Next-generation Electronics Research Articles

Probing electron trapping by current collapse in GaN/AlGaN FETs utilizing quantum transport characteristics

GaN is expected to be a key material for next-generation electronics due to its interesting properties. However, current collapse poses a challenge to the application of GaN FETs to electronic devices. In this study, we investigate the formation of quantum dots in GaN FETs under current collapse. By comparing the Coulomb diamond between standard measurements and those under current collapse, we find that the gate capacitance is significantly decreased under current collapse. This suggests that the current collapse changes the distribution of trapped electrons at the device surface, as reported in the previous study by operando x-ray spectroscopy. In addition, we show external control of quantum dot formation, previously challenging in an FET structure, by using current collapse.

The Model and Simulation of Memristor

Memristor is an emerging electronic component, tremendous efforts have been made in the fields of memristor, motivated by its unique resistor switching feature, as well as the good compatibility with the current integrated circuit (IC) technologies. It has been widely accepted that memristor would be a powerful candidate for constructing the brain-like computing hardware system in the next generation of electronics. Even so, there are still challenges in the development of the memristor IC and the calculation system based on it. For an example, the lack of memristor simulation module hinders its automatic design. Herein, we would like to propose a method for simulating the feature of the memristor. Firstly, based on the conductive filament based physical principle of memristor, calculations are conducted to simulate the basic electronic features of memristor. The good fitness confirms the feasibility of the proposed method. Second, the memristor’s resistance switching feature is modelled by Spice, a popular design platform. With the use of Voltage-Controlled Current Source (VCCS) in Spice, a modulus of memristor is established and executed to simulate the switched resistances under different bias voltages. In summary, this work demonstrates the feasibility of the proposed simulating method, it may provide an easy-to-operate way to improve design efficiency of active memristor arrays

Breaking the Trade-Off Between Mobility and On-Off Ratio in Oxide Transistors.

Amorphous oxide semiconductors (AOS) are pivotal for next-generation electronics due to their high electron mobility and excellent optical properties. However, In2O3, a key material in this family, encounters significant challenges in balancing high mobility and effective switching as its thickness is scaled down to nanometer dimensions. The high electron density in ultra-thin In2O3 hinders its ability to turn off effectively, leading to a critical trade-off between mobility and the on-current (Ion)/off-current (Ioff) ratio. This study introduces a mild CF4 plasma doping technique that effectively reduces electron density in 10nm In2O3 at a low processing temperature of 70°C, achieving a high mobility of 104 cm2 V⁻¹ s⁻¹ and an Ion/Ioff ratio exceeding 10⁸. A subsequent low-temperature post-annealing further improves the critical reliability and stability of CF4-doped In2O3 without raising the thermal budget, making this technique suitable for monolithic three-dimensional (3D) integration. Additionally, its application is demonstrated in In2O3 depletion-load inverters, highlighting its potential for advanced logic circuits and broader electronic and optoelectronic applications.

Diamond micro-chip for quantum microscopy

The nitrogen-vacancy (NV) center in diamond is an increasingly popular quantum sensor for microscopy of electrical current, magnetization, and spins. However, efficient NV–sample integration with a robust, high-quality interface remains an outstanding challenge to realize scalable, high-throughput microscopy. In this work, we characterize a diamond micro-chip (DMC) containing a (111)-oriented NV ensemble and demonstrate its utility for high-resolution quantum microscopy. We perform strain imaging of the DMC and find minimal detrimental strain variation across a field of view of tens of micrometer. We find good ensemble NV spin coherence and optical properties in the DMC, suitable for sensitive magnetometry. We then use the DMC to demonstrate wide-field microscopy of electrical current and show that diffraction-limited quantum microscopy can be achieved. We also demonstrate the deterministic transfer of DMCs with multiple materials of interest for next-generation electronics and spintronics. Lastly, we develop a polymer-based technique for DMC placement. This work establishes the DMC's potential to expand the application of NV quantum microscopy in materials, device, geological, biomedical, and chemical sciences.

Ferroelectric Perovskite/MoS2 Channel Heterojunctions for Wide-Window Nonvolatile Memory and Neuromorphic Computing.

Ferroelectric materials commonly serve as gate insulators in typical field-effect transistors, where their polarization reversal enables effective modulation of the conductivity state of the channel material, thereby realizing non-volatile memory. Currently, novel 2D ferroelectrics unlock new prospects in next-generation electronics and neuromorphic computation. However, the advancement of these materials is impeded by limited selectivity and narrow memory windows. Here, new concepts of 2D ferroelectric perovskite/MoS2 channel heterostructures field-effect transistors are presented, in which 2D ferroelectric perovskite features customizable band structure, few-layered ferroelectricity, and submillimeter-size monolayer wafers. Further studies reveal that these devices exhibit unique charge polarity modulation (from n- to p-type channel) and remarkable nonvolatile memory behavior, especially record-wide hysteresis windows up to 177V, which enables efficient imitation of biological synapses and achieves high recognition accuracy for electrocardiogram patterns. This result provides a device paradigm for future nonvolatile memory and artificial synaptic applications.

A flexible, sustainable, and deep learning-assisted triboelectric patch for self-powered interactive sensing and wound healing applications

Multi-functional cellulose-based triboelectric nanogenerators (TENGs) with sensing and energy-harvesting capabilities are emerging as promising candidates for next-generation healthcare electronics. However, insufficient output performance and device sustainability limits their further application. In this study, we developed a SnS₂-based nanocomposite with tunable surface triboelectric properties, simulated by Density Functional Theory (DFT) and characterized via Kelvin Probe Force Microscopy (KPFM). The SnS₂-based nanocomposite was then integrated into a cellulose-based TENG (C-TENG) to enhance output performance and function as a biomechanical sensing medium for human motion monitoring. A one-dimensional geometric fast data density functional transform (1-D g-fDDFT) model was also employed to improve the as-designed sensor prediction accuracy. Moreover, the C-TENG was utilized as a self-powered in vitro electrical stimulation device for wound therapy. The C-TENG not only shows excellent potential for future sustainable, self-powered healthcare sensors, but also represents a promising advancement in future wearable wound management systems.

High Thermal Conductive Crystalline Organohalide for Endurable Resistive Switching Non-Volatile Memory.

The organic-based memristive devices are widely studied as a next-generation electronics for eco-friendly wearable applications, thanks to materials` flexibility and biocompatibility. However, poor operational reliability and stability of the devices remain a critical challenge. Here, the study demonstrates a crystalline organohalide, Dabconium ammonium triiodide (DABCO-NH4-I3, DABCO is 1,4-diazabicyclo[2.2.2] octonium)-based memristive device with exceptionally high reliability and endurance. Owing to the low dielectric constant and anisotropic hexagonal crystal structure consisting of hydrogen bonds with a high bandgap, the DABCO-NH4-I3-based conductive bridging random access memory device demonstrates millivolt-scale operating voltages with a remarkably high on/off ratio of ≈109, capable of multi-level storage. The relatively higher thermal conductivity of the crystalline organohalide (1.06Wm-1K-1), compared to most of organic materials (0.1-0.5Wm-1K-1), is found to be beneficial to suppress intense heat accumulation generated by Joule heating effect during device operation. With the facilitated dissipation of the generated heat, the simple planar heterojunction structured device shows remarkably endurable resistive switching over 103 cycles of program-erase at both room temperature and 85 °C with high switching reliability. This study introduced a new class of materials that can overcome the limitations of existing organic materials for high-performance next-generation organic electronic devices.

Vertically aligned liquid metal thermal pad with excellent electromagnetic shielding and ultra-high compressibility

With the increasing integration level of modern electronics, flexible highly thermally conductive and electromagnetic interference shielding (EMI) materials were urgently demanded in electronic devices. Traditionally carbon or solid metal fillers are widely used as a reinforcement to fabricate a flexible thermally conductive and EMI shielding materials. However Due to the trade-off between mechanical and thermal properties, it is difficult to further improve the performance of solid filler/polymer composites. Here in this work based on the intrinsic excellent electrical and thermal conductivity of liquid metal (LM), we embedded the LM network structure vertically in the silicone gel and fabricated a vertically aligned LM(VALM) composites. Compared to the randomly dispersed LM composites, VALM composite exhibits high through plane thermal conductivity (κ⊥: 6.08 W/m·K) and excellent EMI shielding efficiency (SE) (minimum and maximum EMI SE for VALM2 were 33.2 dB and 39.5 dB). In addition, due to the fluidic nature of LM, composite materials exhibit excellent softness and flexibility (compression modulus of 0.56 MPa). Practical heat dissipation test results and EMIS efficiencies demonstrate usefulness of VALM composite in next-generation electronics.

Conductive Hydrogel Materials for Flexible Supercapacitor Electrodes

Flexible supercapacitors (SCs), as promising energy storage devices, have shown great potential for both next-generation wearable electronics and addressing the global energy crisis. Conductive hydrogels (CHs) are suitable electrode materials for flexible SCs on account of their intrinsic characteristics and functional advantages, such as a unique 3D porous structure, remarkable conductivity, tunable chemical and physical properties, and outstanding mechanical properties. Herein, an overview of the fabrication strategies for CHs as electrode materials in flexible SCs, as well as their advantages and disadvantages, and perspectives on CH-based SCs is provided. First, the fabrication strategies for CHs are systematically introduced. Second, various multifunctional CH-based SCs are presented and discussed. Finally, this review concludes with insights into the challenges and opportunities related to CHs or CH-based SCs, indicating future research prospects and application orientations in this field.

Machine Learning Enabled High‐Throughput Screening of 2D Ultrawide Bandgap Semiconductors for Flexible Resistive Materials

AbstractThe 2D ultrawide bandgap (UWBG) semiconductors have attracted great attentions for the next generation of electronics and optoelectronics, owing to their superiority on material flexibility, device stability, and power consumption. However, few 2D UWBG semiconductors have been discovered, impeding their prosperous developments and widespread applications. Here, a high‐throughput workflow is constructed to screen 2D UWBG semiconductors assisted by machine learning, and 507 potential candidates are obtained. Moreover, by learning, predicting, and screening Young's modulus and Poisson's ratio, 31 flexible 2D UWBG semiconductors are identified. Then the generation and the diffusion of anion vacancies, as well as the corresponding electronic properties are investigated by using the first‐principles calculations, and 3 of them are demonstrated as the most promising candidates for the flexible resistive materials. The facile interface tunneling and the increased material conductance caused by the anion vacancies will contribute to the transition from high resistive state to low resistive state. This work provides an efficient high‐throughput screening protocol to enrich the family of 2D UWBG semiconductors and is expected to foster their practical applications.

Local adaptive insulation in amorphous powder cores with low core loss and high DC bias via ultrasonic rheomolding

Amorphous powder cores are promising components for next-generation power electronics. However, they present inherent challenges of internal air gaps and stresses during cold compaction, which significantly deteriorate soft magnetic properties. Here, we report the formation of a local adaptive insulation structure of biconcave lens in amorphous powder cores by ultrasonic rheomolding. Consequently, compared with conventional cold-compacted powder cores, the ultrasonic rheomolded powder cores offer significant simultaneous improvements in the permeability from 31.3–32.4 to 41.8–43.3 and the direct-current bias performance from 69.4–69.7% to 87.4–87.8% (7960 A/m), thereby overcoming the trade-off between permeability and direct-current bias performance. In particular, their core losses are as low as 13.73–15.45 kW/m3, approximately one twentieth of that of the cold-compacted powder cores (282.84–304.03 kW/m3) at a magnetic field of 100 mT and 100 kHz. The biconcave-lens insulation structure can effectively buffer the impact of high mechanical stress on the magnetization of magnetic powder particles, allowing for the ultrasonic rheomolded powder cores to maintain better magnetization efficiency and consequently resulting in excellent soft magnetic properties under the cooperative effect of very low internal stresses and low porosity. The ultrasonic rheomolded powder cores can be used as alternative core components in next generation miniaturized power electronics.

Deep-ultraviolet transparent conducting SrSnO3 via heterostructure design.

Exploration and advancements in ultrawide bandgap (UWBG) semiconductors are pivotal for next-generation high-power electronics and deep-ultraviolet (DUV) optoelectronics. Here, we used a thin heterostructure design to facilitate high conductivity due to the low electron mass and relatively weak electron-phonon coupling, while the atomically thin films ensured high transparency. We used a heterostructure comprising SrSnO3/La:SrSnO3/GdScO3 (110), and applied electrostatic gating, which allow us to effectively separate charge carriers in SrSnO3 from dopants and achieve phonon-limited transport behavior in strain-stabilized tetragonal SrSnO3. This led to a modulation of carrier density from 1018 to 1020 cm-3, with room temperature mobilities ranging from 40 to 140 cm2 V-1 s-1. The phonon-limited mobility, calculated from first principles, closely matched experimental results, suggesting that room temperature mobility could be further increased with higher electron density. In addition, the sample exhibited 85% optical transparency at a 300-nm wavelength. These findings highlight the potential of heterostructure design for transparent UWBG semiconductor applications, especially in DUV regime.

Towards sustainable electronics: High-performance biodegradable polymer-based dielectric composite utilizing hydroxyapatite from cattle bone waste

Polymer-based film capacitors find widespread use in electronics and electrical systems, but the utilization of non-biodegradable dielectric materials contributes to excessive electronic waste. To address this issue, a biodegradable composite of hydroxyapatite (HAp) and poly (butylene adipate-co-terephthalate) (PBAT) was prepared and extensively characterized. HAp, as a filler, was synthesized via biomass-derived bone waste pyrolysis. The analyses confirmed successful HAp synthesis with high crystallinity and well-defined grain boundaries, which promote interfacial polarization and charge storage capability. The composite exhibited remarkable dielectric properties, with high dielectric constant, low dielectric loss, and good breakdown strength at low filler content. The PBAT/HAp-3 % composite showed significant energy storage density improvement (3.56 J/cm3), 43.55 % higher than pure PBAT (2.48 J/cm3), alongside enhanced mechanical properties and thermal stability. This study presents a cost-effective, eco-friendly route for next-generation high-performance disposable electronics.

Single-layer MoS2/graphene-based stable on-chip Zn-ion microbattery for monolithically integrated electronics

Self-powered microelectronics are essential for the sustained and autonomous operations of wireless electronics and microrobots. However, they are challenged by integratable microenergy supplies. Herein, we report a single-layer (SL) MoS2/graphene heterostructure for stable Zn-ion microbatteries. The MoS2/graphene heterostructure not only provides high chemical affinity for Zn and generates perfect lattice matching for Zn (002) deposition, but also facilitates homogeneous current density distribution. As a result, Zn metal is reversibly epitaxially plating/stripping at/from the heterostructure, without the formation of dendrites. The MoS2/graphene-based Zn||MnO2 microbattery with a tiny footprint area sub-0.1 mm2 shows a stable high capacity of 0.16 mAh cm−2 at 0.5 mA cm−2 within 470 cycles. Using a single piece of crystalline MoS2/graphene film, on-chip microbatteries and transistors were simultaneously fabricated via a facile lithography process, achieving highly integrated self-powered field-effect transistors and photodetector. The SL MoS2/graphene-based self-powered monolithically integrated microsystem paves a new way for the multi-functionalization and miniaturization of next-generation electronics.

Thermal Conversion of Ultrathin Nickel Hydroxide for Wide Band Gap 2D Nickel Oxides.

Wide band gap (WBG) semiconductors (E g > 2.0 eV) are integral to the advancement of next-generation electronics, optoelectronics, and power industries owing to their capability for high-temperature operation, high breakdown voltage, and efficient light emission. Enhanced power efficiency and functional performance can be attained through miniaturization, specifically via the integration of device fabrication into a two-dimensional (2D) structure enabled by WBG 2D semiconductors. However, as an essential subgroup of WBG semiconductors, 2D transition metal oxides (TMOs) remain largely underexplored in terms of physical properties and applications in 2D optoelectronic devices, primarily due to the scarcity of sufficiently large 2D crystals. Thus, our goal is to develop synthesis pathways for 2D TMOs possessing large crystal domains (e.g., >10 μm), expanding the 2D TMO family and providing insights for future engineering of 2D TMOs. Here, we demonstrate the synthesis of WBG 2D nickel oxide (NiO) (E g > 2.7 eV) thermally converted from 2D nickel hydroxide (Ni(OH)2) with a lateral domain size larger than 10 μm. Moreover, the conversion process is investigated using various microscopic techniques, such as atomic force microscopy, Raman spectroscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy, providing significant insights into morphology and structural variations under different oxidative conditions. The electronic structure of the converted Ni x O y is further investigated using multiple soft X-ray spectroscopies, such as X-ray absorption and emission spectroscopies.

Multibarrier Collaborative Modulation Devices with Ultra-High Logic Operation Density.

The demands for highly miniaturized and multifunctional electronics are rapidly increasing. As scaling-down processes of transistors are restricted by physical limits, reconfigurable electronics with switchable operation functions for different tasks are developed for higher function integration based on split- or vertical-dual-gate structures. To promote the present reconfigurable electronics and exceed the function integration limit, the critical issue is to integrate complex operations into simple circuit forms by establishing more control dimensions. This work proposes a multibarrier collaborative (MBC) modulation architecture to increase the control dimension by multiple forms of potential barriers and achieves combinational and reconfigurable logic operations by a single MBC device. The MBC architecture exhibits ultrahigh logic operation density, including 58.8% area reduction for multiplexer operations and 71.4% area reduction for 4-logic reconfigurable operations. Besides, a hardware security module composed of 4 MBC devices implementing 8 types of logic operations is demonstrated. This work reveals an effective design of function integration for next-generation electronics.

Quasi-Zero-Dimensional Source/Drain Contact for Fermi-Level Unpinning in a Tungsten Diselenide (WSe2) Transistor: Approaching Schottky-Mott Limit.

Two-dimensional (2D) transition metal dichalcogenides (TMDCs) known for their exceptional electrical and optical properties have emerged as promising channel materials for next-generation electronics. However, as strong Fermi-level pinning (FLP) between the metal and the 2D TMDC material at the source/drain (S/D) contact decides the Schottky barrier height (SBH), the transistor polarity is fixed to a certain type, which remains a challenge for the 2D TMDC field-effect transistors (FETs). Here, a S/D contact structure with a quasi-zero-dimensional (quasi-0D) contact interface, in which the dimensionality reduction effect alleviates FLP, was developed to gain controllability over the polarity of the 2D TMDC FET. As a result, conventional metal contacts on the WSe2 FET showed n-type characteristics due to strong FLP (pinning factor of 0.06) near the conduction band, and the proposed quasi-0D contact enabled by the Ag conductive filament on the WSe2 FET exhibited p-type characteristics with a SBH very close to the Schottky-Mott rule (pinning factor of 0.95). Furthermore, modeling of Schottky barriers of conventional contacts, one-dimensional (1D) contacts, and quasi-0D contacts revealed that the SBH of the quasi-0D contact is relatively less subject to interface dipoles that induce FLP, owing to more rapid decaying of dipole energy. The proposed contact in this study provided a method that progressed beyond the alleviation of FLP to achieve controllable polarity. Moreover, reducing the contact dimensionality to quasi-0D will enable high compatibility with the further scaled-down nanoscale device contact structure.

Self-Charging Zinc-Ion Battery Using a Piezoelectric Separator Immersed in a Hydrogel Electrolyte.

Emerging portable energy systems with integrated sustainability and improved safety have garnered growing interest in wearable electronics. Herein, a self-charging zinc-ion battery is successfully developed by integrating a PVDF-ZnO piezoelectric separator immersed in a quasi-solid-state hydrogel electrolyte (prepared using a 3 m Zn(CF3SO3)2) solution that is sandwiched between a FeVO4 cathode and a zinc anode. This battery effectively captures energy through controlled tapping, eliminating the need for external charging and enabling sustainable energy storage. This self-charging battery can be charged up to 181.23 mV under continuous tapping for 300 s. Upon the cease of tapping, there is a slight decline in the induced potential, which then stabilizes and maintains a consistent potential. Five self-charging batteries connected in series and tapped simultaneously for 300 s generate a potential of 290 mV, whereas five batteries connected in series and tapped one by one induce a potential of 345 mV. This is the first time that a piezoelectric self-charging zinc-ion battery is reported. This study unveils a transformative strategy for realizing next-generation wearable electronics with a self-charging zinc-ion battery design that prioritizes both sustainability and safety.

Elucidating the time-dependent charge neutrality point modulation of polymer-coated graphene field-effect transistors in an ambient environment.

The charge neutrality point (CNP) is one of the essential parameters in the development of graphene field-effect transistors (GFETs). For GFET with an intrinsic graphene channel layer, the CNP is typically near-zero-volt gate voltage, implying that a well-balanced density of electrons and holes exists in the graphene channel layer. Fabricated GFET, however, typically exhibits CNP that is either positively or negatively shifted from the near-zero-volt gate voltage, implying that the graphene channel layer is unintentionally doped, leading to a unipolar GFET transfer characteristic. Furthermore, the CNP is also modulated in time, indicating that charges are dynamically induced in the graphene channel layer. In this work, understanding and mitigating the CNP shift were attempted by introducing passivation layers made of polyvinyl alcohol and polydimethylsiloxane onto the graphene channel layer. The CNP was found to be negatively shifted, recovered back to near-zero-volt gate voltage, and then positively shifted in time. By analyzing the charge density, carrier mobility, and correlation between the CNP and the charge density, it can be concluded that positive CNP shifts can be attributed to the charge trapping at the graphene/SiO2interface. The negative CNP shift, on the other hand, is caused by dipole coupling between dipoles in the polymer layer and carriers on the surface of the graphene layer. By gaining a deeper understanding of the intricate mechanisms governing the CNP shifts, an ambiently stable GFET suitable for next-generation electronics could be realized.

Functionalized cellulose nanocrystals-MoS2 nanosheets to tailor brick–mortar architecture of green composite for next-generation electronic packaging

Thermally conductive green composites are an attractive solution for addressing the escalating heat generation in miniaturized microelectronic devices. They offer simplicity in processing, cost-effectiveness, and the ability to potentially degrade, making them well-suited for overcoming heat-related challenges in next-generation electronics and 5G communication applications. Here, innovative work focuses on developing heat dissipation films by imitating artificial brick–mortar architecture. This approach incorporates cellulose nanocrystals-molybdenum disulfide (CNC-M) nanosheets as bifunctional fillers in polypropylene carbonate (PPC) via straightforward casting technology. This novel composite system leverages CNC-M nanosheets “brick” as oriented bonding and thermal linkers within the PPC “mortar,” significantly enhancing heat transfer across the film, enabling efficient heat propagation and overall thermal conductivity to 3.1 W·m−1·K−1, which is 4450.7 % higher than that of pure PPC. The superior heat dissipation capability enables these composite films to efficiently cool smartphone CPUs, shells, and high-power LED modules. When applying the composite film containing 8 wt% CNC-M to smartphone CPUs and cell phone shells, temperatures decrease by 17.9 °C and 8.3 °C, respectively. Notably, LED modules experience a significant temperature reduction of 22.6 °C. This distinctive “brick–mortar” architecture creates a homogeneous trapezoidal layered architecture that significantly enhances strong hydrogen bonding interactions within a composite film, resulting in exceptional mechanical properties, aging durability, and shape memory. The composite film with 5 wt% CNC-M exhibited impressive increases in tensile strength and Young’s modulus of 152.6 % and 1322.2 %, respectively. Furthermore, the composite film exhibited enhanced UV resistance and based materials. This study advances high-performance thermal conductive materials for electronics thermal management, paving the way for more efficient and sustainable solutions in electronics.