Anode Contact Research Articles

GaN-based super-lattice Schottky barrier diode with low forward voltage of 0.81V

In this paper, we report a high-performance AlGaN/GaN Schottky barrier diode (SBD) based on super-lattice structure. The stacking of five AlGaN/GaN heterostructures yields a small sheet resistance ( R SH ) of 120 Ω/sq. The fully recessed anode structure is used to contact all the current channels, leading to a small turn-on voltage ( V ON ) of 0.44 V. Besides, the ohmic contact with a contact resistance ( R C ) of 0.17 Ω mm is obtained by etching the cathode region. The on-resistance ( R ON ) of the device is reduced by 63.8%, down to 1.7 Ω mm, and a forward voltage ( V F ) as low as 0.81 V is achieved. To the best of our knowledge, this V F is the lowest value among all the GaN SBDs. These results are superior to the conventional single heterojunction devices , showing the great potential of the GaN-based super-lattice structures for achieving low forward conduction losses. • The super-lattice structure yields a small sheet resistance, and the on-resistance of the device is reduced by 63.8%. • A contact resistance of 0.17 Ω mm is obtained by etching the cathode region with designed depth. • The fully recessed anode contacts all the current channels, leading to a small turn-on voltage of 0.44 V. • A forward voltage as low as 0.81 V and an on-resistance down to 1.7 Ω·mm have been achieved.

3D reconstruction of dynamic behaviors of vacuum arcs under transverse magnetic fields via computer tomography.

The transverse magnetic field (TMF) contacts make the vacuum arcs deviate from the axisymmetric structure, so complete spatiotemporal evolution information of the plasma cannot be obtained by adopting one- or two-dimensional (2D) diagnostic methods. To address the issues, computer tomography was introduced in this paper. First, a multi-angle diagnostic imaging system based on split fiber bundles was proposed, which used a high-speed camera to simultaneously acquire eight angles of the arc image over time. In addition, a tomography algorithm called the maximum likelihood expectation maximum with Split Bregman denoising was proposed to reconstruct the dynamic spatiotemporal characteristics of the arc under complex conditions. Then, the three-dimensional (3D) distribution of Cu i and Cr i particles inside the contact gap was obtained by adopting optical filters. The 3D distribution of the vacuum arc had shown an obvious asymmetrical pattern under the TMF contacts, and there was a ring-like aggregation zone inside the arc, which can cause severe ablation on the anode contacts. According to the reconstructed 3D distribution of Cu i and Cr i, it is found that the metal vapor was mainly concentrated near the electrode surface and showed a clear distribution of non-uniform aggregates, while the concentration of particles in the gap was low. Moreover, on the cathode surface, the cathode spots moved in the form of groups driven by the TMF, while the anode surface was ablated by the electric arc, and the metal vapor existed in the form of bands.

Исследование пространственной динамики включения лазера-тиристора (905 нм) на основе многопереходной гетероструктуры AlGaAs/InGaAs/GaAs

The switching on process spatial dynamics of a laser-thyristor based on an AlGaAs/InGaAs/GaAs heterostructure with a thin p-base has been studied. The heterostructure had a modified base with a middle-doped layer at the n-emitter, which makes it possible to increase the operating voltages in order to generate nanosecond current pulses. In laser thyristor pulsed sources based on the proposed heterostructure, a high degree of current flow region localization arising during turn on process of the device was demonstrated. Using the current localization regions luminescence, the propagation dynamics of the switched-on state was estimated. The anode contact sizes required for the nanosecond range pulsed current switches or laser emitters development are obtained.

A bare-photovoltaic tether for consumable-less and autonomous space propulsion and power generation

State-of-the-art electrodynamic tethers reach a steady electric current by using a bare segment to capture electrons passively from the ambient plasma (anodic contact) and an active electron emitter or a tether segment coated with a low-work-function material (cathodic contact) to emit electrons back and close the electrical circuit. This work proposes to take advantage of recent developments on thin-film solar cells and insert a photovoltaic (pv) tether segment in between the anodic and the cathodic contacts. Since thin-film solar cells can be folded and manufactured with any desired length and the same cross-section dimensions as the bare segment, i.e. width and thickness around few centimeters and tens of microns, the resulting device is compact and preserves bare tether simplicity. Detailed analysis of the current and voltage profiles throughout the tether shows that the electrical power introduced by the pv-segment into the tether-plasma circuit improves the performance and makes them less dependent on ambient conditions. The pv-segment decreases considerably the tether-to-plasma bias at the cathodic contact, thus opening the possibility to emit substantial current while using consumable-less electron emitters like thermionic and electron field emitters. The pv-segment also favors the current collection by increasing the tether-to-plasma bias at the bare segment. Propulsion and power generation applications and alternative architectures of bare-pv tethers are briefly discussed.

Synthesis and processing of SOFC components for the fabrication and characterization of anode supported cells

In this article, it is intended to evaluate the performances of previously synthesized different nanometric compounds as SOFC components under real conditions. For this purpose, anodic supports SOFCs have been manufactured in different configurations.The compounds NiO-(Y2O3)0.08(ZrO2)0.92 (NiO–YSZ), (Y2O3)0.08(ZrO2)0.92 (YSZ), Sm0.2Ce0.8O1.9 (SDC), La0.6Sr0.4FeO3 (LSF) and LaNi0.6Fe0.4O3 (LNF) were used as anode support, electrolyte, barrier, cathode and contact layer, respectively. To obtain the cells, the anode supports were produced by uniaxial pressing and the remaining layers were added using the airbrush technique, assembling them by different sintering processes. The cells developed have been electrochemically tested in a temperature range between 750 and 865°C. Additionally, degradation tests have been carried out under constant current. Moreover, to characterize the microstructure of the cells, a scanning electron microscope (SEM) equipped with an energy dispersive X-ray spectroscopy (EDX) analyzer has been used.The results obtained show that the incorporation of cathode and contact layers increases the power densities and decreases the total resistances of the cells with respect to the cell without cathode, especially with the addition of the LNF contact layer. Despite the improvement obtained, more tests have to be carried out in order to optimize the performance of SOFC devices in degradation tests.

Numerical investigation on the influence of circuit breaker structure parameters on vacuum arc behaviors

In a switchgear, an external transverse magnetic field (ETMF) is generated by the U type loop consisting of the vacuum interrupter, external busbar and conductive rod connected to the vacuum interrupter. The ETMF will make the vacuum arc deflected and strengthen the contraction of the arc. This can increase the probability of breaking failure. To weaken the adverse effect of the ETMF, the real magnetic field data of the arc area with different structure parameters when the length of conductive rod, external busbar and phase distance is changed are obtained by establishing simulation model in this paper. Taking the real magnetic field data as the boundary condition, this paper obtains the typical parameters of the vacuum arc plasma with different structure parameters by using the established three-dimensional high-current vacuum arc magnetohydrodynamics model. The simulation results show that the ETMF makes the transverse magnetic field (TMF) of the arc area asymmetric, which leads to an arc deflection. Reducing the length of the conductive rod connected to the vacuum interrupter to 50 mm can effectively improve the asymmetry of the TMF caused by the EMTF, weaken the arc deflection phenomenon, make the distribution of the plasma parameters more uniform, and increases the utilization of the anode contact surface. Moreover, it can not only reduce the heat flux density into the anode as a whole, but also reduce the heat flux density in the high heat flux density area, so as to effectively reduce the degree of anode activity and improve the negative effects caused by the anode activity. The changes of other external structural parameters have less influence on the improvement of the vacuum arc deflection phenomenon. Increasing the phase spacing to 275 mm or reducing the length of the external bus bar to 100 mm can only slightly weaken the arc deflection.

Numerical Simulation and Analysis of Arc Anode Erosion Process with Electrode Rotation

A three-dimensional geometric model of anode contact of vacuum circuit breaker is established. Considering the influence of electrode rotation on vacuum arc and anode thermal process, a physical model of phase transformation process is established for the melting and evaporation of anode surface. The solid-liquid mixing area is treated by the description method of porous media, and the numerical simulation of anode thermal process is carried out. The conclusion is that with the increase of time, the anode surface temperature increases, molten pool development, molten pool depth deepening, in addition, with the increase of electrode speed, the highest temperature on the surface of the contact and the size of the molten pool were reduced, the temperature distribution more uniform. It provides theoretical basis for evaluating the breaking capacity of vacuum circuit breaker.

Ultra‐Low Dark Current Organic–Inorganic Hybrid X‐Ray Detectors

AbstractOrganic‐inorganic hybrid semiconductors are an emerging class of materials for direct conversion X‐ray detection due to attractive characteristics such as high sensitivity and the potential to form conformal detectors. However, existing hybrid semiconductor X‐ray detectors display dark currents that are 1000–10 000× higher than industrially relevant values of 1–10 pA mm−2. Herein, ultra‐low dark currents of <10 pA mm−2, under electric fields as high as ≈4 V µm−1, for hybrid X‐ray detectors consisting of bismuth oxide nanoparticles (for enhanced X‐ray attenuation) incorporated into an organic bulk heterojunction consisting of p‐type Poly(3‐hexylthiophene‐2,5‐diyl) (P3HT) and n‐type [6,6]‐Phenyl C71 butyric acid methyl ester (PC70BM) are reported. Such ultra‐low dark currents are realized through the enrichment of the hole selective p‐type organic semiconductor near the anode contact. The resulting detectors demonstrate broadband X‐ray response including an exceptionally high sensitivity of ≈1.5 mC Gy−1 cm−2 and <6% variation in angular dependence response under 6 MV hard X‐rays. The above characteristics in combination with excellent dose linearity, dose rate linearity, and reproducibility over a broad energy range enable these detectors to be developed for medical and industrial applications.

All-Solid-State Al – Graphene Hybrid Supercapacitor

With the recent growth of interest in wearable electronics, gel electrolytes or solid electrolytes of energy conversion devices such as batteries and capacitors have been actively studied. All-solid-state supercapacitor has advantages such as high power density, outstanding mechanical stability, and long cycle life. However, the low energy density of supercapacitor makes it difficult to replace the battery. Therefore, a hybrid supercapacitor combining a battery and a supercapacitor has been significantly attracted.In this study, aluminum as a battery electrode and graphene as a capacitor electrode were hybridized in a cell and ethyl acrylate and ionic liquid were used to make a polymer gel electrolyte. Aluminum has high energy density due to three-electron reaction and can be considered as a promising battery type electrode of a hybrid supercapacitor. Conversely, graphene is appropriate for capacitor type electrodes owing to its large specific surface area (~2675 m2 g-1) and high theoretical capacity (550 F g-1 ). With the increase of charge/discharge cycling, the dissolution and deposition reactions of aluminum were repeated and the contact of the aluminum anode and gel electrolyte decreases, which can result in a decrease in capacitance and cycle stability. Two strategic approaches were applied to improve the cell performance and charging-discharging behaviors were investigated with the variations of aluminum surface morphology. Firstly, aluminum metal was electropolished to remove the surface oxide film and applied as an anode. Secondly, thin aluminum metal film was prepared with electroplating and tested as an anode. Electrochemical Impedance Spectroscopy (EIS) was used to characterize the gel electrolyte and to measure the contact resistance between electrolyte and the surface-treated aluminum. SEM and XRD were used to analyze the aluminum surface structure.

Electrochemical Impedance Studies of Internal Short Circuits of Lithium-Ion Batteries Under Mechanical Abusive Conditions

Due to the high energy density and long lifetime, lithium-ion batteries (LIB) become ubiquitous energy storage systems for electric vehicle operations1. However, a higher energy density frequently results in a developed risk of thermal instability issues, where a series of heat-producing reactions can quickly occur, leading to fire and even explosions2. Due to the prevalent utilization in electric vehicles, battery abuse can hardly be avoided as LIB is exposed to many accidents, and mechanical abuse of various degrees of intensity often paves the way for internal short-circuiting of components through rupturing of separators3-4. Such battery failure induced by mechanical damage can lead to electrical and chemical hazards together with fire, which can result in danger to life, the environment, and the infrastructure and should therefore not occur in the field. The origin of such thermal-induced battery degradation certainly caused by short-circuiting of battery components mostly by direct contact of anode and cathode electrodes. To mitigate these issues and caution the electric vehicle drivers about thermal runaway events, the development of a diagnostic method to identify the damage mechanism under mechanical deformation and corresponding electrical behavior is essential.The onset of short circuits often characterized by a sharp increase in current, temperature, and rapid drop in voltage and set pass criteria as the absence of these potentially dangerous events as which may be enough for regular safety testing. Such events detected by a range of techniques including electrochemical impedance, incremental capacity-differential voltage, infra-red, tomography, etc5-7. However, it is challenging to design repeatable experiments that can emulate early-stage incubation of field ISC failure. Herein, we demonstrate resistance measurement by electrochemical impedance spectroscopy as an indicator for the detection of an internal short circuit of LIBs. The occurrence of ISC at different mechanical deformative conditions is evaluated through proper equivalent circuit model with multi-frequency and alternating voltage or current signal. The fitted results reveal that cathode-electrolyte interface resistance can be used to predict the onset of ISC due to mechanical abusive conditions. The obtained results demonstrate that impedance spectroscopy, together with a precise modeling parameter, provides information about the emergence of ISC and battery lifetime. Scrosati, B.; Garche, J., Lithium batteries: Status, prospects and future. Journal of power sources 2010, 195 (9), 2419-2430.Feng, X.; Ouyang, M.; Liu, X.; Lu, L.; Xia, Y.; He, X., Thermal runaway mechanism of lithium ion battery for electric vehicles: A review. Energy Storage Materials 2018, 10, 246-267.Wang, Q.; Ping, P.; Zhao, X.; Chu, G.; Sun, J.; Chen, C., Thermal runaway caused fire and explosion of lithium ion battery. Journal of Power Sources 2012, 208, 210-224.Zhu, X.; Wang, H.; Wang, X.; Gao, Y.; Allu, S.; Cakmak, E.; Wang, Z., Internal short circuit and failure mechanisms of lithium-ion pouch cells under mechanical indentation abuse conditions：An experimental study. Journal of Power Sources 2020, 455, 227939.Xiong, R.; Ma, S.; Li, H.; Sun, F.; Li, J., Toward a Safer Battery Management System: A Critical Review on Diagnosis and Prognosis of Battery Short Circuit. iScience 2020, 23 (4), 101010.Spielbauer, M.; Berg, P.; Ringat, M.; Bohlen, O.; Jossen, A., Experimental study of the impedance behavior of 18650 lithium-ion battery cells under deforming mechanical abuse. Journal of Energy Storage 2019, 26, 101039.Barai, A.; Uddin, K.; Dubarry, M.; Somerville, L.; McGordon, A.; Jennings, P.; Bloom, I., A comparison of methodologies for the non-invasive characterisation of commercial Li-ion cells. Progress in Energy and Combustion Science 2019, 72, 1-31.

Improving the Thermal Stability of Top‐Emitting Organic Light‐Emitting Diodes by Modification of the Anode Interface

AbstractTop‐emitting organic light‐emitting diodes (OLEDs) are of interest for numerous applications, in particular for displays with high fill factors. To maximize efficiency and luminance, molecular p‐doping of the hole transport layer (p‐HTL) and a highly reflective anode contact, for example, made from silver, are used. Atomic layer deposition (ALD) is attractive for thin film encapsulation of OLEDs but generally requires a minimum process temperature of 80 °C. Here it is reported that the interface between the p‐HTL and the silver anode of top‐emitting OLEDs degrades during an 80 °C ALD encapsulation process, causing an over fourfold reduction in OLED current and luminance. To understand the underlying mechanism of device degradation, single charge carrier devices are investigated before and after annealing. A spectroscopic study of p‐HTLs indicates that degradation is due to the interaction between diffusing silver ions and the p‐type molecular dopant. To improve the stability of the interface, either an ultrathin MoO3 buffer layer or a bilayer HTL is inserted at the anode/organic interface. Both approaches effectively suppress degradation. This work shows a route to successful encapsulation of top‐emitting OLEDs using ALD without sacrificing device performance.

19-element vertical cavity surface emitting laser arrays with inter-vertical cavity surface emitting laser ridge connectors

We achieve record concurrent combinations of bandwidth (18 GHz), optical output power (150 mW), and wall plug efficiency (30%) with a unique arrangement of 19-element, electrically parallel 980 nm vertical cavity surface emitting laser (VCSEL) arrays. We use a new two-dimensional, quasi honeycomb geometry with inter-VCSEL ridge connectors—made nonconducting by selective thermal oxidation—to improve heat dissipation and facilitate a single top surface anode contact. Via on-wafer probing we perform static and dynamic measurements over the wide temperature range of 23 °C to 85 °C and extract, report, and discuss key array figures-of-merit.

Two-way nonlinear mechanical-electrochemical-thermal coupled analysis method to predict thermal runaway of lithium-ion battery cells caused by quasi-static indentation

Recent thermal runaway accidents have caused concerns regarding the safety of lithium-ion batteries (LIBs). Because thermal runaway experiments are dangerous, numerical methods have garnered attention to investigate thermal runaway. Herein, a two-way nonlinear mechanical-electrochemical-thermal coupled analysis method is developed to analyze the internal short-circuit and predict the voltage drop and temperature rise caused by quasi-static indentation. The method is modeled by applying the material nonlinearity of each LIB component and considering detailed layers; then, the internal short-circuit caused by mechanical deformation and cathode–anode contact was calculated. The electrochemical model comprising Randles circuits calculates the heat generated due to internal short-circuit. The thermal model calculates the temperature over time by using heat sources from the electrochemical model. At each timestep, we analyze the internal short-circuit, heat generation, and the temperature rise via mechanical-electrochemical-thermal coupled analysis. The predicted values were compared with the experimental results of spherical-punch indentation using three different diameters for a 3.2 Ah pouch cell; the onset of internal short-circuit and peak temperature varied by 3.3% and 3.2%, respectively, between the predicted values and experimental results. Furthermore, the peak temperature decreased with the increasing diameter of the spherical punch; our model accurately predicts the voltage drop caused by internal short-circuits.

Investigation of High-Frequency Fine Structure in the Current Output of Shaped Contact Planar Gunn Diodes

A novel gallium arsenide (GaAs) planar Gunn diode design with shaped anode and cathode contacts using Monte Carlo simulations has been shown to produce significantly higher frequency fine structure components in the output waveform than the natural transit time frequency of the diode. We have investigated devices without a feedback potential and devices with a feedback potential (in the delayed mode) and have shown 350-GHz fine structure frequency components in a device with a nominal transit time frequency of 70 GHz is possible. This is the first observation of such stable repeating high-frequency components in a Gunn diode, giving potential for very high-frequency power generation and other wave-shaping applications.

Cell performance of passive paper-based microfluidic fuel cells with mini-hole array in the anode flow channel

Paper-based microfluidic fuel cells (PMFCs) exploit the capillary flow in paper porous media to enable passive transport of reactants, and also use the co-laminar flow nature to separate the fuel and oxidant, thereby eliminating the conventional proton exchange membrane and micro-pumps. PMFCs have been regarded as promising micro-power sources for next-generation paper-based electrochemical microfluidic assay for biomedical diagnosis. The PMFC performance is usually limited by fuel transport, failing to meet the power requirement. At present, the paper-based microfluidic fuel cells have been reported to improve the performance mainly by changing the operating parameters, the physical parameters of the paper channel and the absorption pad, and the cell structure. However, few studies have been reported to improve the cell performance by enhancing fuel transfer. In this paper, a new anode structure is proposed to enhance fuel transfer. That is, a mini-hole array is constructed in the paper-based channel on the anode to make part of the catalyst layer of the anode contact with the mini-hole array. It was expected that the fluid in the mini-hole array can not only enhance the convective fuel transport, but also improve the diffusive fuel transport due to the direct contact between the fluid in the paper-based flow channel and anode catalyst layer. Performance comparison was firstly conducted between paper-based microfluidic fuel cells with conventional flow channel and mini-hole array in the anode flow channel. Moreover, effects of operation conditions including anode/cathode interspace, electrode length, fuel and electrolyte concentration on the cell performance were investigated and discussed. The experimental results confirmed that the mini-hole array in the anode flow channel can enhance fuel transport and ion conduction. As compared to the PMFC with the conventional flow channel, the PMFC with mini-hole array in the anode flow channel yielded 41.2% higher maximum power density. In addition, the experimental data also indicated that the ion transfer resistance can be reduced by diminishing the anode/cathode interspace, leading to an improved cell performance. No obvious fuel crossover was observed even at the interspace of 1.0 mm, because the flow rate of catholyte was higher than that of the anolyte, impeding the fuel crossover towards the cathode. The maximum power density of the cell increased with the decrease in the electrode length. This was mainly due to electrochemical reaction consumption and slow diffusion on the anode surface, which would reduce the fuel concentration on the anode surface along the flow direction, forming a concentration boundary layer and limiting the cell performance. In addition, upon the increasement of fuel or electrolyte concentration, the cell performance was enhanced at relatively low concentration but then dropped at high concentration. The fuel transfer was enhanced at high concentration and the ion transfer resistance can be reduced by increasing the electrolyte concentration, leading to an improved cell performance. However, the viscosity and density of the fuel and electrolyte increase with the electrolyte concentration, which led to the decrease of the flow rate of the reactants, further resulting in fuel mass transfer limitation and performance reduction. The optimal power density reached 29.7 mW/cm2 by the proposed PMFC at the anode/cathode interspace of 1.0 mm, the electrode length of 5.0 mm, and the fuel and electrolyte concentrations of 2.0 mol/L.

Impact of Anode on Product Formation During the Electrochemical Reduction of Chalcopyrite

A hydrometallurgical process has been demonstrated to electrochemically convert chalcopyrite (CuFeS2) to less refractory mineral phases for subsequent chemical oxidation. The electrochemical reaction mechanisms are not well understood; consequently, researchers have been unable to improve the process. In this study, the bulk and surface phases of the chalcopyrite mineral during the progression of the electrochemical reactions are monitored using x-ray diffraction and x-ray photoelectron spectroscopy, respectively. The results suggest that chalcopyrite reacts at the cathode of the electrochemical reactor to release iron and form an intermediate chalcocite (Cu2S) mineral phase. Allowing Cu2S to contact the anode leads to the formation of covellite (CuS), whereas preventing the mineral from anode contact leads to the formation of cuprite (Cu2O). It was shown that copper ions are more easily extracted from Cu2O than CuS; therefore, it may be desirable to isolate the anode from mineral contact during the electrochemical process.

Development of Very High Luminance p–i–n Junction‐Based Blue Fluorescent Organic Light‐Emitting Diodes

AbstractOrganic light‐emitting diodes (OLEDs) can emit light over much larger areas than their inorganic counterparts, offer mechanical flexibility, and can be readily integrated on various substrates and backplanes. However, the amount of light they emit per unit area is typically lower and the required operating voltage is higher, which can be a limitation for emerging applications of OLEDs, e.g., in outdoor and high‐dynamic‐range displays, biomedical devices, or visible‐light communication. Here, high‐luminance, blue‐emitting (λpeak = 464 nm), fluorescent p–i–n OLEDs are developed by combining three strategies: First, the thickness of the intrinsic layers in the device is decreased to reduce internal voltage loss. Second, different electron‐blocking layer materials are tested to recover efficiency losses resulting from this thickness reduction. Third, the geometry of the anode contact is optimized, which leads to a substantial reduction in the in‐plane resistive voltage losses. The OLEDs retain a maximum external quantum efficiency of 4.4% as expected for an optimized fluorescent device and reach a luminance of 132 000 cd m−2 and an optical power density of 2.4 mW mm−2 at 5 V, a nearly eightfold improvement compared to the original reference device.

Physical-Based Simulation of the GaN-Based Grooved-Anode Planar Gunn Diode.

In this paper, a novel gallium nitride (GaN)-based heterostructure Gunn diode is proposed for the first time to enhance the output characteristics of Gunn oscillation waveforms. A well-designed grooved anode contact is adopted to separate the long-channel diode into two short-channel diodes in parallel. If the grooved anode contact is positioned in the middle of the device, the output power nearly doubles in the grooved-anode diode compared with the single-channel ones, as does the output frequency. Based on the numerical results, the best output characteristics are obtained at the 2.0-µm symmetrical grooved-anode diode, which produces nearly 5.48 mW of power at the fundamental frequency of 172.81 GHz, with 3.13% efficiency of power conversion. If the grooved anode contact is not positioned in the middle of the diode, the harmonic frequency would be enhanced. The GaN heterostructure grooved-anode Gunn diode has been demonstrated to be an excellent solid-state source of terahertz oscillator.

Efficient lateral-structure perovskite single crystal solar cells with high operational stability

The power conversion efficiency of perovskite polycrystalline thin film solar cells has rapidly increased in recent years, while the stability still lags behind due to its low thermal stability as well as the fast ion migration along the massive grain boundaries. Here, stable and efficient lateral-structure perovskite solar cells (PSCs) are achieved based on perovskite single crystals. By optimizing anode contact with a simple surface treatment, the open circuit voltage and fill factor dramatically increase and promote the efficiency of the devices exceeding 11% (0.05 to 1 Sun) compared to that of 5.9% (0.25 Sun) of the best lateral-structure single crystal PSCs previously reported. Devices show excellent operational stability and no degradation observed after 200 h continuous operation at maximum power point under 1 Sun illumination. Devices with scalable architectures are investigated by utilizing interdigital electrodes, which show huge potential to realize low cost and highly efficient perovskite photovoltaic devices.

Uniformizing the electric field distribution and ion migration during zinc plating/stripping via a binary polymer blend artificial interphase

The PAM/PVP interphase prevents direct contact of the metal Zn anode with the aqueous electrolyte and uniformizes electric field distribution and ion migration during zinc plating/stripping, suppressing the zinc dendrite growth and side reactions.