Unusual Charge Transport and Spin Response of Doped Bilayer Triangular Antiferromagnets

Within the t-J model, the charge transport and spin response of the doped bilayer triangular antiferromagnetare studied by considering the bilayer interaction. Although the bilayer interaction leads to the band splitting in theelectronic structure, the qualitative behaviors of the physical properties are the same as in the single layer case. Theconductivity spectrum shows the low-energy peak and unusual midinfrared band, the temperature-dependent resistivityis characterized by the nonlinearity metallic-like behavior in the higher temperature range and the deviation from themetallic-like behavior in the lower temperature range and the commensurate neutron scattering peak near the half-fillingis split into six incommensurate peaks in the underdoped regime, with the incommensurability increasing with the holeconcentration at lower dopings, and saturating at higher dopings.

Indications of c-axis Charge Transport in Hole Doped Triangular Antiferromagnets

The c-axis charge transport of the hole doped triangular antiferromagnet is investigated within the t-J model by considering the incoherent interlayer hopping. It is shown that the c-axis charge transport of the hole doped triangular antiferromagnet is essentially determined by the scattering from the in-plane fluctuation. The c-axis conductivity spectrum shows a low-energy peak and the unusual high-energy broad band, while the c-axis resistivity is characterized by a crossover from the high temperature metallic-like behavior to the low temperature insulating-like behavior, which is qualitatively consistent with those of the hole doped square lattice antiferromagnet.

Charge Transport Properties of Tetrabenz[a,c,h,j]-anthracene Derivatives

Charge transport properties of F, OH, OCH3, SH and SCH3-substituted tetra- benz[a,c,h,j]- anthracene derivative molecules have been investigated theoretically at the B3LYP/6-31G＊＊ level using Marcus theory. The results showed that at 300 K, the hole or electron transport capability of F or SH-substituted molecules was better obviously than that of OH or OCH3-substituted molecules, The electron transport capability of SCH3-substituted and F or SH-substituted molecules was superior to their hole transport capability, respectively. F, SH or SCH3-substituted tetrabenz[a,c,h,j]-anthracene derivative molecules can be used as electron transport materials.

Tuning crystal orientation and charge transport of quasi-2D perovskites via halogen-substituted benzylammonium for efficient solar cells

Quasi-two-dimensional(quasi-2D)perovskites with high stability usually suffers from poor device efficiency.Chemical tuning of the spacer cations has been an effective strategy to achieve efficient and stable quasi-2D perovskite solar cells.Here,we demonstrate that 3-halogon-substituted benzylammonium iodide(3X-BAI,X=F,Cl,Br,I)can significantly affect the orientation of low-dimensional perovskites and charge transport from perovskite to hole extraction layer,as well as device performance.With 3Br-BAI,we achieve the highest device efficiency of 13.21%for quasi-2D perovskites with a nominal n=3 average composition.Our work provides a facile approach to regulate vertical crystal orientation and charge transport via tuning the molecular structure of organic spacer toward high performance quasi-2D perovskite solar cells.

Theoretical Investigation on the Charge Transport Properties of 2,5-Di(cyanovinyl)-thiophene/furan with the Kinetic Monte Carlo Method

Exploring, designing, and synthesizing novel organic field-effect transistor （OFET） materials have kept an important and hot issue in organic electronics. In the current work, the charge transport properties for 2,5-di（cyanovinyl）thiophene/furan crystal associating two pentafluorophenyl units linked via the azomethine bond, CTE and CFE have been theoretically investigated by means of density functional theory （DFT） calculations coupled with the incoherent charge-hopping mechanism and the kinetic Monte Carlo simulation. Results show that these two compounds possess remarkably low-lying HOMO （-7.0 eV） and LUMO （-4.0 eV） levels, as well as large electron affinities （〉 3.0 eV）, which indicate their high stability exposed to air as promising OFET materials. However, the ph value at room temperature （T = 300 K） is predicted to be 2.058x10^7 cm26Vl·s-1, and the is as low as 9.834^10-8 cm2-V-l.s-1 for CFT crystal. Meanwhile, these two values are 7.561 x 10-8 and 8.437 x 10-8 cm2.V-I.s-1 for the CFE crystal, respectively. Furthermore, the simulation of angle-dependent mobility in the a-b, a-c, and b-c crystal planes shows that the charge transport in CTE and CFE crystals is remarkably anisotropic, which maybe is helpful for the fabrication of high-performance OFET devices.

Charge Transport in Bifidobacterium animalis subsp.lactis BB-12 under Various Atmospheres

The influence of relative humidity (RH) on quasistatic current-voltage (I-V) characteristics of Bifidobacterium animalis subsp. lactis BB-12 thin layers was studied for the first time. The value of electrical conductivity in 75% RH was found to be in the order of 10-7 (ohm·cm)-1, which was 106 orders of magnitude higher than that observed in dry atmosphere. It was concluded that RH played a key role in hysteresis behavior of the measured (I-V) characteristics. FTIR measurements showed that under water moisture environment, the associated bonds between amine and carboxyl group were greatly strengthened that was the source of free charge carries after ionization. The surface charge of Bifidobacterium animalis subsp. lactis BB-12 was found to be negative by zeta potential measurements, claiming that electrons were the charge carriers.

Influence of shape effect on dynamic surface charge transport mechanism of cellular electret after corona discharge

Surface charge accumulation and transport on cellular polypropylene play an important role in nanogenerators,which could have a potential impact on energy harvesting and wearable devices for zero carbon energy systems and the internet of things.Different shapes have different charge accumulation and decay characteristics of the polymer.Therefore,we studied the influence of the sample’s shape on the surface charge decay by experiment and modeling.The surface potential of square and circular cellular polypropylene was measured by a two-dimensional surface potential measurement system with electrostatic capacitive probe.The experimental result shows that the surface potential distribution of the square sample dissipates non-uniformly from the bell shape to a one-sided collapsed shape,while that of the circular sample dissipates uniformly from the bell shape to the crater-like shape.Moreover,the simulated results of the initial surface potential distributions of the square and circular cellular polypropylene are consistent with the experimental results.The investigation demonstrates that the charge transport process is correlated with the shape of the sample,which provides significant reference for designing electret material used for highly efficient nanogenerators.

Influence of charge transport layer on the crystallinity and charge extraction of pure tin-based halide perovskite film

As one of the most compelling photovoltaic devices, halide perovskite (PVK) solar cells have achieved a new surprising record power conversion efficiency (PCE) of 25.8%in 2021 [1]. This demonstrates the great potential of halide PVK solar cells as a highly competitive substitute to replace silicon-based solar cells in the photovoltaic market [2–6].

Crucial role of charge transporting layers on ion migration in perovskite solar cells

The device preconditioning dependent hysteresis and the consequential performance degradation hinder the actual performance and stability of the perovskite solar cells. Ion migration and charge trapping in the perovskite with large contribution from grain boundaries are the most common interpretations for the hysteresis. Yet, the high performing devices often include intermediate hole and electron transporting layers, which can further complicate the dynamical process in the device. Here, by using Kelvin Probe Force Microscopy and Confocal Photoluminescence Microscopy, we elucidate the impact of chargetransporting layers and excess MAI on the spatial and temporal variations of the photovoltage on the MAPbI3-based solar cells. By studying the devices layer by layer, we found that the light-induced ion migration occurs predominantly in the presence of an imbalanced charge extraction in the solar cells, and the charge transporting layers play crucial role in suppressing it. Careful selection and processing of the electron and hole-transporting materials are thus essential for making perovskite solar cells free from the ion migration effect.

Charge Transport Processes of Immobilized Heteropolyanions at Self-assembled Monolayer Modified Gold Electrode by Electrochemical Quartz Crystal Microbalance Measurement

The in situ electrochemical quartz crystal microbalance（EQCM） technique was used to investigate the ion transport of immobilized heteropolyanions at a self-assembled monolayer（SAM） modified gold electrode during electrochemical redox process.A mixed transfer method was presented to analyse the abnormal change of resonant frequency based on the simultaneous insertion/extraction of different ions.The results indicate that the migration of HSO4-anions was indispensable in the redox process of the heteropolyanions in a 1 mol/L H2SO4 solution and played a key role in the abnormal change of the resonant frequency.Such a change was attributed to different packing densities derived by means of differently immobilized methods.

Coherent charge transport in ferromagnet/semiconductor nanowire/ferromagnet double barrier junctions with the interplay of Rashba spin-orbit coupling, induced superconducting pair potential,and external magnetic field

By solving the Bogoliubov-de Gennes equation, the influence of the interplay of Rashba spin-orbit coupling, induced superconducting pair potential, and external magnetic field on the spin-polarized coherent charge transport in ferromagnet/semiconductor nanowire/ferromagnet double barrier junctions is investigated based on the Blonder-Tinkham-Klapwijk theory. The coherence effect is characterized by the strong oscillations of the charge conductance as a function of the bias voltage or the thickness of the semiconductor nanowire, resulting from the quantum interference of incoming and outgoing quasiparticles in the nanowire. Such oscillations can be effectively modulated by varying the strength of the Rashba spin-orbit coupling, the thickness of the nanowire, or the strength of the external magnetic field. It is also shown that two different types of zero-bias conductance peaks may occur under some particular conditions, which have some different characteristics and may be due to different mechanisms.

Phase transition and charge transport through a triple dot device beyond the Kondo regime

Semiconductor quantum dot structure provides a promising basis for quantum information processing, within which to reveal the quantum phase and charge transport is one of the most important issues. In this paper, by means of the numerical renormalization group technique, we study the quantum phase transition and the charge transport for a parallel triple dot device in the strongly correlated limit, focusing on the effect of inter-dot hopping t beyond the Kondo regime. We find the quantum behaviors depend closely on the initial electron number on the dots, and the present model may map to single,double, and side-coupled impurity models in different parameter spaces. An orbital spin-1/2 Kondo effect between the conduction leads and the bonding orbital, and several magnetic-frustration phases are demonstrated when t is adjusted to different regimes. To understand these phenomena, a canonical transformation of the energy levels is given, and important physical quantities with respect to increasing t and necessary theoretical discussions are shown.

Charge transport in conducting polyaniline co-doped with sulfosalicylic acid and dodecylbenzoyl sulfonic acid

We prepared conducting polyaniline （PAn） co-doped with sulfosalicylic acid （SSA） and dodecylbenzoyl sultonic acid （DBSA） in micro-emulsive polymerization, and studied its charge transport behaviors based on the measurement of its electrical conductivity in the temperature range between 203 K and 298 K. The conductivity was found to increase with temperature, similar to the case in semiconductors. Analyzing the experimental data with three models, namely the charge-energy-limitedtunneling model, Kivelson model and the three-dimensional variable range hopping （3D-VRH） model demonstrated that these models all describe well the charge transport behaviors of PAn co-doped with SSA and DBSA within the mentioned temperature range. From calculation with the 3D-VRH model, the hopping distance of the conducting PAn is obviously larger than its localization length. The PAn doped with SSA and DBSA enjoys desirable crystallinity due to the co-doping of two functional sulfonic acids. The macroscopic conductivity may correspond to three-dimensional transport in the network of the bundles, and the metallic islands may be attributed to quasi-one-dimensional bundles.

Theoretical Study on the Charge Transport Properties of Coronene and Its Derivatives

Molecular structures, reorganization energies and charge transport matrix elements of coronene and its fluoro-, hydroxyl- and sulfhydryl-substituted derivatives have been studied at the B3LYP/6-31G＊＊ level. Based on the semi-classical model of electron transfer, charge transport rate constants of the title molecules have been calculated. The results indicate that the coronene molecule is helpful to the transport of negative charge, and the transport rate of positive charge is between those of hexaazatriphenylene and triphenylene.

A Quantum Chemical Screening of Two Imidazole-Chalcone Hybrid Ligands and Their Pd, Pt and Zn Complexes for Charge Transport and Nonlinear Optical (NLO) Properties: A DFT Study

A quantum chemical screening of two imidazole-based chalcone ligands: 2- [1-(3-(1H-imidazol-1-yl)propylimino)-3-(phenylallyl)]phenol and 2-[1-(3-(1H- imidazol-1-yl)propylimino)-3-4-nitrophenylallyl]phenol (hereinafter referred to as HL1 and HL2 respectively) and their Pd, Pt and Zn chelates for charge transport and nonlinear optical (NLO) properties, is reported via dispersion- corrected density functional theory (DFT-D3) and time-dependent DFT (TD- DFT) methods. From our results, Pd and Pt complexes have been observed to show excellent hole-transport properties, owing to their very small reorganization energies. The light extraction efficiency of the HL1-Pt complex was deduced to be particularly impressive, thus suitable for the manufacture of hole transport layer in violet light emitting diodes (LEDs). Moreover, redox potentials and chemical stability studies have enabled us to validate the greater stability in moisture (towards oxidation), of HL2 complexes compared to their HL1 counterparts. The first and second hyperpolarizabilities of both ligands and their complexes have been found to be outstandingly higher than those of the push-pull prototypical, para-nitroaniline by factors of up to 12 in the case of HL2. These compounds, with the exception of the HL2-Pt complex, are thus interesting candidates having wide transparency tradeoffs for NLO efficiency in the manufacture of optoelectronic and photonic devices capable of second and third-order NLO response. Finally, metal chelation has been established to enhance the NLO response of all the chalcone-based imidazole ligands investigated as a result of metal-ligand charge transfer and ligand- metal charge transfer electronic transitions identified in the resulting complexes with the exception of the zinc complexes.

Enhanced charge transport in 2D inorganic molecular crystals constructed with charge-delocalized molecules

Outstanding charge transport in molecular crystals is of great importance in modern electronics and optoelectronics.The widely adopted strategies to enhance charge transport,such as restraining intermolecular vibration,are mostly limited to organic molecules,which are nearly inoperative in 2D inor-ganic molecular crystals currently.In this contribution,charge transport in 2D inorganic molecular crystals is improved by integrating charge-delocalized Se8 rings as building blocks,where the delocalized electrons on Se8 rings lift the intermolecular orbitals overlap,offering efficient charge transfer channels.Besides,α-Se flakes composed of charge-delocalized Se8 rings possess small exciton binding energy.Benefitting from these,α-Se flake exhibits excellent photodetection performance with an ultrafast response rate(�5μs)and a high detectivity of 1.08�1011 Jones.These findings contribute to a deeper under-standing of the charge transport of 2D inorganic molecular crystals composed of electron-delocalized inorganic molecules and pave the way for their poten-tial application in optoelectronics.

Discharge mode and particle transport in radio frequency capacitively coupled Ar/O_(2) plasma discharges

Simulations are conducted on capacitively coupled Ar/O_(2)mixed gas discharges employing a one-dimensional fluid coupled with an electron Monte Carlo(MC)model.The research explores the impact of different O_(2)ratio and pressures on the discharge characteristics of Ar/O_(2)plasma.At a fixed Ar/O_(2)gas ratio,with the increasing pressure,higher ion densities,as well as a slight increase in electron density in the bulk region can be observed.The discharge remains dominated by the drift-ambipolar(DA)mode,and the flux of O(3P)at the electrode increases with the increasing pressure due to higher background gas density,while the fluxes of O(1D)and Ardecrease due to the pronounced loss rate.With the increasing proportion of O_(2),a change in the dominant discharge mode from a mode to DA mode can be detected,and the O_(2)-associated charged particle densities are significantly increased.However,Ar+density shows a trend of increasing and then decreasing,while for neutral fluxes at the electrode,Arflux decreases,and O(3P)flux increases with the reduced Ar gas proportion,while trends in O(1D)flux show slight differences.The evolution of the densities of the charged particle and the neutral fluxes under different discharge parameters are discussed in detail using the ionization characteristics as well as the transport properties.Hopefully,more comprehensive understanding of Ar/O_(2)discharge characteristics in this work will provide a valuable reference for the industry.

Charge Transport in Disordered Graphene-Based Low Dimensional Materials

Two-dimensional graphene,carbon nanotubes,and graphene nanoribbons represent a novel class of low dimensional materials that could serve as building blocks for future carbon-based nanoelectronics.Although these systems share a similar underlying electronic structure,whose exact details depend on confi nement effects,crucial differences emerge when disorder comes into play.In this review,we consider the transport properties of these materials,with particular emphasis on the case of graphene nanoribbons.After summarizing the electronic and transport properties of defect-free systems,we focus on the effects of a model disorder potential(Anderson-type),and illustrate how transport properties are sensitive to the underlying symmetry.We provide analytical expressions for the elastic mean free path of carbon nanotubes and graphene nanoribbons,and discuss the onset of weak and strong localization regimes,which are genuinely dependent on the transport dimensionality.We also consider the effects of edge disorder and roughness for graphene nanoribbons in relation to their armchair or zigzag orientation.

Realizing compact three-dimensional charge transport networks of asymmetric electron acceptors for efficient organic solar cells

Asymmetry has been demonstrated an effective approach in recent years to tune the structural and energetic orders of nonfullerene electron acceptors(NFAs)to prepare efficient organic solar cells(OSCs).In this article,five asymmetric NFAs,namely C9BTP-BO-Th Cl-2F,C9BTP-BO-Cl-2F,C9BTP-BO-2Cl-2F,C7BTP-BO-2Cl-2F and C5BTP-BO-2Cl-2F possessing varied asymmetric end-groups and alkyl chains are synthesized to tune the charge transport networks formed within these NFAs.We found that the enhanced planarity in the asymmetric NFA can facilitate closerπ-πstacking distance in either the A-to-A or A-toD type NFA dimers,whilst the larger dipole moment can promote the formation of three-dimensional(3D)charge transport networks among NFAs.Taking those advantages,C7BTP-BO-2Cl-2F exhibit a compact 3D honeycomb network with a high packing coefficient of 72.1%and molecular packing density of 0.48 g/cm^(3),contributing to a superior power conversion efficiency of 18.0%when employing PM6 as the donor,with an open-circuit voltage of 0.85 V,short-circuit current of26.7 m A cm^(-2)and fill factor of 79.3%.Our work provides guidelines in engineering the end group and side chains of asymmetric NFAs to achieve compact charge transport networks for high efficiency OSCs.

A two-dimensional simulation method for investigating charge transport behavior in 3-D charge trapping memory

This work presents a self-consistent two-dimensional(2-D) simulation method with unified physical models for different operation regimes of charge trapping memory. The simulation carefully takes into consideration the tunneling process, charge trapping/de-trapping mechanisms, and 2-D drift-diffusion transport within the storage layer. A string of three memory cells has been simulated and evaluated for different gate stack compositions and temperatures. The simulator is able to describe the charge transport behavior along bitline and tunneling directions under different operations. Good agreement has been made with experimental data,which hence validates the implemented physical models and altogether confirms the simulation as a valuable tool for evaluating the characteristics of three-dimensional NAND flash memory.