Charge Layer Research Articles

Detection of Layer Charge Density in Layered Double Hydroxides and Studies on Host‐Guest Interactions

AbstractThe layer charge density of layered double hydroxides (LDHs) significantly affects interlayer spacing, the arrangement of interlayer anions and water molecules, thermal stability, as well as adsorption performance. However, traditional methods for evaluating the layer charge density of LDHs are complex, prone to large errors, and impacted by numerous factors, rendering these methods unable to facilitate direct comparisons of layer charge density across different LDH compositions. Consequently, this study proposes a novel approach based on the host‐guest supramolecular interactions in LDHs to investigate the layer charge density by analyzing changes in the position of the infrared absorption peaks of interlayer guest species. The shifts in infrared absorption peak positions are employed to assess the layer charge density of MgAl‐LDHs with varying molar ratios (M2+/M3+=2, 2.5, 3, 3.5, 4). The validity of using infrared peak position shifts is corroborated through a combination of techniques, including Raman spectroscopy, TG‐DTG, XRD, Zeta potential, and adsorption analyses. Furthermore, the layer charge density of NiAl, CoAl, MgFe, and NiFe‐LDHs are evaluated, confirming the universality of the infrared method. By ranking layer charge density of LDHs with different compositions and ratios, this study resolves the challenge of comparing LDHs with diverse layer compositions.

Solid-phase electrochemiluminescence immunosensing platform based on bipolar nanochannel array film for sensitive detection of carbohydrate antigen 125

Development of simple solid-phase electrochemiluminescence (ECL) immunosensor with convenient fabrication for high-performance detection of tumor biomarkers is crucial. Herein, a solid-phase ECL immunoassay was constructed based on a bipolar silica nanochannel film (bp-SNA) modified electrode for highly sensitive detection of carbohydrate antigen 125 (CA 125). Inexpensive and readily available indium tin oxide (ITO) electrode was used as the supporting electrode for the growth of bp-SNA. bp-SNA consists of a bilayer SNA film with different functional groups and charge properties, including negatively charged inner layer SNA (n-SNA) and positively charged outer layer SNA (p-SNA). The nanochannels of bp-SNA were used for the immobilization of ECL emitter tris(bipyridine)ruthenium(II), while the outer surface was utilized for constructing the immunorecognition interface. Due to the dual electrostatic interaction composed of electrostatic attraction from n-SNA and electrostatic repulsion from p-SNA, ECL emitter could be stably confined within bp-SNA, providing stable and high ECL signals to the modified electrode. After amino groups on the outer surface of bp-SNA were derivatized with aldehyde groups, recognition antibodies could be covalently immobilized, and an immunosensor was obtained after blocking nonspecific sites. When CA 125 binds to the antibodies on the recognition interface, the formed complex reduces the diffusion of the co-reactant tripropylamine (TPrA) to the supporting electrode, decreasing the ECL signal. Based on this mechanism, the constructed immunosensor can achieve sensitive ECL detection of CA 125. The linear detection range is from 0.01 to 100 U/mL, with a detection limit of 4.7 mU/mL. CA 125 detection in serum is also achieved. The construction immunosensor has advantages including simple and convenient fabrication, high stability of the immobilized emitter, and high selectivity, making it suitable for CA 125 detection.

Biofilm Microenvironment-Sensitive Anti-Virulent and Immunomodulatory Nano-on-Nanodroplets to Combat Refractory Biofilm Infection Through Toxin Neutralization and Phagocytosis.

Biofilm-associated wound infection is principally perceived as the bacterial defense mechanism that hinders antibiotic penetration, causes toxin impairment, and suppresses the immunological responses of the host immune system. Several antibiofilm agents have been developed, but the least of these agents can simultaneously cornerstone on the biofilm-associated immunosuppression and bacterial toxin-induced cellular dysfunction. Inspired by the fusogenic property of nanodroplets and immunomodulatory functions of metal nanoparticles, biofilm targeted anti-virulent immunomodulatory cationic nanoparticle shelled nanodroplets (C-AgND) is fabricated to completely disintegrate and eradicate the Staphylococcus aureus (S. aureus) biofilm. The specific binding of C-AgND neutralizes the negatively charged EPS layer, causing their destabilization followed by penetration of the nanoformulation into the biofilm matrix, killing the persister cells. Consequently, C-AgND eliminates the virulence property of the S. aureus biofilm through α-hemolysin neutralization. C-AgND promotes a strong immunomodulatory effect by polarizing macrophages into their M1 phenotype to induce phagocytosis of the disintegrated biofilm-released residual cells, rejuvenating the host's innate immune responses for the complete eradication of the biofilm. Moreover, the ex vivo skin wound infection model illustrates an excellent biofilm eradication efficacy of C-AgND in comparison to the commercial ones, rendering them to be a promising replacement of existing antibiofilm agents in clinical application.

CFD Modeling of HBI/SCRAP Melting in Industrial EAF and the Impact of Charge Layering on Melting Performance

The melting of scrap and hot briquetted iron (HBI) in an AC electric arc furnace (EAF) is simulated by an advanced 3D computational fluid dynamics (CFD) model that captures the arc heating, the scrap/HBI melting process, and the solid collapse mechanisms. The CFD model is used to simulate a scenario where charge layering and EAF power profiles are provided by a real EAF operation. CFD simulation of the EAF operation shows proper prediction of the charge melting when compared with standard industry practice. Namely, the CFD model predicts a 32.5%/67.5% ratio of solid/liquid steel at the beginning of refining, which approaches the 30%/70% ratio used in standard practice. Based on this prediction, the melting rate in the CFD results differs by 8.3% from actual EAF operation. The impact of charge layering on melting is also investigated. CFD results show that distributing charge material into a greater number of layers in the first bucket (10 layers as compared to 4) enhances the melting rate by 12%. However, including dense material at the bottom of the furnace deteriorates melting performance, reducing the impact of the number of layers of the charge. The CFD platform can be used to optimize the use of HBI/scrap in real EAF operations and to determine best recipe practices.

On the Parasitic Surface Adsorption of Pyrrolidinium and Phosphonium-based Ionic Liquids Preventing Accurate Differential Capacitance Measurements

Abstract Differential capacitance measurements are known to provide vital information regarding electrical double layer charging as well as interfacial structuring of ionic liquids and ionic liquid-based electrolytes. Several hurdles have prevented these types of measurements from becoming widely used, including the fact that there exists no real consensus as to how the measurement needs to be performed and the results analyzed. To add to the difficulty, some ionic liquids are known to display a hysteresis process, thus inducing measurement variabilities. In this report, we study pyrrolidinium and phosphonium-based ionic liquid electrolytes and show that hysteresis processes indeed exist and that these are mostly the consequence of cationic adsorption on the surface. Atomic force microscopy experiments reveal that pyrrolidinium-based systems display a much denser degree of ionic compaction at the interface, compared to the phosphonium-based systems, a fact that we correlate with the much more intense hysteresis measured in pyrrolidinium-based systems. We further propose a new method for the measurement of differential capacitance and compare it with other methods in use. It is found that the proposed method allows to minimize hysteresis phenomena, thereby leading to better accuracy.

Direct observation of space-charge-induced electric fields at oxide grain boundaries.

Space charge layers (SCLs) formed at grain boundaries (GBs) are considered to critically influence the properties of polycrystalline materials such as ion conductivities. Despite the extensive researches on this issue, the presence of GB SCLs and their relationship with GB orientations, atomic-scale structures and impurity/solute segregation behaviors remain controversial, primarily due to the difficulties in directly observing charge distribution at GBs. In this study, we directly observe electric field distribution across the well-defined yttria-stabilized zirconia (YSZ) GBs by tilt-scan averaged differential phase contrast scanning transmission electron microscopy. Our observation clearly reveals the existence of SCLs across the YSZ GBs with nanometer precision, which are significantly varied depending on the GB orientations and the resultant core atomic structures. Moreover, the magnitude of SCLs show a strong correlation with yttrium segregation amounts. This study provides critical insights into the complex interplay between SCLs, orientations, atomic structures and segregation of GBs in ionic crystals.

Characterization of the Lithium/Solid Electrolyte Interface in the Presence of Nanometer-thin TiOx Layers for All-Solid-State Batteries.

It is still unclear which role space charge layers (SCLs) play within an all-solid-state battery during operation with high current densities, as well as to which extent they form. Herein, we use a solid electrolyte with a known SCL formation and investigate it in a symmetric cell under non-blocking conditions with Li metal electrodes. Since the used LICGC™ electrolyte is known for its instability against lithium, it is protected from rapid degradation by nanometer-thin layers of TiOx deployed by atomic layer deposition. Close attention is given to the interfacial properties, as now additional Li+ can traverse through the interface depending on the applied bias potential. The interlayer's impedance response shows efficient lithium-ion conduction for low bias potentials and a diffusion-limiting effect towards high positive and negative potentials. SCLs grow up to a thickness of 5.1 μm. Additionally, estimating the apparent rate constant of the charge transfer across the interface indicates that the potentials where kinetics are hindered coincide with the widest SCLs. In conclusion, the investigation under higher steady-state currents was only possible because of the improved stability due to the interlayer. No chemo-physical failure could be observed after 800+ hours of cycling. However, an ex-situ SEM study shows a new phase at the interface, which grows into the electrolyte.

Embedding Reverse Electron Transfer Between Stably Bare Cu Nanoparticles and Cation-Vacancy CuWO4.

Cu nanoparticles (NPs) have attracted widespread attention in electronics, energy, and catalysis. However, conventionally synthesized Cu NPs face some challenges such as surface passivation and agglomeration in applications, which impairs their functionalities in the physicochemical properties. Here, the issues above by engineering an embedded interface of stably bare Cu NPs on the cation-vacancy CuWO4 support is addressed, which induces the strong metal-support interactions and reverse electron transfer. Various atomic-scale analyses directly demonstrate the unique electronic structure of the embedded Cu NPs with negative charge and anion oxygen protective layer, which mitigates the typical degradation pathways such as oxidation in ambient air, high-temperature agglomeration, and CO poisoning adsorption. Kinetics and in situ spectroscopic studies unveil that the embedded electron-enriched Cu NPs follow the typical Eley-Rideal mechanism in CO oxidation, contrasting the Langmuir-Hinshelwood mechanism on the traditional Cu NPs. This mechanistic shift is driven by the Coulombic repulsion in anion oxygen layer, enabling its direct reaction with gaseous CO to form the easily desorbed monodentate carbonate.

Unraveling Asymmetric Electrochemical Kinetics in Low-Mass-Loading LiNi1/3Mn1/3Co1/3O2 (NMC111) Li-Metal All-Solid-State Batteries

In this study, we fabricated a Li-metal all-solid-state battery (ASSB) with a low mass loading of NMC111 cathode electrode, enabling a sensitive evaluation of interfacial electrochemical reactions and their impact on battery performance, using Li1.3Al0.3Ti1.7(PO4)3 (LATP) as the solid electrolyte. The electrochemical behavior of the battery was analyzed to understand how the solid electrolyte influences charge storage mechanisms and Li-ion transport at the electrolyte/electrode interface. Cyclic voltammetry (CV) measurements revealed the b-values of 0.76 and 0.58, indicating asymmetry in the charge storage process. A diffusion coefficient of 1.5 × 10−9 cm2⋅s−1 (oxidation) was significantly lower compared to Li-NMC111 batteries with liquid electrolytes, 1.6 × 10−8cm2⋅s−1 (oxidation), suggesting that the asymmetric charge storage mechanisms are closely linked to reduced ionic transport and increased interfacial resistance in the solid electrolyte. This reduced Li-ion diffusivity, along with the formation of space charge layers at the electrode/electrolyte interface, contributes to the observed asymmetry in charge and discharge processes and limits the rate capability of the solid-state battery, particularly at high charging rates, compared to its liquid electrolyte counterpart.

Blue energy conversion utilizing smart ionic nanotransistors

The use of concentration gradients across nanofluidic membranes for energy generation presents a novel and sustainable approach to power production. This study investigates the impact of ion nanotransistor configurations on ion transport and energy generation. Two types of cylindrical symmetrical nanotransistors, PNP and NPN, were tested. Using the finite element method, the Poisson-Nernst-Planck and Navier-Stokes equations were solved to evaluate how the configuration of soft layers, concentration ratios, and charge density influence energy output. Results show that the NPN configuration consistently outperforms the PNP setup in energy production, with energy generation ranging from 40pW to 56pW, compared to 35pW to 43pW for the PNP structure, when soft layer charge density increase from 25mol/m3 to 100mol/m3. The superior performance of the NPN arrangement is attributed to its higher electrostatic potential and enhanced ion mobility. These findings underscore the potential of NPN nanotransistor configurations for optimizing energy generation as well as water desalination in nanofluidic systems.

Double modulation of the electric field in InGaAs/Si APD by groove rings for the achievement of THz gain-bandwidth product

Abstract Avalanche photodiode (APD) is commonly used as a receiver in optical communication and light detection and ranging (LIDAR), offering highly sensitive photodetection capabilities. A key strategy for improving the gain-bandwidth product (GBP) of the APD involves the optimization of the electric field distribution using the charge layer. However, traditional modulation methods to adjust the carrier transport and avalanche process using the charge layer often face challenges (inefficiency and non-uniformity). An InGaAs/Si APD based on the wafer bonding method with a GBP up to 1.03 terahertz (THz) is reported theoretically in this work. The charge layer and groove rings are inserted at the InGaAs/Si bonded interface to modulate the electric field in the APD effectively, demonstrating low dark current and reduced avalanche bias of the device. This approach induces a dramatic and rapid variation of the electric field at the interface while reducing the gradient of the electric field in the multiplication layer. Additionally, the indirect impact of the groove ring on mitigating the adverse effects of the lattice mismatch is pointed out, and the optimal doping concentration range of the charge layer is identified to enhance the modulation effect of the electric field for stronger impact ionization. These findings provide valuable insights for the next-generation InGaAs/Si APDs with high GBP for high-speed data transmission.

Role of ex-situ HfO2 passivation to improve device performance and suppress X-ray-induced degradation characteristics of in-situ Si3N4/AlN/GaN MIS-HEMTs

The role of ex-situ HfO2 passivation in in-situ Si3N4/AlN/GaN-based metal–insulator–semiconductor high-electron-mobility transistors (MIS-HEMTs) to improve the device performance and protect the device from severe degradation under high-energy X-ray irradiation has been investigated. Here, the root cause and mechanism for the degradation have been studied utilizing different material/device characterizations. X-ray photoelectron spectroscopy results suggest that several Si-N bonds in stoichiometric Si3N4 and Hf-O bonds in HfO2 passivation film can be broken under X-ray irradiation, where numerous charges might be trapped easily and deteriorate the interface quality. Furthermore, due to the generation of chemical vacancies under X-ray, a band tail near the edge of valence band maximum in Si3N4 and HfO2 films can be created. The obtained results suggest that MIS-HEMT fabricated with an atomic layer deposited (ALD)-HfO2 (MIS-HEMT B) has relatively greater performance compared to MIS-HEMT fabricated without ex-situ HfO2 (MIS-HEMT A) according to the higher maximum drain current (Idmax), peak transconductance (gmmax) and lower current collapse, denoting the effectiveness of ALD-HfO2 to passivate the surface traps. It is noticed that X-ray irradiation induces numerous negative charges in the dielectric layers and degrades the device performance. Interestingly, after X-ray irradiation, the degradation rates in Idmax, gmmax, and current collapse are significantly lower in MIS-HEMT B compared to MIS-HEMT A, suggesting the potential irradiation hardening mechanism of ALD-HfO2 to protect the MIS-HEMTs from unexpected degradations during X-ray irradiation. Finally, these results emphasize the importance of high-quality dielectric films in MIS-HEMTs to enhance the device performance and safeguard the device under high-energy irradiation, especially in the space environment.

Insight into the effect of Gd-doping on conductance and thermal matching of CeO2 for solid oxide fuel cell

GDC (Gd-doped CeO2) play a dual role in solid oxide fuel cell (SOFC), effectively blocking the reaction between YSZ (Y2O3-doped ZrO2) electrolyte and high-performance cathode materials such as La0.6Sr0.4Co0.2Fe0.8O3-δ, and improving the low-temperature oxygen ion transport in composite cathodes. It is crucial to systematically investigate the influencing mechanism of Gd-doping on conductance and thermal matching of CeO2 for high-efficiency and stable SOFC. In this paper, the physical phase, morphology and electrochemical performance of Ce1-xGdxO2-δ (x=0.1, 0.15, 0.2, 0.25) were characterized, and the thermal matching between GDC and other cell components was investigated by finite-element thermal stress calculations and cold-heat-cycling tests. The results indicate that Ce0.8Gd0.2O2-δ obtains the optimum conductivity, whether in the low temperature segment affected by the grain boundary with the space charge layer, or in the activation energy controlled medium temperature segment. Moreover, the finite-element calculation shows that the thermal stresses of the electrolyte facing the barrier layer and the barrier layer facing the cathode decrease gradually with the increase of Gd-doping. Consequently, the cell with Ce0.8Gd0.2O2-δ applied to the composite cathode and the barrier layer presents the optimal output performance of 0.87 W⋅cm-2 at 750 °C, and the cell performance decreased by only 1.15% after 50 thermal cycles between 25-800 °C. This is significant for improving the long-term operational stability of SOFC under thermal cycling conditions.

Convolution Analysis in Electrodeposition

Convolution is a well established method for data analysis for electrochemical processes where both product and reactants are soluble. Advantages of convolution analysis include (a) facile evaluation of kinetic and system parameters, (b) ready corrections for nonfaradaic uncompensated resistance and double layer charging, (c) track of surface concentrations with time, independent of the voltage perturbation sequence, and (d) ease of convolution calculation from digitized current data. Here, equations are derived for convolution of electrodeposition data and a data analysis protocol is presented. Advantages are found for convolution analysis in electrodeposition. Parameters that can be determined from convolution analysis in electrodeposition are standard heterogeneous rate constant k 0 and exchange current density j 0, transfer coefficients α and β, formal potential E0′ , resistance to charge transfer, and diffusion coefficient of the solution soluble reactant D M . Convolution in electrodeposition is illustrated for silver deposited from an ionic liquid onto a glassy carbon electrode, where experimental data are tracked cyclic voltammetrically.

DETERMINATION OF OPTIMAL PARAMETERS OF SINTERING OF ROLLING SCALE

This article presents the results of studies conducted to determine the optimal parameters of sintering of rolled scale in a mixture with iron-containing steelmaking waste. The conducted studies of sintering of rolled scale have shown that the gas permeability of the charge depends on a number of physical properties, the size and shape of the grains, the amount of return, the height of the charge layer, and the moisture content of the charge. The initial gas permeability strongly depends on the degree of humidification of the agglomeration charge, especially when sintering small classes of materials under study. The maximum gas permeability of the charge is ensured with an optimal granulometric composition of the charge, which is characterized by an average equivalent diameter: the higher this indicator, the higher the gas permeability of the charge. The value of the surface tension reaches its maximum at a certain moisture content of the charge, which is the optimal moisture for this charge. By increasing the amount of return during agglomeration, the vertical sintering rate increases and the quality of the agglomerate improves. These factors lead to an increase in the productivity of sintering plants. According to the results of the study, the optimal parameters of the sintering sintering process of rolled scale in a mixture with iron-containing steelmaking waste were worked out. It is established that the optimal amount of return is the use of 20 % of the mass of the sintering charge at the optimal height of the sintered layer of 300 mm. As a result of the conducted research, the following optimal indicators were achieved: mechanical strength – 70.2 %, sintering rate – 28.7 mm/min, specific productivity – 1.75 t/m2·hour. Keywords: Rolling scale, agglomeration, optimal parameters, sintering, return, layer height.

Coaxial tribonegative yarn TENG with aromatic polyimide as charge entrapment layer for real-time edge ball assessment in cricket sports

Energy harvesting yarns working on triboelectric effect by converting mechanical energy into electricity for running wearable electronics as well as operating as self-powered sensors, are superb choices for wearable electronics of current and future generations. However, current yarn-based triboelectric nanogenerators (TENGs) designed through electrospinning process are limited in achieving higher outputs, comfort, mechanical strength, washability, and industrial scalability. In this study, we introduce a flexible and durable tribonegative yarn TENG (TNY) with an electrospun polyimide (PI) intermediate charge trapping layer between the electrode and electrospun superhydrophobic polyvinylidene difluoride (PVDF)/Poly(dimethylsiloxane) (PDMS). In this coaxial arrangement, the PI charge entrapment layer enabled the TNY to exhibit an output voltage of 14 V in a 2.5 cm length, compared to only 8 V for TNY without PI layer. The TNY can be successfully woven and knitted into electronic textiles (E-Textiles), with their outputs compared based on various knitted and woven patterns. The E-Textile maintained considerable outputs after washing and withstood 5000 Martindale abrasion cycles. The superhydrophobic behavior also enabled TNY to harvest water energy from a running tap. We demonstrated the potential of these E-Textiles for edge ball sensing in cricket sports in real-time by leveraging the benefits of triboelectrification, thereby avoiding the need for complex camera setups and sound systems for judging ball movements at ± 140 km/hr in real sports. We also employed E-Textiles for smart switch functions, which can be beneficial in smart systems. This study demonstrates the improved performance of yarn-based TENGs and further extends the applications of TENGs in sports analysis. It provides a facile and high-efficiency approach for designing triboelectric sensors, offering a cost-effective alternative to complex and expensive sports equipment.

Attaining superior performance in an aqueous hybrid supercapacitor based on N-Doped highly porous carbon spheres and N-S dual doped Co3O4

Cobalt oxide (Co3O4) has seen a significant interest for its application as an electrode for supercapacitors, due to its cost-effectiveness, high theoretical capacitance and outstanding redox activity. However, Co3O4 exhibits poor electrical conductivity and cycle life restricting its high-power energy storage applications. High porosity carbons are materials of choice for applications in electric double layer charge storage but suffer from poor energy densities due to limited charge storage capabilities. Here we propose a hierarchical functionalization strategy to develop N, S co-doped Co3O4 and N doped high porosity carbon micro-spheres for efficient and durable hybrid supercapacitor. Benefiting from the structural eminence, improved electrical conductivity and high quantity of N content, the heteroatom enriched N, S co-doped Co3O4 and N doped porous carbon spheres demonstrates superior electrochemical performance. Moreover, hybrid supercapacitor cell with N, S co-doped Co3O4 as a cathode and N doped porous carbon spheres as anode deliver a high specific energy of 52 Wh kg-1 at power density of 1462 W kg-1 coupled with the capacity retention of 95 % after 5,000 charge-discharge cycles.Therefore, by improving both anode and cathode simultaneously can be considered an effective approach to enhance energy storage capabilities of hybrid supercapacitors while maintain exceptionally high-power densities.

Know-How of the Effective Use of Carbon Electrodes with a through Axial Hole in the Smelting of Silicon Metal

This article describes elements of the know-how of using carbon electrodes produced using the technology of molding around a rod when smelting silicon metal. Application of our know-how will dramatically increase the competitiveness of silicon metal production. Experts’ concerns regarding the use of such electrodes were that such electrodes have a through axial hole. This significantly reduces the mechanical strength of such electrodes, which can presumably lead to problems associated with the breakage of the working side of the electrode, which is immersed in the smelting space of the furnace under the charge layer. Industrial testing of such electrodes was carried out in a 30 MVA furnace of “Tau-Ken Temir” LLP. During testing, we used an approach previously developed by our team for working with a furnace in the process of smelting silicon metal. In particular, we used an interval between top treatments of about 30 min and adhered to the principles of balanced smelting, i.e., provided a balance between the intensity of the uniform supply of the charge into the furnace and the current active electrical power. Industrial testing carried out over four weeks confirmed the stability of the operation of cheaper carbon electrodes with a through axial hole. The recovery of silicon into finished products was also improved to 88–89% and the specific energy consumption was reduced to 11.2–12.1 MWh/t of silicon metal from the initial value 14,752 MWh/t. Thus, we received additional evidence for the effectiveness of our approach in furnace operating compared to an approach based on the ultimate provision of gas and permeability of the furnace top due to excessively intense processing of the top and an uncontrolled, uneven supply of charge to the furnace.

Staged dendrite suppression for high safe and stable lithium-sulfur batteries

The unavoidable dendrite growth and shuttle effect have long been stranglehold challenges limiting the safety and practicality of lithium-sulfur batteries. Herein, we propose a dual-action strategy to address the lithium dendrite issue in stages by constructing a multifunctional surface-negatively-charged nanodiamond layer with high ductility and robust puncture resistance on polypropylene (PP) separator. The uniformly loaded compact negative layer can not only significantly enhance electron transmission efficiency and promote uniform lithium deposition, but also reduce the formation of dendrite during early deposition stage. Most importantly, under the strong puncture stress encountered during the deterioration of lithium dendrite growth under limiting current, the high ductility and robust puncture resistance (145.88 MPa) of as-obtained nanodiamond layer can effectively prevent short circuits caused by unavoidable lithium dendrite. The Li||Li symmetrical cells assembled with nanodiamond layer modified PP demonstrated a stable cycle of over 1000 h at 2 mA cm−2 with a polarization voltage of only 29.3 mV. Additionally, the negative charged layer serves as a physical barrier blocking lithium polysulfide ions, effectively mitigating capacity attenuation. The improved cells achieved a capacity decay of only 0.042% per cycle after 700 cycles at 3 C, demonstrating effective suppression of dendrite growth and capacity attenuation, showing promising prospect.

Photovoltage-Driven Photoconductor Based on Horizontal p-n-p Junction.

The photoconductive gain theory demonstrates that the photoconductive gain is related to the ratio of carrier lifetime to carrier transit time. Theoretically, to achieve higher gain, one can either prolong the carrier lifetime or select materials with high mobility to shorten the transit time. However, the former slows the response speed of the device, while the latter increases the dark current and degrades device sensitivity. To address this challenge, a horizontal p-n-p junction-based photoconductor is proposed in this work. This device utilizes the n-region as the charge transport channel, with the charge transport direction perpendicular to the p-n-p junction. This design offers two advantages: (i) the channel is depleted by the space charge layer generated by the p and n regions, enabling the device to maintain a low dark current. (ii) The photovoltage generated in the p-n junction upon light absorption can compress the space charge layer and expand the conductive path in the n-region, enabling the device to achieve high gain and responsivity without relying on long carrier lifetimes. By adopting this device structure design, a balance between responsivity, dark current, and response speed is achieved, offering a new approach to designing high-performance photodetectors based on both traditional materials and emerging nanomaterials.