Ion–Electron Coupling Enables Ionic Thermoelectric Material with New Operation Mode and High Energy Density

Ionic thermoelectrics(i-TE) possesses great potential in powering distributed electronics because it can generate thermopower up to tens of millivolts per Kelvin. However,as ions cannot enter external circuit, the utilization of i-TE is currently based on capacitive charge/discharge, which results in discontinuous working mode and low energy density. Here,we introduce an ion–electron thermoelectric synergistic(IETS)effect by utilizing an ion–electron conductor. Electrons/holes can drift under the electric field generated by thermodiffusion of ions, thus converting the ionic current into electrical current that can pass through the external circuit. Due to the IETS effect, i-TE is able to operate continuously for over 3000 min.Moreover, our i-TE exhibits a thermopower of 32.7 mV K^(-1) and an energy density of 553.9 J m^(-2), which is more than 6.9 times of the highest reported value. Consequently, direct powering of electronics is achieved with i-TE. This work provides a novel strategy for the design of high-performance i-TE materials.

Optimizing interfacial electronic coupling with metal oxide to activate inert polyaniline for superior electrocatalytic hydrogen generation

Tuning and optimization of electronic structures and related reaction energetics are critical toward the rational design of efficient electrocatalysts.Herein,experimental and theoretical calculation demonstrate the originally inert N site within polyaniline(PANI)can be activated for hydrogen evolution by proper d-πinterfacial electronic coupling with metal oxide.As a result,the assynthesized WO3 assemblies@PANI via a facile redox-induced assembly and in situ polymerization,exhibits the electrocatalytic production of hydrogen better than other control samples including W18O49@PANI and most of the reported nobel-metal-free electrocatalysts,with low overpotential of 74 mV at 10 mA·cm−2 and small Tafel slope of 46 mV·dec−1 in 0.5M H2SO4(comparable to commercial Pt/C).The general efficacy of this methodology is also validated by extension to other metal oxides such as MoO3 with similar improvements.

Special Issue on Electromechanical Coupling Design for Electronic Equipment

With the development of electronic equipment to high accuracy, high density, high frequency, and atrocious ser- vice environment, the functional surface in this type of equipment has increasingly serious problems,

Electronic Coupling of Single Atom and FePS_3 Boosts Water Electrolysis

Engineering the electronic structure of surface active sites at the atomic level can be an efficient way to modulate the reactivity of catalysts.Herein,we report the rational tuning of surface electronic structure of FePS_(3) nanosheets(NSs)by anchoring atomically dispersed metal atom.Theoretical calculations predict that the strong electronic coupling effect in single-atom Ni-FePS_(3) facilitates electron aggregation from Fe atom to the nearby Ni-S bond and enhances the electron-transfer of Ni and S sites,which balances the oxygen species adsorption capacity,reinforces water adsorption and dissociation process to accelerate corresponding oxygen evolution reaction(OER)and hydrogen evolution reaction(HER).The optimal Ni-FePS_(3)NSs/C exhibits outstanding electrochemical water-splitting activities,delivering an overpotential of 287 mV at the current density of 10 mA cm^(-2) and a Tafel slope of 41.1 mV dec^(-1) for OER;as well as an overpotential decrease of 219 mV for HER compared with pure FePS_(3)NSs/C.The concept of electronic coupling interaction between the substrate and implanted single active species offers an additional method for catalyst design and beyond.

Evidence for bosonic mode coupling in electron dynamics of LiFeAs superconductor

Super-high resolution laser-based angle-resolved photoemission measurements are carried out on LiFeAs superconductor to investigate its electron dynamics. Three energy scales at ~ 20 meV, ~ 34 meV, and ~ 55 meV are revealed for the first time in the electron self-energy both in the superconducting state and normal state. The ~ 20 meV and ~ 34 meV scales can be attributed to the coupling of electrons with sharp bosonic modes which are most likely phonons. These observations provide definitive evidence on the existence of mode coupling in iron-based superconductors.

Coupling Modeling for Functional Surface of Electronic Equipment

High performance electromechanical equipment is widely used in various fields, such as national defense, industry and so on [ 1]. In addition, the technical level of high performance electromechanical equipment is the embodiment of the national level of science and technology.

The rise of supercapacitor diodes:Current progresses and future challenges

Supercapacitor has been widely known as a representative electrochemical energy storage device with high power density and long lifespan.Recently,with the deeper understanding of its charge storage mechanism,unidirectional-charging supercapacitor,also called supercapacitor diode(CAPode),is successfully developed based on the ion-sieving effect of its working electrode towards electrolyte ions.Because CAPode integrates mobile ion and mobile electron in one hybrid circuit,it has a great potential in the emerging fields of ion/electron coupling logic operations,human–machine interface,neural network interaction,and in vivo diagnosis and treatment.Accordingly,we herein elucidate the working mechanism and design philosophy of CAPode,and summarize the electrode materials that are suitable for constructing CAPode.Meanwhile,some other supercapacitor-based devices beyond CAPode are also introduced,and their potential applications are instructively presented.Finally,we outline the challenges and chances of CAPode-related techniques.

Superconducting state in Ba_((1-x)) Sr_(x)Ni_(2)As_(2) near the quantum critical point

In the phase diagram of the nickel-based superconductor Ba_(1-x)Sr_(x)Ni_(2)As_(2),T_(C) has been found to be enhanced sixfold near the quantum critical point(QCP) x=0.71 compared with the parent compound.However,the mechanism is still under debate.Here,we report a detailed investigation of the superconducting properties near the QCP(x≈0.7) by utilizing scanning tunneling microscopy and spectroscopy.The temperature-dependent superconducting gap and magnetic vortex state were obtained and analyzed in the framework of the Bardeen-Cooper-Schrieffer model.The ideal isotropic s-wave superconducting gap excludes the long-speculated nematic fluctuations while preferring strong electron-phonon coupling as the mechanism for T_(C) enhancement near the QCP.The lower than expected gap ratio of Δ/(k_(B) T_(C)) is rooted in the fact that Ba_(1-x)Sr_(x)Ni_(2)As_(2) falls into the dirty limit with a serious pair breaking effect similar to the parent compound.

Effect of driving frequency on electron heating in capacitively coupled RF argon glow discharges at low pressure

A one-dimensional（1D） fluid model on capacitively coupled radio frequency（RF） argon glow discharge between parallel-plates electrodes at low pressure is established to test the effect of the driving frequency on electron heating. The model is solved numerically by a finite difference method. The numerical results show that the discharge process may be divided into three stages： the growing rapidly stage, the growing slowly stage, and the steady stage. In the steady stage,the maximal electron density increases as the driving frequency increases. The results show that the discharge region has three parts： the powered electrode sheath region, the bulk plasma region and the grounded electrode sheath region. In the growing rapidly stage（at 18 μs）, the results of the cycle-averaged electric field, electron temperature, electron density, and electric potentials for the driving frequencies of 3.39, 6.78, 13.56, and 27.12 MHz are compared, respectively. Furthermore,the results of cycle-averaged electron pressure cooling, electron ohmic heating, electron heating, and electron energy loss for the driving frequencies of 3.39, 6.78, 13.56, and 27.12 MHz are discussed, respectively. It is also found that the effect of the cycle-averaged electron pressure cooling on the electrons is to ＂cool＂ the electrons; the effect of the electron ohmic heating on the electrons is always to ＂heat＂ the electrons; the effect of the cycle-averaged electron ohmic heating on the electrons is stronger than the effect of the cycle-averaged electron pressure cooling on the electrons in the discharge region except in the regions near the electrodes. Therefore, the effect of the cycle-averaged electron heating on the electrons is to ＂heat＂ the electrons in the discharge region except in the regions near the electrodes. However, in the regions near the electrodes, the effect of the cycle-averaged electron heating on the electron is to ＂cool＂ the electrons. Finally, the space distributions of the electron pressure cooling the electron ohmic heating and the electron heating at 1/4 T, 2/4 T, 3/4 T, and 4/4 T in one RF-cycle are presented and compared.

Coupling metal oxide nanoparticle catalysts for water oxidation to molecular light absorbers

Water oxidation, as a mandatory reaction of solar fuels conversion systems, requires the use of light absorbers with electronic properties that are well matched with those of the multi-electron catalyst in order to achieve high efficiency. Molecular light absorbers offer flexibility in fine tuning of orbital energetics,and metal oxide nanoparticles have emerged as robust oxygen evolving catalysts. Hence, these material choices offer a promising approach for the development of photocatalytic systems for water oxidation.However, efficient charge transfer coupling of molecular light absorbers and metal oxide nanoparticle catalysts has proven a challenge. Recent new approaches toward the efficient coupling of these components based on synthetic design improvements combined with direct spectroscopic observation and kinetic evaluation of charge transfer processes are discussed.

Electron Spin Decoherence of Nitrogen-Vacancy Center Coupled to Multiple Spin Baths

We present the experimental results of nitrogen-vacancy （NV） electron spin decoherence, which are linked to the coexistence of electron spin bath of nitrogen impurity （PI center） and 13C nuclear spin bath. In previous works, only one dominant decoherence source is studied： P1 electron spin bath for type-Ⅰb diamond; or 13C nuclear spin bath for type-Ⅱa diamond. In general, the thermal fluctuation from both spin baths can be eliminated by the Hahn echo sequence, resulting in a long coherence time （T2 ） of about 400#8. However, in a high-purity type-Ⅱa diamond where 1℃ nuclear spin bath is the dominant decoherence source, dramatic decreases of NV electron spin T2 time caused by P1 electron spin bath are observed under certain magnetic field. We further apply the engineered Hahn echo sequence to confirm the decoherenee mechanism of multiple spin baths and quantitatively estimate the contribution of P1 electron spin bath. Our results are helpful to understand the NV decoherence mechanisms, which will benefit quantum computing and quantum metrology.

Controlling the Goos-H?nchen Shift via Incoherent Pumping Field and Electron Tunneling in the Triple Coupled InGaAs/GaAs Quantum Dots

We study the controlling of the Goos-Hanchen （GH） shifts in reflected and transmitted light beams in the triple coupled InGaAs/GaAs quantum dot （QD） nanostructures with electron tunneling and incoherent pumping field. It is shown that the lateral shift can become either large negative or large positive, which can be controlled by the electron tunneling and the rate of incoherent pump field in different incident angles. It is also demonstrated that the properties of the OH shifts are strongly dependent on the probe absorption beam of the intracavity medium due to the switching from superluminal light propagation to subluminal behavior or vice versa. Our suggested system can be considered as a new theoretical method for developing a new nano-optoelectronic sensor.

Effect of ballistic electrons on ultrafast thermomechanical responses of a thin metal film

The ultrafast thermomechanical coupling problem in a thin gold film irradiated by ultrashort laser pulses with different electron ballistic depths is investigated via the ultrafast thermoelasticity model. The solution of the problem is obtained by solving finite element governing equations. The comparison between the results of ultrafast thermomechanical coupling responses with different electron ballistic depths is made to show the ballistic electron effect. It is found that the ballistic electrons have a significant influence on the ultrafast thermomechanical coupling behaviors of the gold thin film and the best laser micromachining results can be achieved by choosing the specific laser technology（large or small ballistic range）.In addition, the influence of simplification of the ultrashort laser pulse source on the results is studied, and it is found that the simplification has a great influence on the thermomechanical responses, which implies that care should be taken when the simplified form of the laser source term is applied as the Gaussian heat source.

Photon-assisted electronic and spin transport through two T-shaped three-quantum-dot molecules embedded in an Aharonov-Bohm interferometer

We investigate the time-modulated electronic and spin transport properties through two T-shaped three-quantum-dot molecules embedded in an Aharonov-Bohm（A-B） interferometer. By using the Keldysh non-equilibrium Green＇s function technique, the photon-assisted spin-dependent average current is analyzed. The T-shaped three-quantum-dot molecule A-B interferometer exhibits excellent controllability in the average current resonance spectra by adjusting the interdot coupling strength, Rashba spin-orbit coupling strength, magnetic flux, and amplitude of the time-dependent external field.Efficient spin filtering and multiple electron-photon pump functions are exploited in the multi-quantum-dot molecule A-B interferometer by a time-modulated external field.

Observation of electron–phonon coupling and linear dichroism in PL spectra of ultra-small CsPbBr_(3) nanoparticle solution

Blue-emission(~480 nm)CsPbBr_(3) nanoparticles with ultra-small size(~2.1 nm)are synthesized using the liquid nitrogen freezing with the ligand of dodecylbenzene sulfonic acid(DBSA).Asymmetric narrow emissions at the low energy side,with the full width at half-maximum of~20 nm,are observed in solution and film at room temperature.The spectral asymmetry is mainly ascribed to phonon vibronic replica with averaged phonon energy of~40 meV.Moreover,exciting this CsPbBr_(3) nanoparticles solution using linearly polarized 6 ns pulsed laser at 355 nm,we observe polarized emission with polarization degree(P_(PL))of~7%,and P_(PL) decreases more than 20%in the vibronic progression.However,the P_(PL) goes to zero in frozen solutions as well as in films.Thus we speculate the polarized emission is due to the photoinduced re-alignment of nanoparticles,and the diminished P_(PL) at the phonon side band may be due to the non-adiabatic electronic-to-vibronic transitions.The novel phenomena from the ultra-small CsPbBr_(3) nanoparticle demonstrated in this work may provide fundamental insights into its photophysics with direct implications for optoelectronics.

Intermolecular electronic coupling of 9-methyl-9H-dibenzo[a,c]carbazole for strong emission in aggregated state by substituent effect

Bright emission of organic luminogens at aggregated state has attracted increasing attention for their potential applications in opto-electronic devices and bio-/chemo-sensors.In this article,upon the introduction of different substituents(Br,Ph and TPh)to the large conjugated core of 9-methyl-9H-dibenzo[a,c]carbazole(DBC)moiety,the resultant luminogens demonstrated PL quantum yields in solid state ranging from 4.81%to 47.39%.Through the systematic investigation of molecular packing,together with theory calculation,the strong intermolecular electronic coupling in the dimers is proved as the main factor to the bright emission in the solid state.The results afforded a new avenue to investigate the intrinsic relationship among the molecular structures,packing modes and emission properties.

Orbital-regulated interfacial electronic coupling endows Ni3N with superior catalytic surface for hydrogen evolution reaction

The interstitial structure and weak Ni-N interaction of Ni3N lead to high unoccupied d orbital energy and unsuitable orbital orientation,which consequently results in weak orbital coupling with H2O and slow water dissociation kinetics for alkaline hydrogen evolution catalysis.Herein,we successfully lower the unoccupied d orbital energy of Ni3N to strengthen the interfacial electronic coupling by employing the strong electron pulling capability of oxygen dopants.The prepared O-Ni3N catalyst delivers an overpotential of 55 mV at 10 mA cm−2,very close to the commercial Pt/C.Refined structural characterization indicates the oxygen incorporation can decrease the electron densities around the Ni sites.Moreover,density functional theory calculation further proves the oxygen incorporation can create more unoccupied orbitals with lower energy and superior orientation for water adsorption and dissociation.The concept of orbital-regulated interfacial electronic coupling could offer a unique approach for the rational design of hydrogen evolution catalysts and beyond.

Self-consistent Field Crystal Orbital Study on One-dimensional C_(60)Polymer

Ｓｅｌｆ┐ｃｏｎｓｉｓｔｅｎｔＦｉｅｌｄＣｒｙｓｔａｌＯｒｂｉｔａｌＳｔｕｄｙｏｎＯｎｅ┐ｄｉｍｅｎｓｉｏｎａｌＣ６０Ｐｏｌｙｍｅｒ＊ＨＵＡＮＧＹｕａｎ－ｈｅ＊＊，ＣＨＥＮＧｕａｎｇ－ｊｕａｎｄＬＩＵＲｕｏ－ｚｈｕａｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＣｈ...

Binuclear Ruthenium Complexes with Benzo[1,2-b;4,5-b＇]- dithiophene Analogues as Bridge Ligands： Syntheses, Characterization and Notable Difference on Electronic Coupling

Diruthenium ethynyl complexes 1--3 （1： 1,5-dithia-s-indacene-4,8-dione; 2： 4,8-diethoxybenzo[1,2-b：4,5- b＇]dithiophene; 3： 4,8-didodecyloxybenzo[1,2-b：4,5-b＇]dithiophene） have been synthesized by incorporating the re- spective conjugated heterocyclic spacer and characterized by NMR and elemental analysis. The effects of bridge ligands＇ properties on electronic coupling between redox-active ruthenium terminal groups were investigated by electrochemistry, UV/vis/near-IR and IR spectroelectrochemistry combined with density functional theory （DFT） and time-dependent DFT calculations. Electrochemistry results indicated that complexes 1--3 exhibit two fully re- versible oxidation waves, and complexes 2 and 3 with electron-rich and π-conjuagted bridge ligands are character- ized by excellent electrochemical properties. Furthermore, the larger v（C≡C） separation from the IR spectroelec- trochemical results of 2 and 3 and the intense NIR absorption features of singly oxidized species 2＋ and 3＋ re- vealed that their molecular skeletons have superior abilities to delocalize the positive charge. The spin density dis- tribution from DFT calculations proved the conclusions of this study.

Synthesis and Characterization of Lanthanide Complexes Involving Cyclopentadienyl and Benzohydroximic Acid Ligand

The glasses of 59 5H 3BO 3 40XF n 0 5Eu 2O 3 (X=Ca, Mg, Y, Pb, n =2 or 3) were prepared. The measurement of phonon sideband was performed. The higher energy range of phonon sideband spectra was fitted by Gaussian function, and the electron phonon coupling constant was calculated. The decreasing order of electron phonon coupling constant is from CaF 2, YF 3, MgF 2 to PbF 2, and the phonon sideband spectra are coincide with Raman scattering spectra.