Abstract A comprehensive analysis of temperature-dependent photoluminescence (PL) spectroscopy in Nb3O7(OH) is presented. Three emission bands at 410, 430, and 465 nm are deconvoluted via multi-peak Gaussian fitting across the temperature range of 10–190 K. The temperature evolution of the full width at half maximum (FWHM) for each band is analyzed using a single-mode phonon broadening model. All three peaks exhibit consistent phonon energy of ∼32 meV, attributed to the Nb–O–Nb bending vibration local mode. The Huang–Rhys factor S = 0.83 ± 0.08 indicates moderate electron–phonon coupling strength. Arrhenius analysis independently confirms the dominance of phonon occupation number in the line width broadening mechanism. Based on the consistent Huang–Rhys factors and shared phonon energy, the three emission peaks are assigned to different charge states of oxygen vacancies: VO2+(410 nm), VO+(430 nm), and VO0 (465 nm).

Lanthanide-based nanomaterials have attracted increasing attention as photothermal agents for cancer therapy. However, achieving high photothermal conversion efficiency while maintaining good biocompatibility remains a significant challenge. In this work, lanthanide coordination nanocrystals with a silver ragwort-like architecture were constructed through the coordination of La 3+ ions with an amino ligand, 1,5-diaminonaphthalene, forming a La–amine coordination platform (LN5). Through crystal phase modulation via ultrasonic treatment and heterometal co-doping with Eu 3+ and Gd 3+ ions, two types of coordination nanocrystals, LN5(I) and LN5Eu 3+ Gd 3+ , were successfully engineered with controlled particle sizes of approximately 15 ± 5 nm and 20 ± 5 nm, respectively. The heterometal doping strategy not only regulated the crystallographic evolution of the coordination framework but also altered the energy dissipation pathways, leading to distinct optical and photothermal properties. LN5(I) exhibited yellow fluorescence emission centered at approximately 569 nm, whereas LN5Eu 3+ Gd 3+ displayed a purple emission band within the range of 350–450 nm, enabling potential dual-modal imaging capabilities. Importantly, both coordination nanocrystals demonstrated remarkable photothermal conversion efficiencies under 808 nm near-infrared (NIR) irradiation, reaching 63.9% for LN5 and 67.1% for LN5Eu 3+ Gd 3+ . In vitro photothermal experiments revealed that the temperature of the nanocrystal dispersion increased to above 60 °C within 10 min of NIR irradiation. In vivo thermal imaging further confirmed that the tumor-site temperature rapidly exceeded 50 °C under the same irradiation conditions, leading to effective thermal ablation of tumor tissues.Comprehensive biosafety assessments indicated low cytotoxicity and minimal immune interference. In vivo antitumor studies demonstrated significant tumor growth suppression, particularly in the LN5Eu 3+ Gd 3+ combined with laser irradiation group. Overall, this work establishes amino-ligand coordinated lanthanide nanocrystals as promising photothermal theranostic platforms, integrating efficient photothermal therapy with fluorescence imaging capabilities for potential applications in cancer nanomedicine.

The performance of memristive devices is fundamentally determined by the microstructure of the dielectric layer and the associated charge-transport mechanisms. Here, we report a precursor-directed microstructure engineering strategy to modulate copper sulfide (CuS) films through a room-temperature chemical bath deposition process. By simply switching the copper precursor from CuCl2 to CuSO4, the CuS morphology evolves from dense microspheres to a nanoparticle-assembled (NPA) porous architecture. This structural transformation induces a transition in the dominant transport mechanism from Schottky emission to Fowler-Nordheim (FN) tunneling. Systematic electrical analysis reveals a transition voltage of -0.52 V, corresponding to the onset of FN tunneling. The ratio between the transition voltage and the extracted barrier height (0.62 eV) falls within the theoretical range of 0.8-1.2, derived by equating direct tunneling and FN tunneling current densities under the Wentzel-Kramers-Brillouin (WKB) approximation. Fitting results yield a barrier width of similar to 1.8 nm and trap energy depths of 0.15-0.18 eV, providing quantitative evidence for tunneling-dominated and trap-assisted transport in the NPA structure. Furthermore, modulation of the bottom electrode work function enables control over switching polarity and rectification direction. Neural network simulations based on experimentally measured synaptic characteristics achieve 93% accuracy on the Fashion-MNIST dataset within 30 training epochs. This work establishes a quantitative structure-mechanism-function correlation and provides a physically grounded framework for the rational design of customizable neuromorphic devices.

The conduction and valence band edges for the electronic band gaps and Fermi levels of CuS are determined by ultraviolet photoelectron spectroscopy and electrochemical analysis. The experimentally measured effective hole mass of CuS is about 1.5 m 0, which is very close to the theoretical result (1.54 m 0). The obtained value of the effective hole mass of CuS successfully elucidates the carrier transfer behaviors in Ag/CuS/Ti Schottky barrier diodes. The theoretical Richardson constant is 170.3 A/cm2 K2. The room-temperature ideality factor is 2.11, and the effective Richardson constant (1.85 A/cm2 K2) is extracted from the variable temperature I-V curve. The difference in barrier height between the theoretical value (0.66 eV) and the I-V curve result (0.37 eV) is attributed to inhomogeneity and defect-induced tunneling. According to the inhomogeneous Schottky barrier theory, the corrected barrier height and Richardson constant are 0.62 eV and 166.8 A/cm2 K2, respectively.

All-optical modulators are crucial in optical communication, quantum communication, and microwave photonics, owing to their low insertion loss and high efficiency. Thermo-optical modulators, a key subset of alloptical modulators, have been extensively studied, particularly those based on fiber optics and twodimensional materials. However, silicon photonic modulators incorporating two-dimensional materials remain relatively underexplored. This paper introduces a novel thermally induced phase shift model to provide a deeper understanding of the effects of thermal phase shifts on waveguide modes. A Mach-Zehnder interferometric modulator, utilizing graphene oxide thin films and silicon photonic technology, was designed, fabricated, and experimentally characterized. The sensor exhibited a sensitivity of 0.02127 dB/degrees C, with a linear fitting coefficient (R2) of 0.99905 over a temperature range of 25-55 degrees C. Furthermore, the phase modulator exhibited a modulation efficiency of 0.03596 rad/mW, with a linear fitting coefficient of 0.99359. The proposed thermal phase shift model can serve as a novel framework for designing and optimizing thermal modulators based on two-dimensional materials, offering valuable insights for future research and development in this field.

Convolutional Neural Networks (CNNs), as a core component of deep learning, have achieved groundbreaking results in various application domains, particularly in tasks such as computer vision and speech recognition. However, as CNN models continue to grow in complexity, the computational and storage overheads have also increased, leading to energy efficiency and latency becoming bottlenecks in both training and inference processes. To address this issue, this paper proposes a configurable multi-precision CNN computing framework based on single-bit Resistive Random-Access Memory (RRAM). The framework employs a software-hardware co-design approach, integrating quantization algorithms, pruning optimization, and parallel computing techniques to achieve lower storage consumption and latency while maintaining accuracy comparable to full-precision CNNs. Specifically, we design a dynamic quantization precision adjustment scheme that adaptively selects the precision for each layer based on hardware resources and computational demands. Additionally, we propose a quantization optimization model to address hardware computation deviations and design a multi-precision RRAM architecture. Experimental results demonstrate that the framework reduces computational area by approximately 70% and computational energy by 75%, while achieving an energy efficiency improvement of 6.1 to 8.6 times compared to existing RRAM-based accelerators, with only a 1.07% increase in area overhead.

Memristors are considered the best candidates for nonvolatile memory and advanced computing technologies, and polymer and two-dimensional (2D) materials have been developed as functional layer materials in memristors with high-performance resistive switching characteristics. In this work, a polymer memristor with a graphene (Gr)-doped poly(vinyl alcohol) (PVA) composite acting as the functional layer was prepared. The memristor device exhibited superior performance with good retention and a comparatively large ON/OFF ratio at room temperature. Additionally, excellent logic operations were achieved. These satisfactory properties can be attributed to trap-induced carrier trapping and detrapping. In addition, the device exhibited stable bipolar resistive switching behavior over a moderate temperature range. This work provides insight into the transmission mechanism of polymer-based memristors and the reasons why they become unstable at high temperatures, demonstrating the potential applications of PVA-Gr-based polymer memristors as logic circuit units in integrated chips and artificial intelligence.

Despite the excellent performance of Nb3O7(OH) in dye-sensitized solar cells and catalysis, its charge separation, transport, and structural properties remain poorly understood. Herein, the Nb3O7(OH) nanorods were prepared, and their structural characteristics, optoelectronic properties, and carrier mobility were also analyzed and investigated through a series of complex characterizations. Theoretical prediction suggested that the exciton binding energy of Nb3O7(OH) could be as high as 100.49 meV. The temperature-dependent photoluminescence (PL) of Nb3O7(OH) nanorods revealed two activation energies, and a higher proportion of long-lived components observed in the photoluminescence decay indicated effective electron trapping. That is, two energy states were present, hindering photogenerated charge recombination and promoting photocatalytic action. Current-voltage characteristics of the Nb3O7(OH) nanorod film were analyzed, revealing an ultrahigh carrier mobility of similar to 310 cm(2)/Vs, ensuring fast and efficient electron transfer. Furthermore, Nb3O7(OH) nanorods were employed to reduce CO2, resulting in the effective production of CO and CH4. Overall, considering the presence of hydroxyl pairs on the surface of Nb3O7(OH), which facilitate the formation of the frustrated Lewis acid-base pairs and the activation of CO2, together with its effective electron trapping and charge transport, give Nb3O7(OH) nanorods a promising potential for CO2 reduction.

Memristor has a high-density information storage capability and can manipulate a large amount of data computing in parallel, so it can be applied in neuromorphic computing. The advanced intelligent applications are one of the major breakthroughs made in the past decade based on the memristor's research. In this work, amorphous Nb2O5 film as functional layers on flexible niobium (Nb) foil were fabricated by anodic oxidation in oxalic acid aqueous solution. A broad spectrum of well-defined color was acquired by varying the anodic voltage during oxidation of the Nb foil. The results of spectroscopic ellipsometry (SE) tests show that the Nb2O5 layers with various colors have different thickness. The willow yellow Nb2O5 film with a thickness of similar to 85 nm based memristor show an excellent memristive memory behavior. Finally, it was proposed that the potential well of the ionization center tilts under the external electric field, which causes the probability of charge to escape along and against the direction of the external electric field to explain the memristive effect of the device. This work opens up a new method for fabricating the flexible memristor, which provides the potential applications for next generation self-color electronics.

H-Nb2O5 is a promising energy material, which can be typically obtained from any other polymorph after conducting high temperature calcination (∼1273 K). Recently, a low-temperature dehydration from Nb3O7(OH) was employed to prepare H-Nb2O5 at 723 K for 2 h, and yet the transformation mechanism has remained unclear in the literature. Here, the dehydration kinetic and phase transformation mechanism of the Nb3O7(OH) were investigated for the first time by experiments, density functional theory, and molecular dynamics calculations. After dehydration, the orthorhombic Nb3O7(OH) initially transformed into an intermediate Nb-O compound with dislocations, preserving parent structure, and subsequently transformed into monoclinic H-Nb2O5. The activation energy for the transformation from Nb3O7(OH) to H-Nb2O5 was as low as 1.35 eV, compared to that of T-Nb2O5 to H-Nb2O5 (3.60 eV). Furthermore, the defect-rich H-Nb2O5 obtained from Nb3O7(OH), does not exhibit pristine bound exciton state due to severe recombination of photogenerated carriers, resulting in poor photocatalytic activity.

Since memristors as an emerging nonlinear electronic component have been considered the most promising candidate for integrating nonvolatile memory and advanced computing technology, the in-depth reveal of the memristive mechanism and the realization of hardware fabrication have facilitated their wide applications in next-generation artificial intelligence. Flexible memristors have shown great promising prospects in wearable electronics and artificial electronic skin (e-skin), but in-depth research on the physical mechanism is still lacking. Here, a flexible memristive device with a Ag/HfOx/Ti/PET crossbar structure was fabricated, and a remarkable analog switching characteristic similar to synaptic behavior was observed. Through detailed data fitting and in-depth physical mechanism analysis, it is confirmed that the analog switching characteristics of the device are mainly caused by carrier tunneling. Furthermore, the memristive properties of the Ag/HfOx/Ag/PET device can be attributed to the conductive filaments formed by the redox reaction of the active metal Ag. Finally, the interfacial barrier is extracted by the Arrhenius diagram and the energy band diagram, which is drawn to clearly demonstrate the conduction mechanism of charge trapping in the device. Therefore, the HfOx-based flexible memristor with analog switching behavior and stable memory performance lays the foundation for cutting-edge applications in wearable electronics and smart e-skin.

Improvement of memristors’ performance is of great significance for the development of artificial intelligence and electronic circuits. Among them, the development of optical memristors is very important for simulating the process of receiving information from a visual system. In this work, a BiFeO3-based memristor was fabricated and its performance was enhanced by adding Ti3C2 to form a heterojunction structure. The Ag/BiFeO3/Ti3C2/FTO memristor exhibited a stable coexistence of resistive switching and negative different resistance at room temperature. After data fitting and calculation, electron transmission in the forward voltage bias region was dominated by Schottky emission and F–N tunneling, while in the negative voltage bias region, it was mainly Schottky emission. It was also found that the device could be tunable by light. The high resistance state/low resistance state ratio obtained under illumination was ~ 9.2, which is more than twice as high as that under normal conditions. The reason for the improvement of the device’s performance under illumination conditions was considered to be the photoelectric field generated which led to the electron motion being suppressed.

The development of a memristor is very important for artificial intelligence and new electronic circuits. In this work, Ag(Al)/ZnO/WOx/FTO memristors are fabricated by magnetron sputtering, and the device performance is further improved through annealing and oxygen supply during sputtering. The experimental data show that the FTO/WOx/ZnO-O2/Ag memristor has the largest high resistance state (HRS)/low resistance state (LRS) resistance ratio and the best durability. Through data fitting and analysis, the switching mechanism of memristors with different top electrodes is investigated. Furthermore, the physical model of the best performance memristor was established by Simulink, and an emotion-monitoring circuit was constructed on this basis. The circuit can be used to monitor and record the mood changes, and the feedback of the emotion monitoring can be fed back to the user to help them adjust the mood.

With the advent of high-tech eras with big data, artificial intelligence and 5G communications, people have higher and higher requirements for computer performance. The traditional von Neumann architecture, whose principle is the separation of the central processing unit (CPU) and memory, not only limits the performance of the computer, but also causes a lot of energy consumption. The next generation of brain-inspired computing chips promises to break the von Neumann bottleneck by simulating the brain's neural networks, enabling a new computer architecture known as neuromorphic computing. Memristors have been found to be one of the best pieces of hardware for neuromorphic computing and the best components for building artificial neural networks. This review systematically summarizes the research progress of biomemristors as synaptic devices. Memristors and bio-synapses are first introduced, and then the research progress of biomemristors based on biomaterials and polymers is reported. Finally, the application prospects and challenges of biomemristors in synapses are pointed out. This review provides a research perspective for the application of biomemristors-based synaptic devices in artificial intelligence.

Extra-factors-controlled ReRAM devices are expected to be used in the manufacture of multistate memory and artificial intelligent sensors.

Memristors and memcapacitors with threshold voltages have a great potential for chaotic circuit design, memory, and neuromorphic systems. Numerous physical experiments have shown the existence of resistance and capacitance coupling changes phenomenon in some voltage-controlled memristors. In this brief, a voltage threshold adaptive memcapacitive-coupled memristor (VTEAM-M) model is proposed to describe the behavior of resistance-capacitance coupling changes and multiple memristive states of voltage-controlled memristors. The core idea of the model is to divide the device into multiple states, each state corresponds to an equivalent dielectric constant function and an equivalent resistivity function, and then use state variables to represent the superposition and transition between states. The VTEAM-M model retaining the accuracy of Voltage ThrEshold Adaptive Memristor (VTEAM) model in resistance simulation, additionally, adds the modeling of multiple memristive states and capacitance changes of devices. The simulation results are in good agreement with the variation of resistance and capacitance with voltage in real devices.

The development of multifunctional electric device is of great significance for improving the integration dense of integrated circuits in the future. Herein, amorphous WO x -based memristor was fabricated and the mechanism of resistance switching was studied in detail. The device exhibited a stable coexistence of bipolar resistive switching (RS) and negative differential resistance (NDR) behaviors at room temperature, which could modulated by changing the annealing time at 300 °C. The optimal high-resistance state (HRS)/low-resistance state (LRS) resistance ratio of ~30 was obtained by postannealing in 100 min. However, both RS and NDR behaviors disappeared with the crystallization of amorphous films when the annealing time was 300 min. The Ohmic conduction mechanism should be responsible for the charge transport of LRS, while the HRS transmission was corporately dominated by the trap-controlled space charge limited conduction (SCLC) and Poole-Frenkel (P-F) emission. The change of trap levels modulated by postannealing was calculated and considered to be the reason for the change of RS and NDR behaviors. Raman spectroscopy provided evidence for the formation of strong W-O bonds, which contributed to the disappearance of RS and NDR behaviors.

The unique electron spin, transfer, polarization and magnetoelectric coupling characteristics of ABO3 multiferroic perovskite materials make them promising candidates for application in multifunctional nanoelectronic devices. Reversible ferroelectric polarization, controllable defect concentration and domain wall movement originated from the ABO3 multiferroic perovskite materials promotes its memristive effect, which further highlights data storage, information processing and neuromorphic computing in diverse artificial intelligence applications. In particular, ion doping, electrode selection, and interface modulation have been demonstrated in ABO3-based memristive devices for ultrahigh data storage, ultrafast information processing, and efficient neuromorphic computing. These approaches presented today including controlling the dopant in the active layer, altering the oxygen vacancy distribution, modulating the diffusion depth of ions, and constructing the interface-dependent band structure were believed to be efficient methods for obtaining unique resistive switching (RS) behavior for various applications. In this review, internal physical dynamics, preparation technologies, and modulation methods are systemically examined as well as the progress, challenges, and possible solutions are proposed for next generation emerging ABO3-based memristive application in artificial intelligence.

Using the first-principles density functional theory, we have studied the structural, excitonic and electronic properties of Nb2O5 with five different crystal structures. In this paper, the structural characteristics of monoclinic, orthorhombic and tetragonal systems have been studied. Different from the classical layered structure, Nb2O5 is a layered shear structure composed of a certain number of NbO6 octahedrons. Exciton effect plays an important role in the physical process of semiconductor. The absorption and recombination of excitons directly affect the light absorption and luminescence of semiconductors. In order to explore the strength of exciton effect, the binding energy of exciton is calculated. By calculating the exciton binding energies, we found that the exciton binding energy for monoclinic Nb2O5 (the space group is C2/c) and orthorhombic Nb2O5 were as high as 69.611 and 75.548 meV. The high exciton binding energy is mainly due to the weak dielectric shielding ability and effective electron hole coulomb interaction. The microcosmic reasons for the difference of exciton binding energies in different crystal structures were analyzed by electrical properties. By analyzing the energy band diagram, it is found that the band gap is closely related to the excitonic binding energy. In general, the position of the atom, the shape of the energy band and the strength of the bond are all factors that contribute to the differences in exciton binding energy.