perovskite solar cells(PSCs) have a tremendous development in last few years due to the trade-off between the excellent optoelectronic properties and the relatively outstanding stability.Herein,we demonstrated a strategy of secondary crystallization(SC) for CsPbI_(2) Br film in a facile planar n-i-p structure(ITO/ZnO-SnO_(2)/CsPbI_(2) Br/Spiro-OMeTAD/Ag) at low-temperature(150℃).It is achieved through the method of post-treatment with guanidinium bromine(GABr) atop annealed CsPbI_(2) Br film.It was found that the secondary crystallization by GABr can not only regulate the crystal growth and passivate defects,but also serve as a charge collection center to effectively collect photogenerated carriers.In addition,due to the excess Br ions in GABr,the formation of the Br-rich region at the CsPbI_(2) Br perovskite surface can further lower the Fermi level,leading to more beneficial band alignment between the perovskite and the hole transport layer(HTL),while the phase stability was also improved.As a result,the champion cell shows a superb open-circuit voltage(V_(oc)) of 1.31 V,a satisfactory power conversion efficiency(PCE) of 16.97% and outstanding stabilities.As far as we know,this should be one of the highest PCEs reported among all-inorganic CsPbI_(2) Br based PSCs.
文摘Powered by electricity from renewable energies,electrochemical reduction of CO_(2)could not only efficiently alleviate the excess emission of CO_(2),but also produce many kinds of valuable chemical feedstocks.Among various catalysts,single atom catalysts(SACs)have attracted much attention due to their high atom utilization efficiency and expressive catalytic performances.Additionally,SACs serve as an ideal platform for the investigation of complex reaction pathways and mechanisms thanks to their explicit active sites.In this review,the possible re-action pathways for the generation of various products(mainly C1 products for SACs)were firstly summarized.Then,recent progress of SACs for electrochemical reduction of CO_(2)was discussed in aspect of different central metal sites.As the most popular and efficient coordination modulation strategy,introducing heteroatom was then reviewed.Moreover,as an extension of SACs,the development of dual atom catalysts was also briefly discussed.At last,some issues and challenges regarding the SACs for CO_(2)reduction reaction(CO_(2)RR)were listed,followed by corresponding suggestions.
基金supported by Key Scientific Research Projects of Liaoning Provincial Medical Peak Construction Engineering,No.2010074
文摘A preliminary study by our research group showed that 6-mm-long regeneration chamber bridging is equivalent to autologous nerve transplantation for the repair of 12-mm nerve defects. In this study, we compared the efficacy of different lengths (6, 8, 10 mm) of nerve fragments bridging 6-mm regeneration chambers for the repair of 12-mm-long nerve defects. At 16 weeks after the regeneration chamber was implanted, the number, diameter and myelin sheath thickness of the regenerated nerve fibers, as well as the conduction velocity of the sciatic nerve and gastrocnemius muscle wet weight ratio, were similar to that observed with autologous nerve transplantation. Our results demonstrate that 6-, 8-and 10-mm-long nerve fragments bridging 6-mm regeneration chambers effectively repair 12-mm-long nerve defects. Because the chemoattractive capacity is not affected by the length of the nerve fragment, we suggest adopting 6-mm-long nerve fragments for the repair of peripheral nerve defects.
基金financially supported by the National Natural Science Foundation of China (Grant No. 52192610)the Key Research and Development Program of Shaanxi Province, China (Grant No. 2020GY-310)+2 种基金Youth Project of Natural Science Basic Research Program of Shaanxi Province, China (Grant No. 2021JQ-189)the Joint Research Funds of Department of Science & Technology of Shaanxi Province and Northwestern Polytechnical University (Grant No. 2020GXLH-Z-018)the Fundamental Research Funds for the Central Universities, China。
文摘Due to excellent thermal stability and optoelectronic properties, all-inorganic perovskite is one of the promising candidates to solve the thermal decomposition problem of conventional organic–inorganic hybrid perovskite solar cells(PSCs),but the larger voltage loss(V_(loss)) cannot be ignored, especially CsPbIBr_(2), which limits the improvement of efficiency. To reduce V_(loss), one promising solution is the modification of the energy level alignment between the perovskite layer and adjacent charge transport layer(CTL), which can facilitate charge extraction and reduce carrier recombination rate at the perovskite/CTL interface. Therefore, the key issues of minimum V_(loss) and high efficiency of CsPbIBr_(2)-based PSCs were studied in terms of the perovskite layer thickness, the effects of band offset of the CTL/perovskite layer, the doping concentration of the CTL, and the electrode work function in this study based on device simulations. The open-circuit voltage(V_(oc)) is increased from 1.37 V to 1.52 V by replacing SnO_(2) with ZnO as the electron transport layer(ETL) due to more matching conduction band with the CsPbIBr;layer.
基金the Natural Science Basic Research Plan in Shaanxi Province of China(Program Nos.2019ZDLGY16-02,2019ZDLGY16-03,and 2019ZDLGY16-08)Youth Science and Technology Nova Program of Shaanxi Province(2020KJXX-068)the Wuhu and Xidian University special fund for industry-university-research cooperation(Program No.HX01201909039).
文摘Recent developments in the synthesis of graphene-based structures focus on continuous improvement of porous nanostructures,doping of thin films,and mechanisms for the construction of threedimensional architectures.Herein,we synthesize creeper-like Ni3Si2/NiOOH/graphene nanostructures via low-pressure all-solid meltingreconstruction chemical vapor deposition.In a carbon-rich atmosphere,high-energy atoms bombard the Ni and Si surface,and reduce the free energy in the thermodynamic equilibrium of solid Ni–Si particles,considerably catalyzing the growth of Ni–Si nanocrystals.By controlling the carbon source content,a Ni3Si2 single crystal with high crystallinity and good homogeneity is stably synthesized.Electrochemical measurements indicate that the nanostructures exhibit an ultrahigh specific capacity of 835.3 C g^−1(1193.28 F g^−1)at 1 A g^−1;when integrated as an all-solidstate supercapacitor,it provides a remarkable energy density as high as 25.9 Wh kg^−1 at 750 W kg^−1,which can be attributed to the freestanding Ni3Si2/graphene skeleton providing a large specific area and NiOOH inhibits insulation on the electrode surface in an alkaline solution,thereby accelerating the electron exchange rate.The growth of the high-performance composite nanostructure is simple and controllable,enabling the large-scale production and application of microenergy storage devices.
基金supported by National Natural Science Foundation of China(61704131 and 61804111)National Key Research and Development Program of China(Grant 2018YFB2202900)+2 种基金Key Research and Development Program of Shaanxi Province(Grant 2020GY-310)the Joint Research Funds of Department of Science&Technology of Shaanxi Province and Northwestern Polytechnical University(2020GXLH-Z-018)the Fundamental Research Funds for the Central Universities and the Innovation Fund of Xidian University.
文摘CsPbI_(2)Br perovskite solar cells have achieved rapid development owing to their exceptional optoelectronic properties and relatively outstanding stability.However,open-circuit voltage(Voc)loss caused by band mismatch and charge recombination between perovskite and charge transporting layer is one of the crucial obstacles to further improve the device performance.Here,we proposed a bilayer electron transport layer ZnO(bottom)/SnO_(2)(top)to reduce the Voc loss(Eloss)and promote device Voc by ZnO insert layer thickness modulation,which could improve the efficiency of charge carrier extraction/transfer and suppress the charge carrier recombination.In addition,guanidinium iodide top surface treatment is used to further reduce the trap density,stabilize the perovskite film and align the energy levels,which promotes the fill factor,short-circuit current density(Jsc),and stability of the device.As a result,the champion cell of double-side optimized CsPbI_(2)Br perovskite solar cells exhibits an extraordinary efficiency of 16.25%with the best Voc as high as 1.27 V and excellent thermal and storage stability.
基金the National Natural Science Foundation of China(No.81971729)for financial support.
文摘The clinical efficacy of current cancer therapies falls short,and there is a pressing demand to integrate new targets with conventional therapies.Autophagy,a highly conserved self-degradation process,has received considerable attention as an emerging therapeutic target for cancer.With the rapid development of nanomedicine,nanomaterials have been widely utilized in cancer therapy due to their unrivaled delivery performance.Hence,considering the potential benefits of integrating autophagy and nanotechnology in cancer therapy,we outline the latest advances in autophagy-based nanotherapeutics.Based on a brief background related to autophagy and nanotherapeutics and their impact on tumor progression,the feasibility of autophagy-based nanotherapeutics for cancer treatment is demonstrated.Further,emerging nanotherapeutics developed to modulate autophagy are reviewed from the perspective of cell signaling pathways,including modulation of the mammalian target of rapamycin(mTOR)pathway,autophagy-related(ATG)and its complex expression,reactive oxygen species(ROS)and mitophagy,interference with autophagosome-lysosome fusion,and inhibition of hypoxia-mediated autophagy.In addition,combination therapies in which nano-autophagy modulation is combined with chemotherapy,phototherapy,and immunotherapy are also described.Finally,the prospects and challenges of autophagy-based nanotherapeutics for efficient cancer treatment are envisioned.
基金supported by the National Key R&D Program of China(2022YFB3605402 and 2021YFB3601800)the Fundamental Research Funds for the Central Universities+3 种基金the National Natural Science Foundation of China(62274132,62004151,62274126,and 62174123)the Natural Science Basic Research Program of Shaanxi(2021JC24)the Innovation Capability Support Program of Shaanxi(2021TD-04)Wuhu and Xidian University Special Fund for Industry-university-research Cooperation(XWYCXY-012021001 and XWYCXY-012021006)。
基金National Key Research and Development Program of China,Grant/Award Numbers:2021YFA0715600,2021YFA0717700National Natural Science Foundation of China,Grant/Award Numbers:52192610,62274127,62304163,62374128+5 种基金State Key Laboratory of Infrared Physics,Grant/Award Number:SITP-NLIST-ZD-2023-03Songshan Lake Materials Laboratory,Grant/Award Number:2023SLABFN02Wuhu and Xidian University special fund for industry-university-research cooperation,Grant/Award Number:XWYCXY-012021004China Postdoctoral Science Foundation,Grant/Award Number:2023TQ0255Fundamental Research Funds for the Central UniversitiesInnovation Fund of Xidian University。
文摘Solar-blind ultraviolet(UV)photodetectors based on p-organic/n-Ga_(2)O_(3) hybrid heterojunctions have attracted extensive attention recently.Herein,the multifunctional solar-blind photodetector based on p-type poly[N-90-heptadecanyl-2,7-carbazole-alt-5,5-(40,70-di-2-thienyl-20,10,30-benzothiadiazole)](PCDTBT)/n-type amorphous Ga_(2)O_(3)(a-Ga_(2)O_(3))is fabricated and investigated,which can work in the phototransistor mode coupling with self-powered mode.With the introduction of PCDTBT,the dark current of such the a-Ga_(2)O_(3)-based photodetector is decreased to 0.48 pA.Meanwhile,the photoresponse parameters of the a-Ga_(2)O_(3)-based photodetector in the phototransistor mode to solar-blind UV light are further increased,that is,responsivity(R),photo-detectivity(D*),and external quantum efficiency(EQE)enhanced to 187 A W^(-1),1.3×10^(16) Jones and 9.1×10^(4)% under the weak light intensity of 11μW cm^(-2),respectively.Thanks to the formation of the built-in field in the p-PCDTBT/n-Ga_(2)O_(3) type-Ⅱ heterojunction,the PCDTBT/Ga_(2)O_(3) multifunctional photodetector shows self-powered behavior.The responsivity of p-PCDTBT/n-Ga_(2)O_(3) multifunctional photodetector is 57.5 mA W^(-1) at zero bias.Such multifunctional p-n hybrid heterojunction-based photodetectors set the stage for realizing high-performance amorphous Ga_(2)O_(3) heterojunction-based photodetectors.
基金supported by grants from the National Natural Science Foundation of China(Nos.82172138 and 81873947)Special Medical Innovation Project of Shanghai Science and Technology Committee(No.21Y11902400)the Key Laboratory of Emergency and Trauma(Hainan Medical University),Ministry of Education(No.KLET-202016)
文摘Background:Plasminogen activator inhibitor-1(PAI-1)plays an important role in the pathophysiology of sepsis,but the exact mechanism remains debatable.In this study,we investigated the associations among the serum levels of PAI-1,the incidence of 4G/5G promoter PAI-1 gene polymorphisms,immunological indicators,and clinical outcomes in septic patients.Methods:A total of 181 patients aged 18-80 years with sepsis between November 2016 and August 2018 in the intensive care unit in the Xinhua Hospital were recruited in this retrospective study,with 28-day mortality as the primary outcome.The initial serum level of PAI-1 and the presence of rs1799768 single nucleotide polymorphisms(SNPs)were examined.Univariate logistic regression and multivariate analyses were performed to determine the factors associated with different genotypes of PAI-1,serum level of PAI-1,and 28-day mortality.Results:The logistic analysis suggested that a high serum level of PAI-1 was associated with the rs1799768 SNP of PAI-1(4G/4G and 4G/5G)(Odds ratio[OR]:2.49;95%confidence interval[CI]:1.09,5.68).Furthermore,a high serum level of PAI-1 strongly influenced 28-day mortality(OR 3.36;95%CI 1.51,7.49).The expression and activation of neutrophils(OR 0.96;95%CI 0.93,0.99),as well as the changes in the expression patterns of cytokines and chemokine-associated neutrophils(OR:1.00;95%CI:1.00,1.00),were both regulated by the genotype of PAI-1.Conclusions:Genetic polymorphisms of PAI-1 can influence the serum levels of PAI-1,which might contribute to mortality by affecting neutrophil activity.Thus,patients with severe sepsis might clinically benefit from enhanced neutrophil clearance and the resolution of inflammation via the regulation of PAI-1 expression and activity.