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Magnetic skyrmioniums—with a composite structure comprising two skyrmions with opposite topological charges, exhibit unique dynamic behaviors that are crucial for technological advancements and have application potential for high-density and nonvolatile memory. This study explores the impact of periodic perpendicular magnetic anisotropy (PMA) and damping gradients on skyrmioniums. Utilizing the object oriented micromagnetic framework for detailed simulations, the effective control and enhancement of the skyrmionium stability and mobility through the periodic modulation of PMA and damping gradients is demonstrated. The results demonstrate the dynamic behavior and stability control of skyrmioniums in periodic PMA/damping gradient nanowires. Moreover, the critical influence of the periodic gradient on the skyrmionium motion and stability is highlighted. The results present new avenues for developing advanced memory technologies, leveraging skyrmionium's unique nonlinear behaviors to improve the device performance and reliability. [ABSTRACT FROM AUTHOR]

While magnetoresistive random-access memory (MRAM) stands out as a leading candidate for embedded nonvolatile memory and last-level cache applications, its endurance is compromised by substantial self-heating due to the high programming current density. The effect of self-heating on the endurance of the magnetic tunnel junction (MTJ) has primarily been studied in spin-transfer torque (STT)-MRAM. Here, we analyze the transient temperature response of two-terminal spin–orbit torque (SOT)-MRAM with a 1 ns switching current pulse using electro-thermal simulations. We estimate a peak temperature range of 350–450 °C in 40 nm diameter MTJs, underscoring the critical need for thermal management to improve endurance. We suggest several thermal engineering strategies to reduce the peak temperature by up to 120 °C in such devices, which could improve their endurance by at least a factor of 1000× at 0.75 V operating voltage. These results suggest that two-terminal SOT-MRAM could significantly outperform conventional STT-MRAM in terms of endurance, substantially benefiting from thermal engineering. These insights are pivotal for thermal optimization strategies in the development of MRAM technologies. [ABSTRACT FROM AUTHOR]

Nonvolatile memory using intersubband transitions and quantum-well electron accumulation in GaN/AlN resonant tunneling diodes (RTDs) is a promising candidate for high-speed nonvolatile memory operating on a picosecond timescale. This memory has been fabricated on sapphire(0001) substrates to date because of the high affinity between the nitride materials and the substrate. However, the fabrication of this memory on Si(111) substrates is attractive to realize hybrid integration with Si devices and nonvolatile memory and three-dimensional integration such as chip-on-wafer and wafer-on-wafer. In this study, GaN/AlN RTDs are fabricated on a Si(111) substrate using metal-organic vapor phase epitaxy. The large strain caused by the differences in the thermal expansion coefficients and lattice constants between the Si(111) substrate and nitride materials are suppressed by a growth technique based on the insertion of low-temperature-grown AlGaN and thin AlN layers. The GaN/AlN RTDs fabricated on Si(111) substrates show clear GaN/AlN heterointerfaces and a high ON/OFF ratio of >220, which are equivalent to those for devices fabricated on sapphire(0001) substrates. However, the nonvolatile memory characteristics fluctuate by repeated write/erase memory operations. Evaluation of the ON/OFF switching time and endurance characteristics indicates that the instability of the nonvolatile memory characteristics is caused by electron leakage through deep levels in the quantum-well structure. Possible methods for suppressing this are discussed with an aim of realizing high-speed and high-endurance nonvolatile memory. [ABSTRACT FROM AUTHOR]

Ferroelectric tunnel junctions (FTJs) utilizing hafnium zirconium oxide (HZO) have attracted interest as non-volatile memory for microelectronics due to ease of integration into back-end-of-line (BEOL) complementary metal oxide semiconductor fabrication. This work examines asymmetric electrode NbN/HZO/Nb devices with 7 nm thick HZO as FTJs in a memory structure, with an output resistance that can be controlled by read and write voltages. The individual FTJs are measured to have a tunneling electroresistance of 10 during the read state without significant filament conduction formation and reasonable ferroelectric performance. Endurance and remanent polarizations of up to 105 cycles and 20 μC/cm2, respectively, are measured and are shown to be dependent on the cycling voltage. Electrical measurements demonstrate how magnitude of the write pulse can modulate the high state resistance and the read pulse influences both resistance values as well as separation of resistance states. Then, by using two opposite switching FTJ devices in series, a programmable nonvolatile resistor divider is demonstrated. Measurements of these two FTJ unit memory cells show wide applicability to a BEOL microfabrication process for a re-readable, rewritable, and nonvolatile memory cell. [ABSTRACT FROM AUTHOR]

Due to the growing demand for miniaturization and energy efficiency in modern electronic devices, there is a renewed interest for optoelectronic memories and sensors based on 2D materials. In particular, the molybdenum ditelluride (MoTe 2) is one of the most promising materials for applications in nonvolatile phase-change memory devices, as its properties can be controlled by visible-light illumination. Among the several ways to synthesize MoTe 2 , the molybdenum oxide tellurization through isothermal close space sublimation (CSS) annealing in gas atmosphere is a simple and low-cost effective method for large-scale production of devices based on this layered material. Therefore, the understanding of the physical properties of MoTe 2 thin films produced by this technique is crucial for future applications. Surprisingly, our results indicate that there is a photoinduced growth of the crystalline phase of tellurium on the 1T ′ -MoTe 2 matrix even when the power density of the laser is low. From Raman spectroscopy investigations, we were able to show that nanometer-sized tellurium crystallites work as seed sites for the photocrystallization of tellurium. By assuming that the overall crystallization process is described by a kinetic approach that is based on the Kolmogorov–Johnson–Mehl–Avrami theory, our results indicate that the process is governed by an anisotropic organization of the tellurium atoms in helical structures during the crystal growth. [ABSTRACT FROM AUTHOR]

The ferroelectric tunnel junction (FTJ), which possesses a simple structure, low power consumption, high operation speed, and nondestructive reading, has attracted great attention for the application of next-generation nonvolatile memory. The complementary metal–oxide–semiconductor-compatible hafnium oxide (HfO2) ferroelectric thin film found in the recent decade is promising for the scalability and industrialization of FTJs. However, the electric performance, such as the tunneling electroresistance (TER) effect, of the current HfO2-based FTJs is not very satisfactory. In this work, we propose a type of high-performance HfO2-based FTJ by utilizing a ferroelectric/dielectric composite barrier strategy. Using density functional theory calculations, we study the electronic and transport properties of the designed Ni/HfO2/MgS/Ni (001) FTJ and demonstrate that the introduction of an ultra-thin non-polar MgS layer facilitates the ferroelectric control of effective potential barrier thickness and leads to a significant TER effect. The OFF/ON resistance ratio of the designed FTJ is found to exceed 4 × 103 based on the transmission calculation. Such an enhanced performance is driven by the resonant tunneling effect of the ON state, which significantly increases transmission across the FTJ when the ferroelectric polarization of HfO2 is pointing to the non-polar layer due to the aroused electron accumulation at the HfO2/MgS interface. Our results provide significant insight for the understanding and development of the FTJs based on the HfO2 ferroelectric/non-polar composite barrier. [ABSTRACT FROM AUTHOR]

Magnetization reversal in a synthetic antiferromagnetically coupled composite of perpendicularly magnetized nanomagnets is theoretically explored based on the macrospin model. The analytical expressions of magnetization reversal are derived. The analytical results are confirmed by the results of the Landau–Lifshitz–Gilbert simulation. Furthermore, we find that a critical antiferromagnetic coupling constant exists at which the dynamics of magnetization reversal changes, and we obtain its analytical expression. This report provides a fundamental analysis insight into antiferromagnetic spintronic phenomena suitable for applications in ultra-high speed devices and nonvolatile memory technologies, for example, state-of-the-art voltage-controlled magnetoresistive random access memory. [ABSTRACT FROM AUTHOR]

There is a growing interest in mixing spintronics and superconductivity to develop original energy-efficient nonvolatile memory and logic devices. Research works conducted so far have mostly focused on superconductor with critical temperature Tc lower than 10 K. Here, we report on the growth and characterization of MgB2/Ni80Fe20 and MgB2/Co bilayers, where Tc of the MgB2 layer is of the order of 30 K. Ferromagnetic resonance was undertaken to analyze the spin pumping into MgB2. The larger magnetization at saturation in Co, as compared to Ni80Fe20, induces a smaller spin pumping contribution to the damping when MgB2 is normal. A spin pumping reduction was observed for both bilayers when MgB2 becomes superconductor and is attributed to the opening of the superconducting gap. The present results show that MgB2 thin films could be suitable to implement superconducting spintronic at 30 K, which is not only relevant for future technological development but also relaxes experimental constraints related to low-temperature investigations. [ABSTRACT FROM AUTHOR]

Ferroelectric tunnel junctions (FTJs) based on epitaxial complex oxide heterostructures are promising building blocks for developing low power nanoelectronics and neuromorphic computing. FTJs consisting of correlated oxide electrodes have distinct advantages in size scaling but only yield moderate electroresistance (ER) at room temperature due to the challenge in imposing asymmetric interfacial screening and large modulation of the tunneling potential profile. Here, we achieve large ER in all-oxide FTJs by paring a correlated metal with a narrow bandgap Mott insulator as electrodes. We fabricate epitaxial FTJs composed of 2.8 and 4 nm PbZr0.2Ti0.8O3 tunnel barriers sandwiched between correlated oxides LaNiO3 and Sr3Ir2O7 electrodes. An ER of 6500% has been observed at room temperature, which increases to over 105% at 100 K. The high ER can be attributed to ferroelectric polarization induced metal–insulator transition in interfacial Sr3Ir2O7, which enhances the potential asymmetry for the tunnel barrier. The temperature dependence of tunneling current shows that direct tunneling dominates in the on state, while the off-state conduction transitions from thermally activated behavior at high temperatures to Glazman–Matveev defect-mediated inelastic tunneling at low temperatures. Our study provides a viable material strategy for designing all-oxide FTJs with high ER, facilitating their implementation in nonvolatile memories and energy-efficient computing devices. [ABSTRACT FROM AUTHOR]

With the outstanding growth of Internet of Things (IoT) devices, security and power efficiency of integrated circuits can no longer be overlooked. Current approved standards for cryptographic algorithms are not suitable for constrained environments. In this context, the National Institute of Standards and Technology (NIST) started a lightweight cryptography (LWC) competition to develop new algorithm standards that can be fit into small devices. In 2023, NIST has decided to standardize the Ascon family for LWC. This algorithm has been designed to be more resilient to side-channel and fault-based analysis. Nonetheless, hardware implementations of Ascon have been broken by multiple statistical fault analysis and power analysis. These attacks have underlined the necessity to develop adapted countermeasures to side-channel and perturbation-based attacks. However, existing countermeasures are power and area consuming. In this article, we propose a new countermeasure for the Ascon cipher that does not significantly increase the area and power consumption. Our architecture relies on the nonvolatile feature of the Magnetic Tunnel Junction (MTJ) that is the single element of the emerging Magnetic Random Access Memories (MRAM). The proposed circuit removes the bias exploited by statistical attacks. In addition, we have duplicated and complemented the permutation of Ascon to enhance the power analysis robustness of the circuit. Besides the security aspect, our circuit can save current manipulated data, ensuring energy saving from 11% to 32.5% in case of power failure. The area overhead, compared to an unprotected circuit, is × 2.43 . [ABSTRACT FROM AUTHOR]

Quality of service (QoS) has evolved to ensure performance across various computing environments, focusing on data bandwidth, response time, throughput, and stability. Traditional QoS schemes primarily target DRAM-based homogeneous memory systems, exposing limitations when applied to diverse memory configurations. Moreover, the emergence of nonvolatile memories (NVMs) has made achieving QoS even more challenging due to their differing characteristics. While QoS schemes have been proposed for DRAM-based memory systems or hybrid memory systems combining DRAM and a single NVM type, there is a lack of research on QoS techniques for memory systems that incorporate multiple types of NVM simultaneously. Ensuring QoS in these heterogeneous memory environments is challenging due to significant differences in memory characteristics. In this paper, we propose a novel technique, dynamic affinity-based resource pairing (DARP), designed to enhance QoS in multicore heterogeneous memory systems. The proposed approach dynamically monitors the memory access patterns of applications and leverages the specific read/write characteristics of NVM devices. Detailed information from monitoring is used to optimally allocate memory data to the most suitable memory devices, ensuring stable memory response times and mitigating bottlenecks. Extensive experiments validate the efficiency and scalability of DARP across various workloads and heterogeneous memory configurations, including memory systems with multiple types of NVM. The results show that our technique significantly outperforms state-of-the-art QoS methods in terms of memory response time consistency and overall QoS in heterogeneous memory environments. DARP achieved a memory response time variability of 74.4% in six different memory configurations compared to the baseline on average, demonstrating its high scalability and effectiveness in enhancing QoS across various heterogeneous memory systems. [ABSTRACT FROM AUTHOR]

The solid-electrolyte-based memristors have attracted tremendous attention for the next-generation nonvolatile memory for both logic and neuromorphic applications. However, they encounter variability performance challenges which originated from the random ionic transport and conductive filaments formation. Evidently, the electrochemical metallized mechanism associated with ion transport has been elucidated. Nonetheless, the failure mechanism caused by ion transport during cycles is rarely reported. Hereafter, the five stages of failure in the Ag/Ag10Ge15Te75/W memristor are elucidated through ex-situ current-voltage measurements combined with in-situ transmission electron microscopy characteristics. Our investigation reveals that the migration and enrichment of Ag ions result in the precipitation of Ag2Te. The formation of Ag2Te hinders the device's ability to maintain its bipolar characteristics and also decreases the resistance value of the high resistance state, thereby reducing the device's switching ratio. The promising results provide important guidance for the future design of structures and the manipulation of ion transport for high-performance memristors. [ABSTRACT FROM AUTHOR]

The pursuit of advanced brain‐inspired electronic devices and memory technologies has led to explore novel materials by processing multimodal and multilevel tailored conductive properties as the next generation of semiconductor platforms, due to von Neumann architecture limits. Among such materials, antimony sulfide (Sb2S3) thin films exhibit outstanding optical and electronic properties, and therefore, they are ideal for applications such as thin‐film solar cells and nonvolatile memory systems. This study investigates the conduction modulation and memory functionalities of Sb2S3 thin films deposited via the vapor transport deposition technique. Experimental results indicate that the Ag/Sb2S3/Pt device possesses properties suitable for memory applications, including low operational voltages, robust endurance, and reliable switching behavior. Further, the reproducibility and stability of these properties across different device batches validate the reliability of these devices for practical implementation. Moreover, Sb2S3‐based memristors exhibit artificial neuroplasticity with prolonged stability, promising considerable advancements in neuromorphic computing. Leveraging the photosensitivity of Sb2S3 enables the Ag/Sb2S3/Pt device to exhibit significant low operating potential and conductivity modulation under optical stimulation for memory applications. This research highlights the potential applications of Sb2S3 in future memory devices and optoelectronics and in shaping electronics with versatility. [ABSTRACT FROM AUTHOR]

Organic field-effect transistors (OFETs), based on poly(3-hexylthiophene) (P3HT) enriched by indium-doped zinc oxide (IZO) nanoparticles as an active layer, were successfully prepared by the spin-coating method. We report a significant impact of IZO nanoparticles on the P3HT carrier mobility, which can be controlled by IZO-level loading. The X-ray diffraction and the UV–visible analysis conducted on P3HT/IZO nanocomposite thin films showed an enhancement of the conjugated chain length. Moreover, the improvement of the P3HT properties resulted in an increase in the polymer crystallinity and a reduction of the trap density. A particular result was illustrated corresponding to the enhancement of the carrier mobility and ION/IOFF ratio in the devices based on hybrid nanocomposite. The significant hysteresis observed in this device, which depends on IZO content and illumination under ambient conditions and renders these OFETs promising for various optoelectronic and nonvolatile memory applications. [ABSTRACT FROM AUTHOR]

3D neuromorphic hardware system is first demonstrated in neuromorphic application as on‐chip level by integrating array devices with CMOS circuits after wafer bonding (WB) and interconnection process. The memory window of synaptic device is degraded after WB and 3 Dimesional (3D) integration due to process defects and thermal stress. To address this degradation, Ag diffusion in materials of Ta2O5 and HfO2 is studied in a volatile memristor, furthermore, the interconnection and gate metal Ru are investigated to reduce defective traps of gate interface in non‐volatile memory devices. As a result, a memory window is improved over 106 in both types of devices. Improved and 3D integrated 12 × 14 array devices are identified in the synaptic characteristics according to the change of the synaptic weight from the interconnected Test Element Group (TEG) of the Complementary Metal Oxide Semiconductor (CMOS) circuits. The trained array devices present recognizable image of letters, achieving an accuracy rate of 92% when utilizing a convolutional neural network, comparing the normalized accuracy of 93% achieved by an ideal synapse device. This study proposes to modulate the memory windows up to 106 in an integrated hardware‐based neural system, considering the possibility of device degradation in both volatile and non‐volatile memory devices demonstrated by the hardware neural system. [ABSTRACT FROM AUTHOR]

In two-dimensional valleytronics, the controllability of anomalous valley Hall effect is the key to its practical application. However, most of the previously proposed control methods are volatile or irreversible. Here, using first principles calculations, we demonstrate that the GdF2/Sc2CO2 multiferroic heterojunction can exhibit nonvolatile switching of its electronic band structures. Interestingly, the polarization switching of the ferroelectric monolayer induces movement in the valley polarization band of GdF2, enabling manipulation of the valley Hall effect. This allows the memory state encoded in the ferroelectric monolayer to be read out via the anomalous valley Hall signal of the heterostructures. The switchable anomalous valley Hall effect can also be achieved by applying biaxial strain in the GdF2/Sc2CO2 multiferroic heterojunction. By harnessing this intriguing anomalous valley Hall effect switching characteristic, we develop a nonvolatile valleytronics memory device. This work provides a way to achieve nonvolatile control in valleytronics and promotes the design of memory devices. [ABSTRACT FROM AUTHOR]

Ultrathin ferroelectric tunnel junctions (FTJs) hold considerable promise for next‐generation, high‐speed, low‐power, and high‐density nonvolatile memory applications. Achieving a substantial tunneling electro‐resistance (TER) remains a challenge as the ferroelectric layer is thinned to nanoscale dimensions, often resulting in a diminished or lost polarization. An innovative interface barrier gain mechanism is introduced, employing interface electronic state modulation to precisely control the size of an additional interface barrier. This strategy lessens the dependency of the tunneling barrier on ferroelectric polarization strength, facilitating a remarkable TER even at ferroelectric thicknesses as minimal as ≈1 nm. The focus is on composite FTJs using In2Se3/MTe2 (M = Mo, W), where the inclusion of an MTe2 monolayer disrupts the asymmetric electrode configuration. The weak ferroelectric polarization reversal of the In2Se3 monolayer effectively modulates the electronic state coupling at the In2Se3/MTe2 interface. This modulation leads to variations in the width and height of the Schottky barrier at the heterojunction‐electrode interface corresponding with the ferroelectric polarization reversal, establishing a beneficial Ohmic contact in the “on” state and resulting in an exponential TER increase up to 5.4 × 106%. This work introduces a universal mechanism to overcome the thickness limitations traditionally associated with enhancing TER, marking a significant advancement in the development of ultrathin ferroelectric nonvolatile devices. [ABSTRACT FROM AUTHOR]

Ferroelectric tunnel junctions (FTJs) have gained substantial attention as emerging electronic devices such as nonvolatile memory and artificial synapse, owing to their low power consumption and nonvolatile properties. In this work, a 2D semiconductor (2DS)/α‐In2Se3/metal FTJ structure is proposed that combines a semiconductor ferroelectric material and a semiconducting electrode. The incorporation of 2DS not only enhances the barrier height modulation but also provides an effective approach to mitigate the thermionic current leakage. Notably, the proposed MoS2/α‐In2Se3/Ti FTJs exhibit both room‐temperature negative differential resistance (NDR) effect and high tunnel electroresistance (TER) exceeding 104 simultaneously. Furthermore, the versatility of this structure extends to several 2DS (including MoS2, PdSe2, and SnSe2) and graphene electrodes to rationalize both tunneling and thermionic current transport mechanisms. The proposed 2DS/α‐In2Se3/metal FTJs present great superiority over existing structures in terms of robustness, temperature independence, high TER, and versatility for various potential application scenarios. [ABSTRACT FROM AUTHOR]

Ferroelectric HfO2-based thin films have attracted increasing interest due to their potential applications in nonvolatile memory areas. However, their unique properties, such as imprint, lead to serious reliability issues. In this study, the origin of imprint behavior is investigated by using TiN/Hf0.5Zr0.5O2 (10 nm)/TiN MFM capacitors. By modulating the internal electric field during imprint, we discover that charge injection/de-trapping in metal–ferroelectric interfaces plays an essential role in imprint behavior rather than charge movement inside the FE layer. The asymmetric shift of the coercive field is also discussed, which is attributed to nonlinear interaction between polarization's bound charges and the electrode's screening charges. This suggests that controlling interface quality should effectively suppress imprint in HfO2-based thin films. [ABSTRACT FROM AUTHOR]

Low‐dimensional ferroelectricity is long sought for post‐Moore nanoscale nonvolatile memory. Although a series of 2D ferroelectrics (FEs) have been experimentally confirmed in recent years, the investigations on 1D FEs are still rare. Stimulated by the experimental synthesis of single‐walled carbon/boron nitride nanotubes endohedrally doped by metal halides, our first‐principles calculations show that they can be the candidates for 1D FEs with switchable polarizations vertical to the tube axis as the inner metal halides form into polar zigzag chains. The polarization can be reversed via the migration of metal ions inside the wall, crossing a small barrier around several meV. Similar 1D vertical ferroelectricity in ternary boron carbonitride hybrid nanotubes that have already been synthesized is also predicted. In comparison, herein, polarization is switched by rolling the whole nanotube, which can be realized by applying just a local electric field induced by a tip due to its structural rigidity, which is long sought but remains challenging in current explorations on either conventional or low‐dimensional FEs. [ABSTRACT FROM AUTHOR]

Resistive switching memory devices based on organic materials are intriguing. These devices are biodegradable and nontoxic to living organisms. In this work, using euphorbia cotinifolia plant extract was investigated for its applicability as an active layer of a resistive switching memory device consisting of silver top electrode and indium-doped tin oxide bottom electrode. This study selected Euphorbia cotinifolia because it is a common, prolific and simple-to-grow plant in many South African homes. When the euphorbia cotinifolia plant is broken, an extract resembling milk is emitted. This extract was collected directly onto the bottom electrode, which was then dried at ambient temperature. For top electrode, silver paste was applied. The entire fabrication process was devoid of heat and electricity. The fabricated device showed impressive properties such as memory hysteresis with ON/OFF = 5 , endurance of over 3 2 write/erase cycles, and an impressive retention of ≥ 1 0 3   s. Therefore, this system may be a candidate for a nonvolatile and disposable memory device. [ABSTRACT FROM AUTHOR]

p‐type 2D ferroelectric semiconductors (2D FeSs) play an increasingly essential role in the advanced nonvolatile and morphotropic beyond‐Moore electronic devices with high performance and low power consumption. But reliable p‐type 2D FeS with holes as majority carriers are still scarce. Herein, the first experimental realization of room‐temperature ferroelectricity in van der Waals layered β‐In1.75Sb0.25Se3 down to few layer is reported. The origin of ferroelectricity in β‐In1.75Sb0.25Se3 comes from aliovalent elemental substitution, antimony substituting to the indium sites (SbIn), changing the local environment of the central‐layer Se atoms. Thanks to the intrinsic ferroelectric and semiconducting natures, FeS field‐effect transistor (FeSFET) devices based on β‐In1.75Sb0.25Se3 exhibit reconfigurable, multilevel nonvolatile memory (NVM) states, which can be successively modulated by gate voltage stimuli. Furthermore, the inherent operation mechanism, due to the switchable polarization, indicates that a neuromorphic memory is also possible with 2D FeSFETs. These presented results facilitate the technological implementation of versatile 2D FeS devices for next‐generation logic‐in‐memory approach for Internet‐of‐Things entities. [ABSTRACT FROM AUTHOR]

We demonstrate complete control over dynamics of a single superconducting vortex in a nanostructure, which we coin the Single Vortex Box. Our device allows us to trap the vortex in a field-cooled aluminum nanosquare and expel it on demand with a nanosecond pulse of electrical current. Using the time-resolving nanothermometry we measure 4 · 10-19 joules as the amount of the dissipated heat in the elementary process of the single-vortex expulsion. Our experiment enlightens the thermodynamics of the absorption process in the superconducting nanowire single-photon detectors, in which vortices are perceived to be essential for a formation of a detectable hotspot. The demonstrated opportunity to manipulate a single superconducting vortex reliably in a confined geometry comprises a proof of concept of a nanoscale nonvolatile memory cell with subnanosecond write and read operations, which offers compatibility with quantum processors based either on superconducting qubits or on rapid single-flux quantum circuits. [ABSTRACT FROM AUTHOR]

This study explores the potential advantages of metal–ferroelectric–insulator–semiconductor (MFIS) structures compared with established metal–ferroelectric–semiconductor (MFS) and metal–ferroelectric–metal structures in the context of nonvolatile memory devices. Despite the superior performance of MFS structures in terms of electric field maintenance, switching speed, and power consumption, the presence of interface-related issues between the ferroelectric material and the semiconductor may degrade device performance. We propose an MFIS structure incorporating ultrathin interfacial layers (ILs) of SiO 2 , HfO 2 , and ZrO 2 to address these issues. These insulator layers enhance device endurance by reducing physical stress and trap density at the interface, thereby improving electrical performance and long-term stability. Moreover, the presence of an IL reduces charge leakage between the ferroelectric layer and semiconductor, contributing to the resolution of the sneak path current problem. An additional feature of MFIS devices is their self-rectifying behavior, simplifying circuit design and manufacturing processes by eliminating the need for an external rectification circuit, consequently reducing costs. Through a series of experiments, this study evaluates the performance of the MFIS structure, investigates the ferroelectric properties of HfAlOx-based FTJs, and examines the conduction mechanism of the MFIS structure. By comparing the o-phase of MFS, SiO 2 , HfO 2 , and ZrO 2 devices via grazing incidence X-ray diffraction (GIXRD) and using the positive-up-negative-down method to extract polarization and coercive voltage, we provide a comprehensive investigation of the impact of ultrathin ILs on ferroelectric properties. This research aims to offer valuable insights into the advancement of memory device technologies, presenting the MFIS structure as a promising platform for next-generation memory technologies. Further sections will elaborate on the experimental setup, methodology, and detailed study findings. [ABSTRACT FROM AUTHOR]

p‐type 2D ferroelectric semiconductors (2D FeSs) play an increasingly essential role in the advanced nonvolatile and morphotropic beyond‐Moore electronic devices with high performance and low power consumption. But reliable p‐type 2D FeS with holes as majority carriers are still scarce. Herein, the first experimental realization of room‐temperature ferroelectricity in van der Waals layered β‐In1.75Sb0.25Se3 down to few layer is reported. The origin of ferroelectricity in β‐In1.75Sb0.25Se3 comes from aliovalent elemental substitution, antimony substituting to the indium sites (SbIn), changing the local environment of the central‐layer Se atoms. Thanks to the intrinsic ferroelectric and semiconducting natures, FeS field‐effect transistor (FeSFET) devices based on β‐In1.75Sb0.25Se3 exhibit reconfigurable, multilevel nonvolatile memory (NVM) states, which can be successively modulated by gate voltage stimuli. Furthermore, the inherent operation mechanism, due to the switchable polarization, indicates that a neuromorphic memory is also possible with 2D FeSFETs. These presented results facilitate the technological implementation of versatile 2D FeS devices for next‐generation logic‐in‐memory approach for Internet‐of‐Things entities. [ABSTRACT FROM AUTHOR]

Multistate memory systems have the ability to store and process more data in the same physical space as binary memory systems, making them a potential alternative to existing binary memory systems. In the past, it has been demonstrated that voltage-controlled magnetic anisotropy (VCMA) based writing is highly energy-efficient compared to other writing methods used in non-volatile nano-magnetic binary memory systems. In this study, we introduce a new, VCMA-based and skyrmion-mediated non-volatile ternary memory system using a perpendicular magnetic tunnel junction (p-MTJ) in the presence of room temperature thermal perturbation. We have also shown that ternary states {− 1, 0, + 1} can be implemented with three magnetoresistance values obtained from a p-MTJ corresponding to ferromagnetic up, down, and skyrmion state, with 99% switching probability in the presence of room temperature thermal noise in an energy-efficient way, requiring ~ 2 fJ energy on an average for each switching operation. Additionally, we show that our proposed ternary memory demonstrates an improvement in area and energy by at least 2X and ~ 104X respectively, compared to state-of-the-art spin-transfer torque (STT)-based non-volatile magnetic multistate memories. Furthermore, these three states can be potentially utilized for energy-efficient, high-density in-memory quantized deep neural network implementation. [ABSTRACT FROM AUTHOR]

Quasi‐2D(two dimentional) perovskite is one of the potential materials in optoelectronic applications due to the scalable solution processes and low binding energy. Recent studies employing diverse spacer ligands of mono‐ and di‐amine functional groups to form Ruddlesden‐Popper (RP) and Dion‐Jacobson (DJ) phase perovskites efficiently manipulate the perovskite microstructure. However, there is a notable gap in investigating the performance of photomemory devices based on perovskites using different ligands and the accommodability in polymer matrixes. Herein, the perovskite with phenethylammonium bromide (PEABr) or p‐xylylenediamine (PDMA) ligands and methacrylate polymers comprising varied pendent groups (benzene and pyrene) are designed to investigate their effect. The results show that RP‐phase perovskite with polymer‐conferred pyrene group presented an excellent crystalline orientation, fewer grain boundaries, and higher charge transfer efficiency, attributed to superior accommodation between ligands and polymers and appropriate aggregation of pyrene groups. It demonstrates superior memory device characteristics of a high ON/OFF current ratio (2.68 × 104), low operational voltage (−0.1 V), short illumination times (0.1 s), and maintains its decent performance even under thermal environments. This work highlights that leveraging the steric hindrance of ligands and functional polymers to control the microstructure of perovskite is a prospective strategy to promote the photomemory's development. [ABSTRACT FROM AUTHOR]

The nanogap resistive switch holds potential as a candidate for nonvolatile memory, although its durability needs enhancement. This study delves into the operational mechanisms through detailed morphological examination during continuous operation of nanogap resistive switches. By developing a finite element model of nanogaps, we reveal the mechanisms behind the formation of electrode surface hillocks and filaments during continuous switching. Our findings suggest that "set" operations include processes such as field evaporation, electric field-induced diffusion, and field-assisted migration within the gap. Conversely, "reset" operations, driven by Joule heating and electromigration, lead to filament breakage and the creation of a fine gap. This research elucidates device degradation issues, such as periodic fluctuations in set threshold voltage (Vset) and the presence of non-steep set curves, providing both theoretical and experimental insights to improve future device performance. [ABSTRACT FROM AUTHOR]

Phase-change memory (PCM) using chalcogenide films composed of Ge–Sb–Te alloys is the only commercially available nonvolatile memory for storage class memory. Recently, superlattice films of GeTe and Sb2Te3, called interfacial PCM (iPCM), have attracted attention for further increasing the switching speed and reducing energy consumption. It has been reported that the iPCM device exhibits both unipolar- and bipolar-type resistive switching depending on the method of voltage application, and research is being conducted to advance its applications. However, all iPCMs reported thus far have been formed at high temperatures beyond the crystallization temperatures of GeTe and Sb2Te3 using vacuum chambers equipped with a heating stage, making mass production and practical application difficult. Here, we report on fabricated superlattice composed of S-doped GeTe and Sb2Te3 layers by combining room temperature deposition with subsequent two-step annealing. Upon evaluating the performance of this superlattice film as a bipolar-type iPCM, it was found to exhibit characteristics comparable to those of bipolar-type iPCM fabricated from high-temperature deposited superlattices. This technology is expected to contribute to an increase in the throughput of iPCM device manufacturing. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) ferroelectric materials exhibit significant potential for applications in nonvolatile memory and device miniaturization. In the device design stage, it is essential to consider the compatibility between 2D ferroelectric materials and three-dimensional (3D) metal. However, the interface between them introduces complex interactions that could impact the device's performance. In this work, based on the first-principles method, we simulate several 3D metal–2D ferroelectric material contact systems by utilizing different 3D metals in contact with the 2D ferroelectric monolayer CuInP2S6 (CIPS). By calculating the electronic structures of the systems, we find that the Cd(001)–CIPS configuration is the most stable structure, followed by the Ag(111)–CIPS and Au(111)–CIPS systems. Both the Cd(001)–CIPS and Ag(111)–CIPS systems undergo a transition from Schottky to Ohmic contact. Finally, we theoretically design a ferroelectric tunnel junction (FTJ) based on the Cd(001)–CIPS contact system, achieving a tunneling electroresistance ratio of 2.394 × 10 5 % and a remarkably low resistance–area product of 0.78 Ω · μ m2, which makes the proposed FTJ superior to the conventional 3D FTJ. This work provides some insights for the design of nonvolatile storage devices. [ABSTRACT FROM AUTHOR]

Neural network training can be slow and energy-expensive due to the frequent transfer of weight data between digital memory and processing units. Neuromorphic systems can accelerate neural networks by performing multiply-accumulate operations in parallel using nonvolatile analog memory. However, executing the widely used backpropagation training algorithm in multilayer neural networks requires information--and therefore storage--of the partial derivatives of the weight values preventing suitable and scalable implementation in hardware. Here, we propose a hardware implementation of the backpropagation algorithm that progressively updates each layer using in situ stochastic gradient descent, avoiding this storage requirement. We experimentally demonstrate the in situ error calculation and the proposed progressive backpropagation method in a multilayer hardware-implemented neural network. We confirm identical learning characteristics and classification performance compared to conventional backpropagation in software. We show that our approach can be scaled to large and deep neural networks, enabling highly efficient training of advanced artificial intelligence computing systems. [ABSTRACT FROM AUTHOR]

Ferroelectric materials have switchable electrical polarization that is appealing for high-density nonvolatile memories. However, inevitable fatigue hinders practical applications of these materials. Fatigue-free ferroelectric switching could dramatically improve the endurance of such devices. We report a fatigue-free ferroelectric system based on the sliding ferroelectricity of bilayer 3R molybdenum disulfide (3R-MoS2). The memory performance of this ferroelectric device does not show the wake-up effect at low cycles or a substantial fatigue effect after 106 switching cycles under different pulse widths. The total stress time of the device under an electric field is up to 105 s, which is long relative to other devices. Our theoretical calculations reveal that the fatigue-free feature of sliding ferroelectricity is due to the immobile charge defects in sliding ferroelectricity. [ABSTRACT FROM AUTHOR]

The persistence of voltage-switchable collective electronic phenomena down to the atomic scale has extensive implications for area- and energy-efficient electronics, especially in emerging nonvolatile memory technology. We investigate the performance of a ferroelectric field-effect transistor (FeFET) based on sliding ferroelectricity in bilayer boron nitride at room temperature. Sliding ferroelectricity represents a different form of atomically thin two-dimensional (2D) ferroelectrics, characterized by the switching of out-of-plane polarization through interlayer sliding motion. We examined the FeFET device employing monolayer graphene as the channel layer, which demonstrated ultrafast switching speeds on the nanosecond scale and high endurance exceeding 1011 switching cycles, comparable to state-of-the-art FeFET devices. These characteristics highlight the potential of 2D sliding ferroelectrics for inspiring next-generation nonvolatile memory technology. [ABSTRACT FROM AUTHOR]

High-density nonvolatile memories can be realized by fabricating resistive random-access memories (RRAMs) as 4F2 (F: minimum feature size) cells in a crossbar array (CBA) configuration. However, the CBA configuration induces leakage currents in the nearby cells, which significantly reduces the read-out margin and limits the CBA size extension. One solution to this problem is to integrate an RRAM with a bidirectional selector. Research on the various type of selector devices has been extensively explored so far, however, a device that satisfies all requirements has not been developed. In this paper, we propose a novel bidirectional diode selector with a Pt/HfNx/Pt stack. We implement a one-selector–one-resistor configuration in a 10 × 10 CBA by integrating Pt/HfNx/Pt with a Ti/HfO2/Pt RRAM stack. We confirm the stable resistive switching operation and good thermal stability of the selector and its integrated device. Chemical analyses aided by Auger electron spectroscopy and X-ray photoelectron spectroscopy reveal the gradient-oxidation of the HfNx film, which explains the nonlinear and asymmetric current–voltage characteristics. This novel nonlinear selector with simple structure and high thermal stability can be applied to build CBAs for high-density nonvolatile memories or neuromorphic computing elements, in the future. [ABSTRACT FROM AUTHOR]

Low‐power nonvolatile memories operating down to deep cryogenic temperatures are important for a large spectrum of applications from high‐performance computing, electronics interfacing quantum computing hardware to space‐based electronics. Despite the potential of Hf0.5Zr0.5O2 (HZO), thanks to its compatibility with complementary metal‐oxide‐semiconductor (CMOS) back‐end‐of‐line processing, only few studies of HZO‐based memory devices down to cryogenic operation temperatures exist. Here, analog ferroelectric memory stack fabrication with 10 nm HZO and their detailed characterization under wide range of pulse amplitudes and frequencies down to 4 K are reported. When operated at temperatures below 100 K, HZO devices can support high amplitude voltage pulses, yielding record high Pr of up to 75µC cm−2 at ±7 Vp (14 Vpp) pulse amplitudes accompanied with frequency‐dependent memory window between 6 and 8 V. Devices show excellent endurance exceeding 109 cycles of ±5 Vp (10 Vpp) and Pr of 30 µC cm−2 without significant degradation of coercive voltages or loss of polarization at cryogenic temperatures. At least 20 reproducible analog states for temperatures below 100 K with almost ideal linearity of intermediate polarization states in both pulse directions is observed, demonstrating the high potential of analog cryogenic ferroelectric memories, essential for on‐line training in in‐memory‐computing architecture. [ABSTRACT FROM AUTHOR]

In a ferromagnet/superconductor/ferromagnet (F/S/F) superconducting spin-valve (SSV), a change in the magnetization alignment of the two F layers modulates the critical temperature (Tc) of the S layer. The Tc-switching effect (the SSV effect) is based on the interplay between superconductivity and magnetism. The fast and large resistive switching associated with Tc-switching is suitable for nonvolatile cryogenic memory applications. However, the external magnetic field-based operation of SSVs is hindering their miniaturization, and therefore, electric field control of the SSV effect is desired. Here, we report epitaxial growth of a La0.67Ca0.33MnO3/YBa2Cu3O7/La0.67Ca0.33MnO3 SSV on a piezo-electric [Pb(Mg0.33Nb0.67)O3]0.7-[PbTiO3]0.3 (001) substrate and demonstrate electric field control of the SSV effect. Electric field-induced strain-transfer from the piezo-electric substrate increases the magnetization and Tc of the SSV and leads to an enhancement of the magnitude of Tc-switching. The results are promising for the development of magnetic-field-free superconducting spintronic devices, in which the S/F interaction is not only sensitive to the magnetization alignment but also to an applied electric field. [ABSTRACT FROM AUTHOR]

Herein we report on a facile sol-gel spin-coating technique to fabricate ZnO thin films that grow preferentially along the (002) plane on FTO substrates. By employing the magnetron sputtering technique to deposit a tungsten (W) top metal electrode onto these ZnO thin films, we successfully realize a W/ZnO/FTO memory device that exhibits self-rectifying and forming-free resistive switching characteristics. Notably, the as-prepared device demonstrates impressive nonvolatile and bipolar resistive switching behavior, with a high resistance ratio (RHRS/RLRS) exceeding two orders of magnitude at a reading voltage of 0.1 V. Moreover, it exhibits ultralow set and reset voltages of approximately +0.5 V and −1 V, respectively, along with exceptional durability. In terms of carrier transport properties, the low resistance state of the device is dominated by ohmic conduction, whereas the high resistance state is characterized by trap-controlled space-charge-limited current conduction. This work highlights the potential of the ZnO-based W/ZnO/FTO memory device as a promising candidate for future high-density nonvolatile memory applications. [ABSTRACT FROM AUTHOR]

Herein, a prototype nonvolatile bent ferroelastic domain wall (DW) memory based on extension–retraction of DWs in a top electrode/bent ferroelastic DWs/bottom electrode architecture is demonstrated and the effects of mechanical condition, electrical condition, and the material parameter on ferroelastic DWs in PbTiO3 ferroelectric thin films are studied by phase field modeling. Misfit strain can be used to drive the bend of DWs in PbTiO3 thin film, resulting in a change of ferroelastic domain size, bending degree, and conductivity. Stable and reversible switching of DWs between the extendible state with high conductivity and the retractile state with low conductivity can be realized, resulting in an apparent resistance change with a large ON/OFF ratio of >102 and an excellent retention characteristic. The extension and retraction speed, corresponding to data writing speed, can be adjusted by the electric field magnitude and distributions. The memory speed increases by 5% under a homogeneous electric field and 6% under an inhomogeneous probing electric field, after the buildup of space charges in a ferroelectric thin film, and the fastest memory speed is obtained at tip potential φ = 1.8. Moreover, polarization orientations of a and c domains separated by bent ferroelastic DWs do not affect memory performance. This paper can guide the development of new ferroelectric domain wall memory. [ABSTRACT FROM AUTHOR]

Phase-change memory (PCM) is one of the leading candidates for the next generation nonvolatile memory. As a growth-dominated crystalline material, Sb2Te3 is of rapid crystallization speed while its poor thermal stability limits its application. Doping Ti can significantly enhance its amorphous stability but inevitably slows down its crystallization speed. How to balance the contradiction between thermal stability and operation speed remains challenging. In this work, we proposed a gradient Ti-doped Sb2Te3 phase-change material and device. This gradient doping strategy compensates for the negative effect of Ti doping on the crystallization rate of Sb2Te3 via the template effect of the lower doping concentration layer. Very small lattice mismatch between the Sb2Te3 layers with different Ti doping concentrations is verified by x-ray diffraction characterization. The crystallization temperature of a gradient Ti-doped Sb2Te3 thin film is raised up to 172.6 °C and the same 50 ns operation speed as a pure Sb2Te3 device is achieved in the corresponding PCM device. Furthermore, the gradient distribution of Ti elements and the corresponding progressive crystallization phenomenon are verified by transmission electron microscopy revealing the microscopic origin of rapid crystallization speed. Therefore, with our gradient doping strategy, the amorphous stability is improved without sacrificing the crystallization speed in PCM. [ABSTRACT FROM AUTHOR]

Low‐band gap semiconductor polymer materials play a crucial role in the field of organic optoelectronics. In this context, a series of low‐band gap polymers containing thienopyrazine as the acceptor and cyclofluorene–bithiophene as the donor were synthesized and utilized in resistive random access memory (RRAM) devices. These memory devices consistently exhibit nonvolatile flash memory behavior. Remarkably, all three polymers demonstrate stability even after 1000 cycles without significant fluctuations. Notably, the three polymer‐based devices also exhibit excellent ternary memory performance, with current ratios of 1:102.8:104, 1:101.3:103.9, and 1:101.8:103.6. Furthermore, the photoelectric properties of the three polymers and the conduction mechanisms of the memory devices were thoroughly discussed. [ABSTRACT FROM AUTHOR]

Thin-film ferroelectric doped hafnia has emerged as a promising candidate for non-volatile computer memory devices due to its CMOS compatibility. The ferroelectricity in thin-film HfO2 is defined by the polar orthorhombic phase, whose stabilization depends on various parameters, such as doping species, stress, thickness, crystallization annealing temperature, etc. The concentration of oxygen vacancies is yet another parameter affecting the stabilization of the ferroelectric phase in HfO2 thin films. Here, we report on the effect of oxygen vacancies introduced in Y-doped HfO2 (HYO) films during reactive pulsed laser deposition on their ferroelectric properties, which we systematically study by correlating structural and electrical properties. Among different techniques, near-edge x-ray absorption fine structure analysis is successfully employed to distinguish between structurally similar ferroelectric orthorhombic and paraelectric tetragonal phases. It is shown that oxygen vacancies introduced at a certain concentration in HYO films can be used as a tool to control the phase composition as well as to decrease the formation energy (crystallization temperature) of the ferroelectric phase. Based on these results, we demonstrate a back-end-of-line compatible ferroelectric HYO capacitor device with competitive functional properties. [ABSTRACT FROM AUTHOR]

Highlights Ferroelectricity and domain dynamics of emerging ferroelectric AlScN films were discussed. The performance optimization of ferroelectric AlScN films grown by different deposition techniques was comprehensively analyzed. The challenges and perspectives regarding the commercial avenue of AlScN-based memories and in-memory computing applications were summarized.

Recently, metal–organic frameworks (MOFs) have gained attention in the field of electronics owing to their capability to tune their electrical characteristics. However, conventional methods for synthesizing MOFs pose challenges for their integration into electronic devices because of their long synthesis times and complex transfer steps. In this study, for the first time, lasing‐assisted synthesis (LAS) is used to rapidly and directly synthesize MOFs. These are applied to resistive random access memory (RRAM) devices. Using the LAS method, Cu(BDC) and Cu(BTC) are synthesized in a remarkably short time (≈5 min) and formed directly on metal substrates as thin films. This simplified their integration into RRAMs. The Cu(BDC)‐ and Cu(BTC)‐based RRAMs are evaluated for their potential in memory and neuromorphic applications. Both devices demonstrated nonvolatile memory capabilities with a remarkable data retention time of 104 s and long‐term plasticity (LTP) in response to voltage stimuli. However, the suitability of each device for a specific application varies depending on the type of MOFs used. The Cu(BTC)‐based RRAM is more suitable for memory applications because of its higher on/off ratio, longer endurance, and more data storage capacity. Conversely, Cu(BDC)‐based RRAM is highly effective in neural network simulation, achieving higher classification accuracy. [ABSTRACT FROM AUTHOR]

Highlights: Ferroelectricity and domain dynamics of emerging ferroelectric AlScN films were discussed. The performance optimization of ferroelectric AlScN films grown by different deposition techniques was comprehensively analyzed. The challenges and perspectives regarding the commercial avenue of AlScN-based memories and in-memory computing applications were summarized. Ferroelectrics have great potential in the field of nonvolatile memory due to programmable polarization states by external electric field in nonvolatile manner. However, complementary metal oxide semiconductor compatibility and uniformity of ferroelectric performance after size scaling have always been two thorny issues hindering practical application of ferroelectric memory devices. The emerging ferroelectricity of wurtzite structure nitride offers opportunities to circumvent the dilemma. This review covers the mechanism of ferroelectricity and domain dynamics in ferroelectric AlScN films. The performance optimization of AlScN films grown by different techniques is summarized and their applications for memories and emerging in-memory computing are illustrated. Finally, the challenges and perspectives regarding the commercial avenue of ferroelectric AlScN are discussed. [ABSTRACT FROM AUTHOR]

Crystalline metal halide perovskites (MHPs) have ushered in remarkable advancements across diverse fields, including materials, electronics, and photonics. While the advantages of crystallinity are well‐established, the ability to transition to a glassy state with unique properties presents unprecedented opportunities to expand the structure‐property relationship and broaden the application scope for 2D MHPs. Up until now, the exploration of amorphous analogs for MHPs is confined to high‐pressure conditions, limiting in‐depth studies and practical applications. In this context, a new type of 2D MHPs is synthesized by incorporating halogen substituted organic cations, resulting in a remarkable combination of low melting temperature and inhibited crystallization. This new type of 2D MHPs can be effectively melt‐quenched into a glassy state except for (DMIEA)3Pb2I7 (DMIEA = N, N‐dimethyl iodoethylammonium) counterpart. Analysis of the crystallization activation energy for (DMIPA)4Pb3I10 (DMIPA = N, N‐dimethyl iodopropylammonium) reveals a low crystallization activation energy of 60.7 ± 4.0 kJ mol−1, which indicates a fast glass‐crystal transition. The type of atypical 2D MHP showcases facile and reversible switching between glassy and crystalline states and opens up novel possibilities for applications, such as nonvolatile memory, optical communication, and neuromorphic computing. [ABSTRACT FROM AUTHOR]

Over the past decade, molecular‐switch‐embedded memory devices, particularly field‐effect transistors (FETs), have gained significant interest. Molecular switches are integrated to regulate the resistance or current levels in FETs. Despite substantial efforts, realizing large memory window with a long retention time, a critical factor in memory device functionality, remains a challenge. This is due to the inability of an isomeric state of a molecular switch to serve as a stable deep trap state within the semiconductor layer. Herein, the study addresses this limitation by introducing chemical bonding between molecular switch and conjugated polymeric semiconductor, facilitating closed isomer of diarylethene (DAE) to operate as a morphologically stable deep trap state. Azide‐ and diazirine‐anchored DAEs are synthesized, which form chemical bonds to the polymer through photocrosslinking, thereby implementing permanent and controllable trapping states nearby conjugated backbone of polymer semiconductor. Consequently, when diazirine‐anchored DAE is blended with F8T2 and subjected to photocrosslinking, the resulting organic FETs exhibit remarkable memory performance, including a memory window of 22 V with a retention time over 106 s, a high photoprogrammable on/off ratio over 103, and a high operational stability over 100 photocycles. Further, photophore‐anchored DAEs can achieve precise patterning, which enables meticulous control over the semiconductor layer structure. [ABSTRACT FROM AUTHOR]

Multiferroic materials have important research significance in the fields of magnetic random-access memory, ferroelectric random-access memory, resistive random-access memory, and neuromorphic computing devices due to their excellent and diverse physical properties. In this work, a solution of Bi2FeMnO6 was prepared using a solution-based method, and an Au/Bi2FeMnO6/TiO2 heterostructure device was fabricated on a Si substrate. X-ray diffraction and transmission electron microscopy data indicate that the Bi2FeMnO6 films have hexagonal R3c symmetry structures. The Bi2FeMnO6 film exhibits ferroelectricity with a fine remanent polarization. In addition, the Bi2FeMnO6-based devices have excellent switching ratios of 6.37 × 105. A larger switching ratio can provide a multi-resistance state for the device, which is beneficial for the simulation of synapses. Hence, it effectively emulates excitatory postsynaptic currents, paired-pulse facilitation, and long-term plasticity of synapses and achieves recognition accuracy of 95% in neuromorphic computing. We report a promising material for the development of various nonvolatile memories and neuromorphic synaptic devices. [ABSTRACT FROM AUTHOR]

High-performance organic devices with dynamic and stable modulation are essential for building devices adaptable to the environment. However, the existing reported devices incorporating light-activated units exhibit either limited device stability or subpar optoelectronic properties. Here, we synthesize a new optically tunable polymer dielectric functionalized with photochromic arylazopyrazole units with a cis-isomer half-life of as long as 90 days. On this basis, stable dual-mode organic transistors that can be reversibly modulated are successfully fabricated. The trans-state devices exhibit high carrier mobility reaching 7.4 square centimeters per volt per second and excellent optical figures of merit, whereas the cis-state devices demonstrate stable but starkly different optoelectronic performance. Furthermore, optical image sensors are prepared with regulatable nonvolatile memories from 36 hours (cis state) to 108 hours (trans state). The achievement of dynamic light modulation shows remarkable prospects for the intelligent application of organic optoelectronic devices. [ABSTRACT FROM AUTHOR]