Advanced Electronic Materials最新文献

Based on first-principles calculations and symmetry analysis, we report a magnetization-orientation-controlled topological phase transition and anomalous transport effects in hexagonal MnSb. Owing to its remarkably low magnetic anisotropy energy (0.465 meV), the magnetization direction in MnSb can be readily manipulated by external perturbations. Without spin-orbit coupling (SOC), a symmetry-protected Dirac point (DP) lies 9 meV below the Fermi level. Upon inclusion of SOC, this DP undergoes an evolution as a function of magnetization orientation: it opens a gap at θ = 0° (magnetization along the a-axis) due to the symmetry breaking, and transforms into four Weyl points at θ = 90° (magnetization along the c-axis). These topological transitions are accompanied by significant Berry curvature reconstruction, which profoundly influences the anomalous transport responses. Specifically, the anomalous Hall conductivity increases monotonically from –100.64 Ω⁻¹cm⁻¹ at θ = 0° to a maximum of –754.72 Ω⁻¹cm⁻¹ at θ = 90°, whereas the anomalous Nernst coefficient undergoes a sign reversal, changing from +0.50 Am⁻¹K⁻¹ to –0.09 Am⁻¹K⁻¹ as the magnetization rotates. Our work establishes a design principle for engineering magnetic topological materials, with MnSb serving as a representative example to explore the interplay between magnetic order and topology-driven transport phenomena. These findings bridge magnetism, topology, and transport physics, opening a pathway toward novel spintronic devices through tunable magnetization direction.

As data-intensive applications increasingly strain conventional computing systems, processing-in-memory (PIM) has emerged as a promising paradigm to alleviate the memory wall by minimizing data transfer between memory and processing units. This review presents the recent advances in both stateful and non-stateful logic techniques for PIM, focusing on emerging nonvolatile memory technologies such as resistive random-access memory (RRAM), phase-change memory (PCM), and magnetoresistive random-access memory (MRAM). Both experimentally demonstrated and simulated logic designs are critically examined, highlighting key challenges in reliability and the role of device-level optimization in enabling scalable and commercial viable PIM systems. The review begins with an overview of relevant logic families, memristive device types, and associated reliability metrics. Each logic family is then explored in terms of how it capitalizes on distinct device properties to implement logic techniques. A comparative table of representative device stacks and performance parameters illustrates trade-offs and quality indicators. Through this comprehensive analysis, the development of optimized, robust memristive devices for next-generation PIM applications is supported.

Electrowetting displays (EWDs) are a new generation of electronic paper displays, featuring low power consumption and a wide viewing angle. Owing to their alignment with green environmental protection and energy conservation concepts, the EWDs exhibit vast market potential. However, current EWDs face challenges such as high driving voltages, ink backflow, response speed and aperture ratio which need further improvement. Hence, this paper describes for the first time the preparation of hexagonal-pixel EWDs based on the principle of 2D dense tiling and microfluidics theory at the corner. Compared with square-pixel EWDs, the hexagonal-pixel EWDs reduced the threshold voltage by 42.67% and the voltage required to maintain the maximum aperture ratio by 13.94%, while keeping the maximum aperture ratio unchanged. Moreover, based on ink motion theory in EWDs, a hybrid driving waveform combining exponential and alternating current (AC) is proposed for the prepared hexagonal-pixel EWDs. Compared with traditional direct current (DC) and pulse width modulation (PWM) driving waveforms, this driving waveform reduced the brightness fluctuations from 22.374 and 20.726 to 3.110 in the ink driving stage, and from 4.211 and 25.316 to 1.827 in the stable display stage, respectively.

Suspended indium arsenide (InAs) nanowires offer a unique platform for studying surface-driven transport phenomena due to their high surface-to-volume ratio and the absence of dielectric interfaces. In this work, we investigate the role of surface states in InAs nanowire field-effect transistors. Electrical characterization reveals a high electron mobility of ≈1500 cm²V⁻¹s⁻¹, alongside a subthreshold swing of 1.49 V dec⁻¹, indicating a reduced gate efficiency caused by surface traps. Temperature-dependent analysis yields activation energies of ∼100 meV, confirming the dominant influence of shallow trap states on both threshold voltage and subthreshold slope. Under pulsed optical excitation, the devices exhibit persistent negative photoconductivity and gate-tunable hysteresis. The on/off current ratio exceeds 10⁵ at 200 K. These effects are attributed to a photogating mechanism controlled by the interplay between gate voltage and photoinduced trap occupation. The demonstrated ability to modulate long and short-term memory behavior through optical and electrical stimuli highlights the potential of these nanowire devices for neuromorphic applications.

Magnetoelectric materials are one of the potential candidates that can counter the growing need of low-power memory and spintronic devices due to their ability to electrically control magnetic states. Manipulation of a magnetic state with the sole use of an electric field has faced several challenges like volatility and non-reproducibility. Here, we propose a magnetostrictive FeGa thin film interfaced with a relaxor ferroelectric substrate (PMN-PT) having a [011] surface cut. The polarization rotation is controlled near the coercive electric fields and stabilized at remanence, which generates distinct strained states. This strain transfers to the FeGa layer mechanically, inducing a net rotation of magnetization without the need of any bias magnetic field applicators. Imaging of the magnetic domains reveals spatial and real-time information about its variation and adds insight on the modification of magnetic anisotropy. The newly created magnetic information can be erased by reaching ferroelectric saturation and subsequently regenerated through specific electrical pulses. These results demonstrate the possibility of manipulating the magnetization via controlled polarization rotation, for use in strain-driven magneto-electronics.

Anthracene based fluorescent host materials continue to play a pivotal role in advancing device efficiency and lifetime. Especially when synergized with state-of-the-art narrowband fluorescent emitters. In this context, we developed two anthracene naphthobenzofuran-based host materials, NBFPAn and NBFNAn, through rational molecular engineering. Their planar yet sterically optimized structures effectively suppress intermolecular π–π stacking, minimizing excimer formation, and facilitating efficient singlet energy transfer to the dopant. The doped host films with multi-resonance TADF emitter m-t-DABNA, the host films exhibit PLQYs of 84.2% (NBFPAn) and 93.9% (NBFNAn), along with high horizontal transition dipole orientations (Θ) of 83.8% and 88.2%, respectively. Additionally, both hosts exhibit excellent thermal and morphological stability, with decomposition temperatures (T_d) above 355°C and 381°C for NBFPAn and NBFNAn respectively, supporting reliable vacuum deposition. Devices employing these hosts achieve deep blue emission of λ_em 463 nm, with EQE_max of 10.5% and 8.56% for NBFPAn and NBFNAn, respectively. Notably, the NBFPAn based device exhibits an extended lifetime (LT₉₀) of 45 h at 1000 cd m⁻². This work underscores the critical role of molecular engineering toward simultaneously enhancing device efficiency and operational lifetime through optimizing exciton dynamics, charge transports for next-generation high-performance blue OLEDs.

The non-uniform current distribution arising from either the current crowding effect or the hot spot effect provides a method to tailor the interaction between thermal gradient and electron transport in magnetically ordered systems. Here, we apply the device structural engineering to realize an in-plane inhomogeneous‌ temperature distribution within the conduction channel, and the resulting geometric anomalous Nernst effect (GANE) gives rise to a nonlinear effect whose polarity corresponds to the out-of-plane magnetization of Co/Pt multi-layer thin film, and its resistance is linearly proportional to the applied current. By optimizing the aspect ratio of a convex-shaped device, the effective temperature gradient can reach up to 0.3 K µm⁻¹ along the y-direction, leading to a GANE signal of 28.3 µV. Moreover, we demonstrate electrical write and read operations in the perpendicularly magnetized Co/Pt-based spin–orbit torque device with a simple two-terminal structure. Our results unveil a new pathway to utilize thermoelectric effects for constructing high-density magnetic memories.

The diffusion of carbon interstitial (C_i) mediates the transport of excess carbon atoms and the subsequent interstitial-vacancy recombination that eliminates the main carrier lifetime killers, carbon vacancies, in silicon carbide (SiC). Therefore, it plays a crucial role in material growth, device fabrication, and thermal treatment for improved material performance. In this work, the thermodynamic and kinetic behaviors of C_i diffusion in 4H-SiC are investigated using first-principles calculations. The calculations indicate that near the charge-state transition levels, a migration mechanism emerges in which the charge-state transition occurs prior to C_i migration, which lowers the overall energy barrier. Furthermore, the thermodynamically activated temperature region and kinetic diffusion coefficient are predicted from a theoretical perspective, considering effective potential barriers and entropic effects. Both the activation temperature and diffusion coefficient exhibit strong dependence on the Fermi level and lattice site. Compared to the C_i at the k site, the C_i at the h site exhibits higher diffusivity. Moreover, slight n-type doping enhances the diffusion of C_i at both sites. Overall, the broader annealing window and higher dynamic diffusion coefficients highlight the significant role of C_i in defect healing, offering theoretical insights and essential parameters for optimizing experimental conditions.

Understanding the atomic origin of magnetic anisotropy is of paramount importance for designing advanced magnetic materials for the next generation of magnetic and spintronic technologies. The Ru-substituted La_0.70Sr_0.30MnO₃ (Ru-LSMO) system has recently attracted attention due to its attractive magnetic and magneto-transport properties, where magnetic anisotropy plays a pivotal role. However, the atomic mechanisms governing magnetic anisotropy in this material system remain elusive, hindering technological maturation. Here, a novel cooperative atomic mechanism is identified for emergent tilted magnetic anisotropy (TMA) in Ru-LSMO films. Using element-specific X-ray magnetic dichroism (XMCD), it is uncovered that macroscopic TMA stems from the cooperation of single-ion anisotropy in the Ru ions and antiferromagnetic exchange interaction with the Mn ions. Remarkably, despite the absence of single-ion anisotropy, the Mn ions exhibit robust TMA because of this exchange interaction, transforming the otherwise in-plane magnetic anisotropy in Mn ions of pure LSMO. These phenomena persist to near room temperature, underscoring the technological potential. These findings open a promising route for atomic-scale engineering of magnetic anisotropy, paving the way for the next generation magnetic and spintronic technologies.

Nitrogen dioxide sensors are important for environmental monitoring, and OFETs-based devices feature high sensitivity, low production cost and power consumption. While transient pulsed saturation measurements are the most common approach to measure the sensor response, here we systematically compare it with the periodic transfer curves measurement method in both linear and saturation regimes for C8-BTBT OFETs sensitive to NO₂. We show that the sensitivity strongly depends on the measurement routine, governed by competition for deep trap sites between the electrically injected holes and NO₂-induced doping. The transfer curves method reveals that mobility change dominates in the saturation regime, while threshold voltage shift dominates in the linear regime, confirming deep traps role as key sensing receptor sites. Pulsed measurements, especially in the linear regime, yielded the highest sensitivity (218 ± 18%/ppm) by combining low charge density with low duty cycle kinetics to maximize the initial deep trap availability. DFT calculations support preferential hole transfer from NO₂ to the trap states. Altogether confirming that minimizing trap filling by injected charge (i.e., lower current density operation) enhances OFET sensitivity. This dependence on the measurement routine persists even for OFETs containing metalloporphyrin receptor layers. These findings provide guidelines for optimizing OFET sensor design and operation.