O3-type layered cathodes have attracted extensive attention due to their high reversible capacity and sufficient sodium-ion utilization. However, induced by continuous phase transitions, O3-type cathodes generally suffer from severe structural degradation and performance deterioration during the charge/discharge process. In response to this challenge, the single-crystalline O3/P2 biphasic layered cathodes (O3/P2-NNMO) were realized by a facile solvent-regulated strategy. The characterization results indicated that O3/P2-NNMO cathodes are endowed with the favorable surface chemistry environments contributed by low surface residual-sodium impurities and high Mn4+/Mn3+ proportion. Importantly, P2 phase was inter-grown into O3-type phase to form an interlock structure in a single-crystalline O3/P2-NNMO particle, which relieves the phase transitions to remarkably reduces lattice variation. The stable surface structure and reinforced bulk lattice cooperatively strengthen the cycling stability of cathodes. As expected, O3/P2-NNMO cathodes deliver a high reversible capacity of 117.2 mAh g-1 at 0.1 C (14 mA g-1), and excellent cycling stability with a capacity retention of 75% after 100 cycles at 1 C. Also, the fast Na+ migration pathway provided by P2 phase significantly promotes the Na+ diffusion kinetics and interfacial charge transfer in O3/P2-NNMO cathodes, enabling a superior rate capability. This work provides a new design idea for advanced layered cathodes for sodium-ion batteries.

Lithium-thionyl chloride (Li/SOCl2) batteries offer a high energy density (∼710 Wh kg-1), high voltage plateau (∼3.5 V), and applicability in extreme temperature conditions (-55-150 °C), and their secondary system is considered a promising alternative for next-generation energy storage. However, the current rechargeable Li/SOCl2 batteries exhibit unsatisfactory reversible capacities, especially under low-temperature conditions, where their reversibility drops sharply. This is primarily due to the poor oxidation efficiency of lithium chloride (LiCl) on the carbon surface. In this work, we engineered an activated carbon (AC) host featuring a high specific surface area and abundant oxygen-functional groups to enhance LiCl utilization. The AC particles provide numerous reaction sites through their microporous structure and modulate the interfacial kinetics via their oxygen-functional groups. This dual-functional role facilitates high LiCl oxidation while lowering electrochemical polarization. The Li/SOCl2 batteries utilizing AC hosts (Li/SOCl2@AC) deliver a high reversible capacity of 1500 mAh g-1 with a discharge voltage plateau of ∼3.5 V. Moreover, the Li/SOCl2@AC batteries can be durable for up to 200 cycles at a cycling capacity of 1000 mAh g-1 even under -20 °C conditions. This work provides new insights into designing highly reversible rechargeable Li/SOCl2 batteries with wide temperature adaptability.

Achieving both high carrier mobility and high luminous efficiency in a single material remains a major challenge in the development of high-performance organic light-emitting transistors (OLETs). Traditional high-mobility materials, such as acene derivatives, often suffer from luminescence quenching because of strong molecular aggregation, whereas highly emissive materials typically exhibit poor charge transport performance. In this paper, we propose a molecular design strategy based on planarization engineering to improve the photoelectric properties of nanogrids and investigate the effect of multi-grid structures on the photoelectric properties. A series of benzo [1,2-b:4,5-b′] dithiophene (BDT)-based nanogrid molecules, including BDTGs, BDTGs-D and BDTGs-T, were designed through the incorporation of benzene rings. Theoretical calculations demonstrate that planarization engineering significantly reduces the hole reorganization energy from 0.122 eV to 0.06 eV and enhances hole mobility to as high as 18.134 cm2V−1 s−1 through improved molecular packing. Further analysis indicates that the proposed structure increases the spontaneous emission rate (2.500 × 108 s−1) relative to the internal conversion rate (9.267 × 107 s−1), thereby enhancing the efficiency of radiative recombination. These results demonstrate that the proposed strategy can simultaneously optimize charge transport and luminescence in OLET materials, providing a promising molecular design approach for next-generation optoelectronic devices.

The commercialization of lithium‑sulfur (LiS) batteries is still seriously limited by the shuttle effect of lithium polysulfides (LiPSs). Herein, to impede the shuttle effect and improve the battery performance, carbon-coated manganese selenide composites (MnSe@C-N) were synthesized and applied as a functional intermediate layer in polypropylene (PP) separators for LiS batteries. The impact of selenium vacancy concentration on their electrochemical performance is intensively investigated. The carbon material offers excellent conductivity, while MnSe with abundant selenium vacancies provides synergistic barrier, adsorption, and catalytic effects. The MnSe@C-N-modified separator with high selenium vacancy density exhibits outstanding electrochemical performance. The assembled lithium‑sulfur battery demonstrated an initial discharge capacity of 1432.5 mAh g−1 at 0.1C. After 600 cycles at 2C, the capacity retention rate was approximately 72.3%, with a capacity decay rate of only 0.046% per cycle. This comparative study expands the application of MnSe in energy storage and provides a promising MnSe@C-N matrix material for advanced lithium‑sulfur batteries. It also offers new insights into developing high-performance selenide battery materials through defect engineering design.

The sluggish reduction kinetics of thionyl chloride and the cathode passivation induced by the densification deposition of discharge product LiCl are critical challenges that severely hinder the commercialization of lithium/thionyl chloride (Li/SOCl2) batteries. In this work, a dual-catalyst cobalt tetrapyridine porphyrin (CoTAP) and copper phthalocyanine (CuPc) supported on activated carbon (AC) were proposed to synergically regulate SOCl2 reduction and product deposition. When the CoTAP/CuPc/AC catalyst was synthesized and applied as the cathode of Li/SOCl2 batteries, UV-Vis spectroscopy, crystal field coordination structure analysis, DFT calculations and XPS measurements collectively demonstrated that CoTAP catalyzes SOCl2 reduction through coordination at Co sites and strongly adsorbs Cl−, while CuPc features a weakly coordinated Cu center that facilitates the migration of LiCl products from the cathode surface. This collaborative effect in CoTAP/CuPc/AC cathodes effectively accelerates the reduction kinetics of SOCl2 and promotes the ordered deposition of product LiCl, thereby guaranteeing the continuous and progressive discharge process in Li/SOCl2 batteries. As a result, the CoTAP/CuPc/AC-catalyzed batteries exhibited excellent electrochemical performance with a stable discharge voltage of 3.16 V and high discharge capacity of 15.08 mAh, superior to the counterpart batteries without catalysts. This work provides a design idea for the development of advanced Li/SOCl2 batteries.

Electromagnetic wave absorbers with dynamically tunable absorption bands are highly desirable for adapting to complex and variable electromagnetic environments. Herein, a shape-memory-enabled porous carbon composite is developed by integrating carbon nanotubes (CNTs), melamine foam (MF), and shape memory resin (SMR), in which reversible microstructural reconstruction is exploited to regulate dielectric properties and electromagnetic wave absorption behavior. CNTs uniformly coat the three-dimensional MF skeleton to construct a continuous conductive network, while SMR serves as a thermally responsive component to fix and release compressive deformation without continuous external stress. Upon compression, densification of the CNTs network significantly enhances conductivity and dielectric loss, whereas shape recovery restores a sparse conductive architecture. The CNTs/MF-SMR composite exhibits dynamically tunable electromagnetic wave absorption with reversible switching of absorption bands. At 50% compressive strain, a minimum reflection loss of -70.1 dB is achieved at 10.4 GHz, accompanied by a broad effective absorption bandwidth covering the X-band. The shapememory-driven regulation shows excellent reversibility and structural stability, with recovery ratios exceeding 99% over repeated cycles. This work demonstrates that shape-memory-driven conductive network reconstruction offers an effective and universal strategy for the design of intelligent, adaptive carbon-based electromagnetic wave absorbers.

Raising the cutoff voltage of charging is an economically effective strategy to maximize the reversible capacity of Ni-rich cathodes without changing their compositions. However, the high surface reactivity of Ni-rich cathodes at high voltage would trigger harmful interfacial side reactions between the cathodes and the electrolyte, resulting in structural degradation and performance deterioration. In response to this challenge, surface passivation induced by gradient Ce4+ doping was proposed to strengthen the surface/interfacial stability of Ni-rich cathodes and thereby promote their high-voltage cycling capability. Incorporating Ce4+ ions into the surface lattice of Ni-rich cathodes can not only lower the surface reactivity by diluting surface-active Ni3+ species and reducing surface residual lithium impurities, but also stabilize the surface lattice oxygen by strong Ce-O bonds, thereby inhibiting surface degradation under high-voltage operation. Alternatively, large-radius Ce4+ ions doping expands the interlayer distance along the c -axis to provide a beneficial channel for Li+ diffusion, verified by reaction kinetics results. As expected, Ce-doped Ni-rich cathodes deliver a high reversible capacity of 210.3 mAh g-1, excellent cycling stability with a capacity retention of 83.9% after 100 cycles, and superior rate capability at a high cutoff voltage of 4.6 V. This work provides a design idea for stabilizing the surface/interface of Ni-rich cathodes for high-performance lithium-ion batteries.

Rechargeable lithium/thionyl chloride (Li/SOCl2) batteries garner interest due to their ultra-high energy density (710 Wh kg(-1)) and high output voltage plateau (3.3-3.6 V). However, the large insulated lithium chloride (LiCl) particles on the cathode surface make oxidation difficult and cause cathode blockage, exacerbating the irreversibility and instability of the batteries. Active materials that can both enable SOCl2 reduction and efficiently regulate deposit formation are desired. Herein, Cobalt phthalocyanine (CoPc) is anchored to activated carbon (AC) via Co-O coordination and pi-pi conjugation to prepare nanosized CoPc/AC with highly dispersed active sites. The CoPc/AC catalyst significantly enhances SOCl2 reduction kinetics, enables rapid nucleation of discharge products, and achieves nanosized LiCl particles (<1 mu m) with a porous deposition structure. These nanosized LiCl particles can be easily transformed during charging and enable the cathode to depassivate during discharging, thereby effectively alleviating electrode blockage during cycling to achieve charge/discharge stability. The CoPc/AC catalyzed batteries deliver over 450 cycles and 235 cycles at a reversible capacity of 500 mAh g(-1) and 1000 mAh g(-1), respectively, demonstrating excellent stability. This work offers a novel insight into the structure optimization of the deposition to enhance charge/discharge stability and towards long-life-span rechargeable Li/SOCl2 batteries.

Lithium/thionyl chloride (Li/SOCl2) batteries are considered a promising alternative for next-generation energy storage, offering high energy density and a broad operating temperature range. However, current rechargeable Li/SOCl2 batteries exhibit poor large-current tolerance due to sluggish chloride ion (Cl-) oxidation kinetics. Reported strategies for Cl- oxidation catalysis remain confined to the single catalytic sites, posing a significant challenge to achieve ultra-high current Li/SOCl2 batteries. Herein, the collaborative catalysis of metal-ligand was proposed to accelerate Cl- oxidation kinetics, which was realized by the cobalt phthalocyanine containing pyridyl-nitrogen (CoTAP). The central Co2+ facilitates Cl- capture, while the peripheral pyridine ligand synergistically accepts electrons. This collaboration mediates electron exchange between the electrode and Cl-, enabling a kinetically optimized Cl- oxidation in a rechargeable Li/SOCl2 battery. Consequently, rechargeable Li/SOCl2 batteries catalyzed by CoTAP can durably operate at ultra-high current densities (up to 20 mA cm-2) while maintaining a constant coulombic efficiency (almost 100%) during long-term cycling. Meanwhile, it shows excellent cycling capability under a wide temperature range from -40 degrees C to 50 degrees C. This work proposes a synergistic catalysis mechanism of metal-ligand on Cl- oxidation, which provides a new design concept for rechargeable Li/SOCl2 batteries.

To improve the energy density of single-crystal LiNi0.5Co0.2Mn0.3O2 (NMC523) by increasing the charging cut-off voltage presents a big challenge since the material degrades significantly at high voltage (>4.3V). A simple method to enhance the high-voltage electrochemical properties of single-crystal NMC523 was proposed by introducing a mesoporous TiO2 coating and Ti doping. The specific discharge capacity for the modified NCM523-M-TiO2-0.5 sample achieves 182.81 mAh g(-1) at a 0.1 C rate within the 3.0-4.5 V range. Furthermore, the capacity retention rate was 80.69 % after 200 cycles at a charge/discharge rate of 1 C, significantly higher than that of bare NCM523, which exhibited values of 181.36 mAh g(-1) and 46.40 %. In detail, the mesoporous TiO2 coating shields the cathode from the electrolyte, enhancing the stability at the interface and promoting the movement of lithium ions. Additionally, Ti doping increases lattice spacing and stabilizes the layered structure. This research will inform the design of high-performance cathode materials for Li-ion batteries.

Ni-rich layered cathodes are regarded as the most promising candidates for next-generation power batteries due to their large capacity. However, Ni-rich cathodes are highly sensitive to moisture in air and are prone to triggering surface chemical reactions to generate residual lithium compounds during production and storage, which poses a significant obstacle to their practical application. This paper systematically investigated the critical factors (humidity, temperature, and time) that affect the growth of residual lithium compounds and variations on the surface/interfacial structure, aiming to elucidate the surface/interfacial degradation of Ni-rich cathodes during storage. It was discovered that a surface chemical reaction with moist air induces the active lattice Li+ ions in the subsurface region to gradually segregate into the surface and participate in the formation and continuous growth of amorphous Li2CO3 layers on cathode particles. Synchronously, induced by consumption of lattice Li+ ions, a structural degeneration from the layered to rock-salt phase was found in the near-surface region of Ni-rich cathodes. Consequently, the substantially increased electrode interfacial impedance contributed by the inactive surface/interface phase results in the deterioration of electrochemical performance. This work provides insights into the failure mechanism of Ni-rich cathodes during storage.

In this article, the threshold voltage ( Vth) characteristic of beta -Gallium Oxide ( beta -Ga2O3) based enhancement mode (E-mode) heterojunction gate field effect transistor (FET) is investigated. A self-aligned gate Ga2O3/NiO x heterojunction FET (SHJ-FET) and a conventional gate Ga2O3/NiOx heterojunction FET (CHJ-FET) are fabricated to research the variation of threshold voltage with the length of NiOx . It is found that the Vth of SHJ-FET and CHJ-FET are about 0.6 and 2.4 V, respectively. Moreover, the power figure of merit (PFOM) values of SHJ-FET and CHJ-FET are 0.37 and 0.35 GW/cm(2), respectively. Due to the larger L-NiOx/L-G ratio, the Vth of CHJ-FET is more positive. Then, a physical threshold voltage model of beta -Ga2O3-based heterojunction gate FETs is built, and the Vth is extracted by varying the geometries of the heterojunction gate. Finally, the correctness of the physical model is verified by fitting the threshold voltage of the actual device with the simulation results. Furthermore, the physics mechanism of the influence of the L-NiOx/L-G , as well as the position of NiOx on the off-state electric field distribution of the device, has also been studied.

The dielectric loss of carbon materials is closely related to the microstructure and the degree of crystallization, and the microstructure modulation of electromagnetic wave absorbing carbon materials is the key to enhancing absorption properties. In this work, a porous elastic Co@CNF-PDMS composite was prepared by freeze-drying and confined catalysis. The graphitization degree and conductivity loss of carbon nanofibers (CNFs) were regulated by heat treatment temperature and Co catalyst content. The construction of a heterointerface between Co and C enhances the interfacial polarization loss. The Co@CNF-PDMS composite with 4.5 mm achieves the minimum reflection loss (RLmin) of –81.0 dB at 9.9 GHz and RL no higher than –12.1 dB in the whole of the X-band. After applying a load of up to 40% strain and 100 cycles to Co@CNF-PDMS, the dielectric properties of the composite remain stable. With the increase of compression strain, the distribution density of the absorbent increases, and the CNF sheet layer extrusion contact forms a conductive path, which leads to the conductive loss increase, finally, the absorption band moves to a high frequency. The absorption band can be bi-directionally regulated by loading and strain with good stability, which provides a new strategy for the development of intelligent electromagnetic wave absorbing materials.

This letter reports the fabrication and characterization of beta-Ga2O3 metal/ferroelectric/insulator/semiconductor (MFIS) capacitors employing 3 types of HfO2-ZrO2 superlattice (SL) ferroelectric gate dielectrics: SL5, SL10, and SL15, constructed by alternating 5,10, and 15 ALD cycles of HfO2 and ZrO2, respectively, with conventional Hf0.5Zr0.5O2 (HZO) as a reference. Following rapid thermal annealing (RTA) at 550 degrees C for 30 s, all dielectrics are confirmed to exhibit the orthorhombic (111) phase by grazing-incidence x-ray diffraction (GIXRD). Electrical measurements reveal that the SL5 structure achieves an outstanding reduction in leakage current, decreasing from 0.936 A cm(-2) (HZO) to 0.004 A cm(-2) at 3 V, and exhibits the highest remanent polarization (2P(r) = 29.3 mu C cm(-2)), compared to 27.3 mu C cm(-2) (HZO), 22.4 mu C cm(-2) (SL10), and 17 mu C cm(-2) (SL15). Moreover, the SL5 capacitor demonstrates excellent reliability, maintaining robust endurance up to 1 x 10(11) cycles at room temperature and 1 x 10(10) cycles at 150 degrees C without degradation and stable retention over 1 x 10(4) s. Importantly, interface state analysis reveals that after annealing, SL5 maintains the lowest and most stable interface trap density within the energy range of 0.25-0.45 eV. The trap state density (6.39 x 10(12)-7.11 x 10(12) cm(-2) eV(-1)) is significantly lower than that of HZO in the same energy range. These results highlight the advantages of superlattice-engineered ferroelectric gate dielectrics for achieving high-quality interfaces, low leakage current, and stable ferroelectric performance, providing a promising route toward high-performance, enhancement-mode beta-Ga2O3 MOSFET devices for next-generation power electronics.

Rechargeable lithium/thionyl chloride (Li/SOCl2) batteries are considered promising alternatives to lithium-ion batteries because of their ultrahigh energy density and wide operating temperature range. However, current rechargeable Li/SOCl2 batteries exhibit unsatisfactory rate performance that originates from the poor reversibility of SOCl2 and is dominated by the difficulty in oxidizing the discharge product lithium chloride (LiCl). In response to this issue, cobalt phthalocyanine (CoPc) is employed as a cathode catalyst to boost the oxidation kinetics of LiCl products and thus improve the reversibility of SOCl2 in rechargeable Li/SOCl2 batteries. The CoPc catalyst in the Li/SOCl2 batteries is found to not only promote the discharge reduction of SOCl2 but also remarkably accelerate the reversible charge transformation of LiCl products by lowering the chloride ions oxidation barrier. The CoPc-catalyzed Li/SOCl2 batteries deliver a high specific capacity of 800 mAh g-1 at a current density of 500 mA g-1, with a stable voltage plateau of 3.5 V over 200 cycles. Even at the ultrahigh current density of 5 mA cm-2, these batteries can still provide a reversible capacity of 1 mAh cm-2 over 250 cycles, demonstrating excellent rate performance.

Thermally activated delayed fluorescence (TADF)-sensitized host-guest systems (wide-bandgap host: 25 % TADF sensitizer: 5 % emitter) are widely used to enhance OLED efficiency, yet their microscopic mechanisms remain unclear. Using magneto-electroluminescence (MEL) as a fingerprint technique, we reveal dynamic conversions between reverse intersystem crossing (RISC) and intersystem crossing (ISC) in CzDBA-sensitized DCJTB-doped devices (mCP:25 %CzDBA:5 %DCJTB). Current-dependent MEL curves at 300 K exhibit RISC -> ISC -> RISC transitions as current increases from 1 to 200 mu A, contrasting with pure ISC (mCP:25 %CzDBA) and persistent RISC (mCP:5 %DCJTB) behaviors in control devices. Similarly, temperature-dependent MEL at low currents (1-3 mu A) shows RISC -> ISC -> RISC transitions when cooling from 300 to 20 K. These phenomena arise from competing processes: DCJTB polaron pair (PP) state RISC via direct charge trapping, CzDBA charge transfer (CT) state RISC, and cascaded energy transfer (mCP -> CzDBA -> DCJTB via Forster/Dexter mechanisms). At low currents and temperatures, DCJTB PP-RISC dominates, while CzDBA CT-RISC prevails at high currents and 300 K. Increasing CzDBA concentration enhances mCP PP-ISC through strengthened Dexter energy transfer from mCP triplet excitons to CzDBA triplet CT states, concurrently improving current efficiency. Conversely, higher DCJTB concentrations weaken its PP-RISC due to state quenching. This work elucidates the interplay between PP, CT, and exciton states in TADF-sensitized systems, providing critical insights for designing efficient red OLEDs through rational manipulation of energy transfer pathways and state dynamics.

Manganese-based Prussian blue analogues (Mn-PBA) have garnered significant attention due to their exceptionally high specific capacity in aqueous sodium-ion batteries (ASIBs). However, the dissolution of Mn2+ ions during the charge/discharge process leads to structural degradation, adversely affecting cycle life and limiting practical applications. In this work, a high-entropy strategy is employed to overcome this limitation. The resulting high-entropy Mn-PBA (HE-Mn-PBA), synthesized via a simple co-precipitation method, benefits from entropy stabilization and synergistic effects among multiple metal components, enabling excellent structural integrity during prolonged cycling. As a cathode material, HE-Mn-PBA achieves nearly 100 % capacity retention (116.07 mAh g-1) after 200 cycles at 1 A g-1, along with stable performance over 10,000 cycles. In situ Raman spectroscopy confirms the formation of enhanced and reversible redox-active centers, while kinetic analyses reveal significantly improved Na+ diffusion kinetics. Furthermore, a full cell assembled with a polyimide anode delivers a high energy density of 56.11 Wh kg-1. This high-entropy engineering approach offers a promising pathway to address the stability challenges of Mn-based materials in ASIBs.

Charge balances can influence the emission efficiency of exciplex-based organic light-emitting diodes (OLEDs), but so far, the physical mechanism behind this phenomenon is not fully understood. Here, organic magnetic field effects (OMFEs) including magneto-conductance (MC), magneto-electroluminescence (MEL), and magneto-efficiency (M eta) are used as fingerprint probing tools to study physical mechanism of influence of charge balance on the emission efficiency of exciplex-based OLEDs. Specifically, low- and high-field effects of MC traces [MCL (|B| <= 10 mT) and MCH (10 < |B| <= 300 mT)] from the unbalanced device are separately attributed to the magnetic field (B)-mediated intersystem crossing (ISC) process and the B-mediated triplet-charge annihilation (TCA) process between triplet exciplex states and excessive charge carriers, whereas those from the balanced device are respectively attributed to the B-mediated reverse intersystem crossing (RISC) process and the balanced carrier injection. As the injection current decreases from 200 to 25 mu A, low-field effects of MEL traces (MELL) form the unbalanced device always reflect the B-mediated ISC process, but those from the balanced device exhibit a conversion from ISC process to RISC process. Furthermore, although low-field effects of M eta traces (M eta(L)) from unbalanced device and balanced device are attributed to the B-mediated ISC process, M eta(L) value in the balanced device is approximately one-fourth of that in the unbalanced device. These different MC, MEL, and M eta traces reveal that the balanced carrier injection can increase the number of triplet exciplex states via weakening the TCA process, which leads to the enhanced RISC process. Because RISC can convert dark triplet exciplex states into bright singlet exciplex states, the emission efficiency of the balanced device is higher than that of the unbalanced one. Obviously, in this work OMFEs are used to provide a new physical mechanism for charge balance that influences the emission efficiency of exciplex-based OLEDs.

Half-band-gap turn-on characteristic is a unique photoelectric property of organic light-emitting diodes (OLEDs), and has advantage in the development of low driving voltage devices. But the physical mechanism that the electron injection layer (EIL) affects the half-band-gap turn-on characteristic has not been reported. In this work, the change from half-band-gap turn-on electroluminescence (EL) to sub-band-gap turn-on EL to normal turn-on EL is observed by regulating the electron mobility of EIL in Rubrene/C-60 based devices. Three sets of devices are fabricated by using BCP (similar to 10(-3) cm(2)/(V center dot s), Dev. 1), Bphen (similar to 10(-4) cm(2)/(V center dot s), Dev. 2) and TPBi (similar to 10(-5) cm(2)/(V center dot s), Dev. 3) as EIL materials. By measuring the I-B-V curves of devices at room temperature, it is found that the turn-on voltages of devices obviously increase by an order of magnitude with electron mobility of EIL decreasing. Specifically, the turn-on voltage of Dev. 1, Dev. 2, and Dev. 3 exhibit the physical phenomena of half-band-gap turn-on (1.1 V), sub-band-gap turn-on (2.1 V) and normal turn-on (4.1 V) properties, respectively. The magneto-electroluminescence (MEL) results show that the half-band-gap turn-on characteristic of high EIL electron mobility (Dev. 1) is attributed to the triplet-triplet annihilation (TTA, T-1,T-Rb + T(1,Rb)b -> S-1,S-Rb + S-0) process which can effectively reduce the turn-on voltage. However, the half-band-gap turn- on characteristic is not observed in the devices (Dev. 2 and Dev. 3) with low carrier mobility, which can be reasonably explained by a higher voltage that is applied to the EIL with low electron mobility in order to inject more electrons. The higher voltage offsets the reduced turn-on voltage of the TTA process, resulting in Dev. 2 and Dev. 3 with sub-band-gap turn-on and normal turn-on, respectively. In addition, although the TTA process is observed in all three devices, the TTA process is stronger and the EL is higher in Dev. 1 with high EIL electron mobility. This is because a large number of triplet Rubrene/C-60 exciplex states (EX3) are formed at the Rubrene/C-60 interface, enhancing the Dexter energy transfer (DET, EX3 -> T-1,T-Rb) process from EX3 to triplet exciton of Rubrene (T-1,T-Rb). That is, Dev. 1 exhibits stronger TTA process and higher EL due to the presence of a large number of T-1,T-Rb excitons formed by DET process than Dev. 2 and Dev. 3. Furthermore, by measuring the I-V curves of devices at low temperature, it is found that the reduced carrier mobility caused by lowering operational temperature increases the turn-on voltages of these three devices. The significantly different increases in the turn-on voltages of Dev. 1-3 at the same low temperature are due to the different influences of temperature on the electron mobility of EIL. The tradeoff between the decrease of carrier mobility and the extension of exciton lifetime makes the MEL curves present different temperature-dependent behaviors. This work further deepens the understanding of the influence of EIL electron mobility on the turn-on voltage and the related physical microscopic mechanism in Rubrene/C-60 devices.

Ni-rich layered cathodes are deemed as a potential candidate for high-energy-density lithium-ion batteries, but their high sensitivity to air during storage and poor thermal stability are a vital challenge for large-scale applications. In this paper, distinguished from the conventional surface modification and ion doping, an effective solid-solution strategy was proposed to strengthen the surface and structural stability of Ni-rich layered cathodes by introducing Li2MnO3. The structural analysis results indicate that the formation of Li2CO3 inert layers on Ni-rich layered cathodes during storage in air is responsible for the increased electrode interfacial impedance, thereby leading to the severe deterioration of electrochemical performance. The introduction of Li2MnO3 can reduce the surface reactivity of Ni-rich cathode materials, playing a certain suppression effect on the formation of surface Li2CO3 layer and the deterioration of electrochemical performances. Additionally, the thermal analysis results show that the heat release of Ni-rich cathodes strongly depends on the charge of states, and Li2MnO3 can suppress oxygen release and significantly enhance the thermal stability of Ni-rich layered cathodes. This work provides a method to improving the storage performance and thermal stability of Ni-rich cathode materials.