Optimize Purcell filter design for reducing influence of fabrication variation

To protect superconducting qubits and enable rapid readout, optimally designed Purcell filters are essential. To suppress the off-resonant driving of untargeted readout resonators, individual Purcell filters are used for each readout resonator.However, achieving consistent frequency between a readout resonator and a Purcell filter is a significant challenge. A systematic computational analysis is conducted to investigate how fabrication variation affects filter performance, through focusing on the coupling capacitor structure and coplanar waveguide(CPW) transmission line specifications. The results indicate that the T-type enclosing capacitor(EC), which exhibits lower structural sensitivity, is more advantageous for achieving target capacitance than the C-type EC and the interdigital capacitor(IDC). By utilizing a large-sized CPW with the T-type EC structure, fluctuations in the effective coupling strength can be reduced to 10%, given typical micro-nanofabrication variances. The numerical simulations presented in this work minimize the influence of fabrication deviations, thereby significantly improving the reliability of Purcell filter designs.

Facile integration of an Al-rich Al_(1-x)In_(x)N photodetector on free-standing GaN by radio-frequency magnetron sputtering

Al_(1-x)In_(x)N, a Ⅲ-nitride semiconductor material, is currently of great research interest due to its remarkable physical properties and chemical stability. When the Al and In compositions are tuned, its band-gap energy varies from 0.7 eV to 6.2 eV, which shows great potential for application in photodetectors. Here, we report the fabrication and performance evaluation of integrated Al_(1-x)In_(x)N on a free-standing GaN substrate through direct radio-frequency magnetron sputtering.The optical properties of Al_(1-x)In_(x)N will be enhanced by the polarization effect of a heterostructure composed of Al_(1-x)In_(x)N and other Ⅲ-nitride materials. An Al_(1-x)In_(x)N/Ga N visible-light photodetector was prepared by semiconductor fabrication technologies such as lithography and metal deposition. The highest photoresponsivity achieved was 1.52 A·W^(-1)under 365 nm wavelength illumination and the photodetector was determined to have the composition Al0.75In0.25N/GaN.A rise time of 0.55 s was observed after transient analysis of the device. The prepared Al_(1-x)In_(x)N visible-light photodetector had a low dark current, high photoresponsivity and fast response speed. By promoting a low-cost, simple fabrication method,this study expands the application of ternary alloy Al_(1-x)In_(x)N visible-light photodetectors in optical communication.

A model cathode for mechanistic study of organosulfide electrochemistry in Li-organosulfide batteries

Organosulfides offer new opportunities for high performance lithium-sulfur(Li-S)batteries because of materials abundance,versatile structures and unique properties.Yet,their redox kinetics as well as cycling performance need to be further improved.Employing redox mediators is a highly effective strategy to address above challenges.However,the underlying mechanism in this chemistry is so far insufficiently explored.Here,phenyl disulfide(Ph S–SPh)and phenyl diselenide(Ph Se–Se Ph)are used as a model system for mechanistic understanding of organosulfide electrochemistry,particularly the rate acceleration.Profiling the reaction thermodynamics and charge-discharge process reveals redox of both S–S and C–S bonds,as well as that the coupling between radical exchange and electrochemical redox is the key to enhance the sulfur kinetics.This study not only establishes a basic understanding of orgaonsulfide electrochemistry in Li-S batteries,but also points out a general strategy for enhancing the kinetics of sulfur electrodes in electrochemical devices.

Dual-Functional Organotelluride Additive for Highly Efficient Sulfur Redox Kinetics and Lithium Regulation in Lithium–Sulfur Batteries

High energy density and low cost made lithium–sulfur(Li–S)batteries appealing for the next-generation energy storage devices.However,their commercial viability is seriously challenged by serious polysulfide shuttle effect,sluggish sulfur kinetics,and uncontrollable dendritic Li growth.Herein,a dual-functional electrolyte additive,diphenyl ditelluride(DPDTe)is reported for Li–S battery.For sulfur cathodes,DPDTe works as a redox mediator to accelerate redox kinetics of sulfur,in which Te radical-mediated catalytic cycle at the solid–liquid interface contributes significantly to the whole process.For lithium anodes,DPDTe can react with lithium metal to form a smooth and stable organic–inorganic hybrid solid-electrolyte interphase(SEI),enabling homogeneous lithium deposition for suppressing dendrite growth.Consequently,the Li–S battery with DPDTe exhibits remarkable cycling stability and superb rate capability,with a high capacity up to 1227.3 mAh g^(-1)and stable cycling over 300 cycles.Moreover,a Li–S pouch cell with DPDTe is evaluated as the proof of concept.This work demonstrates that organotelluride compounds can be used as functional electrolyte additives and offers new insights and opportunities for practical Li–S batteries.

Construction of a High-Quality Organic-Inorganic Hybrid Heterostructure and Its Photo-response Performance

The combination of metal oxide and organic semiconductor for constructing organic-inorganic hybrid heterostructure is promising to offer unique optoelectronic properties.However,the distinct difference in electron structure and processing technology of the two types of materials makes it usually difficult to fully deliver their complementary advantages.Herein,we report the construction of a high quality organic/In_(2)O_(3) hybrid heterostructure presenting a good ambipolar transport with average electron mobility>1 cm^(2)V^(-1)·s^(-1) and hole mobility up to 0.4 cm^(2)·V^(-1)·s^(-1),respectively,together with a high-gain inverter.In addition,the incorporation with organic film on top of In_(2)O_(3) remarkably reduces the dark current,enabling the realization of high photoconductivity response with photo-sensitivity of two magnitudes higher than that of pure In2O3.The photoconductor and phototransistor of the hybrid structure demonstrate high photoresponsivity>10^(3) AW^(-1) and detectivity up to 10^(14) Jones,demonstrating the promising functionality of such a high quality hybrid heterostructure.

“In-N-out” design enabling high-content triethyl phosphate-based non-flammable and high-conductivity electrolytes for lithium-ion batteries

Safety issues related to flammable electrolytes in lithium-ion batteries(LIBs) remain a major challenge for their extended applications.The use of non-flammable phosphate-based electrolytes has proved the validity in inhibiting the combustion of LIBs.However,the strong interaction between Li^(+) and phosphate leads to a dominant solid electrolyte interphase(SEI) with limited electronic shielding,resulting in the poor Li^(+) intercalation at the graphite(Gr) anode when using high-phosphate-content electrolytes.To mitigate this issue and improve Li^(+) insertion,we propose an “In-N-Out” strategy to render phosphates “noncoordinative”.By employing a combination of strongly polar solvents for a “block effect” and weakly polar solvents for a “drag effect”,we reduce the Li^(+)–phosphate interaction.As a result,phosphates remain in the electrolyte phase(“In”),minimizing their impact on the incompatibility with the Gr electrode(“Out”).We have developed a non-flammable electrolyte with high triethyl phosphate(TEP) content(>60 wt.%),demonstrating the excellent ion conductivity(5.94 mS cm^(-1) at 30 ℃) and reversible Li^(+) intercalation at a standard concentration(~1 mol L^(-1)).This approach enables the manipulation of multiple electrolyte functions and holds the promise for the development of safe electrochemical energy storage systems using non-flammable electrolytes.

从废旧电池中直接提取锂实现锂的高效回收

The flourishing expansion of the lithium-ion batteries(LIBs) market has led to a surge in the demand for lithium resources. Developing efficient recycling technologies for imminent large-scale retired LIBs can significantly facilitate the sustainable utilization of lithium resources. Here, we successfully extract active lithium from spent LIBs through a simple, efficient, and low-energy-consumption chemical leaching process at room temperature, using a solution comprised of polycyclic aromatic hydrocarbons and ether solvents. The mechanism of lithium extraction is elucidated by clarifying the relationship between the redox potential and extraction efficiency. More importantly, the reclaimed active lithium is directly employed to fabricate LiFePO_(4) cathode with performance comparable to commercial materials. When implemented in 56 Ah prismatic cells, the cells deliver stable cycling properties with a capacity retention of ~90% after 1200 cycles. Compared with the other strategies, this technical approach shows superior economic benefits and practical promise. It is anticipated that this method may redefine the recycling paradigm for retired LIBs and drive the sustainable development of industries.

Growth Behavior of Rubrene Thin Films on Hexagonal Boron Nitride in the Early Stage

Two-dimensional materials,with an in-plane ordered and dangling-bonding-free surface,are ideal substrates for fabricating high-quality crystalline thin films.Here,we show a systematic study on the growth of a benchmark organic semiconductor,rubrene,on hexagonal boron nitride(h-BN)substrate via physical vapor deposition from the initial amorphous phase to the final crystalline phase;the role of temperature in such transition and the epitaxy relationship between rubrene and h-BN are revealed.With the increase of substrate temperature,the critical thickness of amorphous-crystalline-transition decreases and the morphology of crystalline phase also evolves from porous to terrace-like.When substrate temperature reaches>100℃,the critical thickness reduces to only 0.5 nm and a precise layer-by-layer growth from the very first layer is achieved,which is quite rare for rubrene growing on other substrates.The high ordering can be attributed to the fine epitaxy relationship between rubrene films and the h-BN surface lattice,and this film demonstrates good charge transport ability with a p-type field-effect mobility of>1 cm^(2)·V^(-1)·s^(-1).

类液晶作为高性能有机场效应晶体管的有源层

高载流子迁移率和器件性能的一致性对于有机场效应晶体管在阵列和集成电路上的应用至关重要.然而,同时具备高性能和小批间差的方法当前仍然是个挑战.本论文在原子力显微镜和偏振荧光显微镜表征的基础上,报道了在PTCDI-C1_(3)分子模板上生长具有大晶畴的dif-TES-ADT类液晶状薄膜的方法.我们进一步将所获得的薄膜用作有机场效应晶体管的载流子传输通道,其饱和载流子迁移率高达1.62±0.26 cm^(2)V^(-1)s^(-1).更重要的是,在重复三个批次之间,每次50个器件的迁移率批间差仅为16%.这一发现为设计材料和器件结构以同时实现高载流子迁移率和器件均匀性提供了一种新思路.

悬浮于石墨烯空位/孔洞中的独立纳米结构

在电子束辐照下,石墨烯较易形成空位、孔洞等缺陷,从而捕获外来原子,形成新的结构.由于这些结构具有一些令人兴奋的性质,它们和石墨烯之间的相互作用引起了科研工作者相当大的研究兴趣.本文总结了利用透射电子显微镜在制备和表征悬浮在石墨烯中的独立纳米结构的方法,以及原子分辨率下观察到的此类材料中原子/结构的动态行为过程,讨论了新型金属/非金属掺杂剂对具有不同键结构的石墨烯空位的影响,以及位于石墨烯边缘的单原子/团簇的催化活性.此外,还讨论了独立单原子厚二维团簇/金属/金属烯和二维团簇/金属/金属烯氧化物的动态形成过程.并指出这些纳米结构的形成、稳定性和宏观效应对于新的原子/分子尺度纳米技术的实际应用至关重要.以上数据证实了新型纳米结构的数量不断增加,并预示着相关研究的不断深入.

Core processing neuron-enabled circuit motifs for neuromorphic computing

Based on brain-inspired computing frameworks,neuromorphic systems implement large-scale neural networks in hardware.Although rapid advances have been made in the development of artificial neurons and synapses in recent years,further research is beyond these individual components and focuses on neuronal circuit motifs with specialized excitatory-inhibitory(E-I)connectivity patterns.In this study,we demonstrate a core processor that can be used to construct commonly used neuronal circuits.The neuron,featuring an ultracompact physical configuration,integrates a volatile threshold switch with a gate-modulated two-dimensional(2D)MoS_(2) field-effect channel to process complex E-I spatiotemporal spiking signals.Consequently,basic neuronal circuits are constructed for biorealistic neuromorphic computing.For practical applications,an algorithm-hardware co-design is implemented in a gatecontrolled spiking neural network with substantial performance improvement in human speech separation.

Multifunctional biomimetic tactile system via a stick-slip sensing strategy for human–machine interactions

A tactile sensor system enables natural interaction between humans and machines;this interaction is crucial for dexterous robotic hands,interactive entertainment,and other smart scenarios.However,the lack of sliding friction detection significantly limits the accuracy and scope of interactions due to the absence of sophisticated information,such as slippage,material and roughness of held objects.Here,inspired by the stick-slip phenomena in the sliding process,we have developed a multifunctional biomimetic tactile system based on the stick-slip sensing strategy,which is a universal method to detect slippage and estimate the surface properties of objects by sliding.This system consists of a flexible fingertip-inspired tactile sensor,a read-out circuit and a machinelearning module.Based on the stick-slip sensing strategy,our system was endowed with high recognition rates for slippage detection(100.0%),material classification(93.3%)and roughness discrimination(92.8%).Moreover,robotic hand manipulation,interactive games and object classification are demonstrated with this multifunctional system for comprehensive and promising human-machine interactions.

An artificial neuromorphic somatosensory system with spatio-temporal tactile perception and feedback functions

The advancement in flexible electronics and neuromorphic electronics has opened up opportunities to construct artificial perception systems to emulate biological functions which are of great importance for intelligent robotics and human-machine interactions.However,artificial systems that can mimic the somatosensory feedback functions have not been demonstrated yet despite the great achievement in this area.In this work,inspired by human somatosensory feedback pathways,an artificial somatosensory system with both perception and feedback functions was designed and constructed by integrating the flexible tactile sensors,synaptic transistor,artificial muscle,and the coupling circuit.Also,benefiting from the synaptic characteristics of the designed artificial synapse,the system shows spatio-temporal information-processing ability,which can further enhance the efficiency of the system.This research outcome has a potential contribution to the development of sensor technology from signal sensing to perception and cognition,which can provide a special paradigm for the next generation of bionic tactile perception systems towards e-skin,neurorobotics,and advanced bio-robots.

Interface terminal group regulated organic phototransistors with tunable persistent and switchable photoconductivity

With both light detection and intrinsic amplification functions,organic phototransistors have demonstrated promising applications,including photodetection and photomemory.To achieve excellent photoresponse and superior photogain,a common and effective strategy is to modulate the trapping effect with the purpose of reducing recombination or prolonging the lifetime of the photogenerated charge carriers.However,introducing trapping sites delicately is challenging and might sacrifice the response rate together with a typical persistent photoconductivity.Here,we demonstrate a facile strategy for achieving high photo-responsive organic phototransistors with both persistent and switchable photoconductivity features via interface terminal group regulation.By varying the terminate groups of self-assembled monolayer(SAMs)from the strong electron withdrawing group-F,neutral−CH_(3) to electron donating−NH_(2) on the dielectric surface,we realize both minority carrier trapping and majority carrier trapping in the organic phototransistor based on the C8-BTBT active layer.The electron withdrawing effect of F significantly enhances the minority carrier trapping process and yields a high photoresponsivity with a long-lasting persistent photoconductivity.In contrast,the electron donating group−NH_(2) with a distinct majority carrier trapping ability causes switchable photoconductivity so that the photocurrent can rise pronouncedly and fully decay along with light on/off.Attractively,both cases can deliver high performance with photoresponsivities higher than 104 A W^(−1) together with a photosensitivity in the level of 107 and a detectivity of approximately 10^(15)–10^(16) Jones.Such a tunable,excellent photoresponse property enables the convenient exploration of organic phototransistors to satisfy different application requirements.

Heteronanostructural metal oxide-based gas microsensors

The development of high-performance,portable and miniaturized gas sensors has aroused increasing interest in the fields of environmental monitoring,security,medical diagnosis,and agriculture.Among different detection tools,metal oxide semiconductor(MOS)-based chemiresistive gas sensors are the most popular choice in commercial applications and have the advantages of high stability,low cost,and high sensitivity.One of the most important ways to further enhance the sensor performance is to construct MOS-based nanoscale heterojunctions(heteronanostructural MOSs)from MOS nanomaterials.However,the sensing mechanism of heteronanostructural MOS-based sensors is different from that of single MOS-based gas sensors in that it is fairly complex.The performance of the sensors is influenced by various parameters,including the physical and chemical properties of the sensing materials(e.g.,grain size,density of defects,and oxygen vacancies of materials),working temperatures,and device structures.This review introduces several concepts in the design of high-performance gas sensors by analyzing the sensing mechanism of heteronanostructural MOS-based sensors.In addition,the influence of the geometric device structure determined by the interconnection between the sensing materials and the working electrodes is discussed.To systematically investigate the sensing behavior of the sensor,the general sensing mechanism of three typical types of geometric device structures based on different heteronanostructural materials are introduced and discussed in this review.This review will provide guidelines for readers studying the sensing mechanism of gas sensors and designing high-performance gas sensors in the future.