ACS Applied Electronic Materials最新文献

For the advancement of next-generation nanoscale technologies, two-dimensional (2D) materials have generated significant interest. However, the low carrier mobility in nanoscale devices greatly hinders their development. Recently, the Janus 2D B₂P₆ has been predicted, combining anisotropic electronic transport with high electron mobility. Here, first-principles computations are used to examine the structure, electrical properties, and carrier mobility of bilayer B₂P₆ in various stacking configurations. The results show that B₂P₆/B₂P₆ stacking with type-II band alignment is the most stable configuration among the four bilayer B₂P₆ modes. Importantly, the band gap of bilayer B₂P₆ can be regulated from 1.24 to 0.08 eV by changing the stacking modes and interlayer distance and applying biaxial strain. The dipole moment of bilayer B₂P₆/B₂P₆ increases in the Z-direction, resulting in a high dipole moment of 0.353 e·Å, which is positively correlated with the increase in the electrostatic potential difference. Furthermore, the electron mobility in bilayer B₂P₆ exhibits triple enhancement compared to the monolayer, reaching 15442.45 cm² V^–1 s^–1 in the x-direction. It is confirmed that the deformation potential and elastic moduli play major roles in determining the carrier mobility. Thus, the bilayer Janus B₂P₆ exhibits significant potential for next-generation electronic devices.

Different from diphenylamine-based organoboron multiresonance (MR) emitters with blue-to-green emissions, this work presents the design and preparation of two boron and nitrogen-containing MR-TADF compounds (BDQuAc and BDSpQuAc) based on methylene and spirofluorene-bridged N-phenylphenazine ligands for efficient yellow narrowband organic light-emitting diodes (OLEDs). N-Phenylphenazine ligands with their strong electron-donating ability promote a short-range charge transfer (CT) effect within the MR skeleton, leading to red-shifted emission in toluene with peaks at 534–537 nm. The suppression of molecular rotation by the methylene and spirofluorene bridges results in a narrow emission spectrum, with a full width at half-maximum (fwhm) of only 0.16 eV. Concurrently, the enhanced molecular rigidity contributes to high photoluminescence quantum yields (PLQYs) of 90–95%. Meanwhile, compared to BDQuAc with a methylene bridge, BDSpQuAc based on a spirofluorene bridge exhibits weaker intermolecular aggregation with less dependence of photoluminescent spectra on doping level. The solution-processed OLED device incorporating BDSpQuAc demonstrates high-performance yellow emission with a peak at 559 nm, CIE coordinate values of (0.45, 0.54), and a maximum external quantum efficiency (EQE_max) of 17.9%, representing efficient yellow-emitting narrowband OLEDs by solution processing.

As DRAM technology nodes move into the sub-10 nm regime, capacitor scaling is increasingly constrained by both footprint loss and a hard physical thickness limit for the entire electrode–dielectric–electrode stack. Under these conditions, the long-standing TiN/ZrO₂/TiN platform approaches a point where further equivalent oxide thickness (EOT) reduction would require ultrathin dielectrics with unacceptable leakage. Rutile TiO₂ is attractive as a post-ZrO₂ dielectric because its intrinsically high permittivity can, in principle, deliver sub-0.3 nm EOT at practical thicknesses while retaining process simplicity as a binary oxide and leveraging the broad atomic layer deposition (ALD) precursor availability. The crucial barrier is manufacturable rutile stabilization within the DRAM thermal budget, especially on industry-standard TiN, together with leakage suppression in TiO₂ with a small band gap and intrinsic n-type nature. This Spotlight highlights integration-driven pathways for low-temperature rutile stabilization, spanning templated growth on rutile-compatible conductive oxides and nontemplated strategies on TiN and then discusses leakage control through electrode choice, interlayer band engineering, and defect and dopant management. We close by outlining the key process and materials milestones required to translate rutile TiO₂ from a promising concept into a scalable DRAM dielectric platform.

Bismuth ferrite (BiFeO₃, BFO) is a p-type multiferroic oxide with tunable defect chemistry, offering significant potential for gas sensing applications. Here, we report a cost-effective synthesis procedure of BFO nanoparticles via a hydrazine-assisted sonochemical synthesis method, which yields predominantly phase-pure perovskite BFO (>90%) with minor Bi₂Fe₄O₉ impurities. TEM analysis revealed an average particle size distribution of ∼80 nm; however, acetone sensing was strong and reproducible, which indicates that the collective nanoparticle ensemble governs performance. XPS analysis confirmed that iron is exclusively present in the Fe³⁺ oxidation state and revealed a high concentration of surface oxygen vacancies. These vacancies act as active adsorption sites and facilitate the formation of reactive oxygen ions, driving the p-type response to acetone at concentrations as low as 1 ppm. The sensors demonstrated high sensitivity, rapid response and recovery, excellent selectivity over different kinds of interfering gases, and stable operation. These results underscore the crucial role of defect engineering and cost-effective synthesis in enabling efficient BFO-based acetone sensors for breath analysis and environmental monitoring.

As biocompatible soft materials with stimuli-responsive characteristics, wearable strain sensors based on conductive hydrogels hold substantial promise across diverse engineering fields. However, their practical applications are often hindered by limited sensitivity and issues related to single functionality. This study presents a multifunctional composite hydrogel composed of PAA/PVA/PEDOT:PSS/Ti₃C₂T_X designed for flexible strain sensors and synthesized through a straightforward one-pot polymerization technique. The incorporation of Ti₃C₂T_X MXene nanosheets significantly enhances the porous architecture and mechanical properties of the hydrogel. This hydrogel features a combination of covalent and physical cross-linking networks, showcasing remarkable elastic recovery, puncture resistance, stretchability, robust interfacial adhesion, and self-healing capabilities. The hydrogel-based strain sensor demonstrates exceptional performance, including high sensitivity (GF = 21.36 in the 31–50% strain range), a low detection limit (53.0 Pa), rapid response and recovery times (42 ms/38 ms), and long-term stability (>1,600 cycles). Its practical applications in information encryption, handwriting recognition, and wireless robotic motion monitoring highlight its potential as a versatile platform for advanced flexible sensing technologies.

The rising demand for high-performance integrated circuits for artificial intelligence (AI) is pushing conventional silicon transistors to their physical limits, prompting the search for alternative semiconductor materials. Oxide semiconductors (OS), with wide band gap, ultralow leakage, high mobility, and low thermal budget, offer appealing advantages for logic, dynamic random-access memory (DRAM), and monolithic 3D (M3D) integration in the post-Moore era. While tremendous progress has been made in the past decade in this field, several key challenges in terms of materials, devices, and process integration remain to be addressed. In this work, we discuss the critical issues in mobility, threshold voltage, reliability, and scalability and evaluate different strategies such as composition tuning, defect and interface engineering, and doping to enhance the device performance. We further discuss the potential and limitations of the OS in their applications in logic, DRAM, and M3D integration. Looking forward, a holistic cooptimization across materials, devices, and processes, combined with AI computing architectures, is expected in order to realize reliable, low power, high-mobility integrated circuits for next-generation intelligent chips.

Flexible strain sensors have attracted much attention for their immense application potential in fields such as health monitoring, human–machine interaction, and sports science. However, the inherent coupling constraints between core sensing parameters (sensitivity, working range, and stability) lead to severe challenges in multiperformance collaborative improvement, which seriously restricts the large-scale promotion of sensors in various scenarios. Herein, a design strategy of heterogeneous conductive network structure with functional partition is proposed to resolve the challenges. The flexible strain sensor with linear and multiring carbon-based (C) conductive networks in series is prepared on thermoplastic polyurethane (TPU) substrate by screen printing. The linear pathways function as a sensitive unit to achieve strain concentration and rapid crack response, while the interconnected multiring pathways act as a buffer unit dissipating strain energy through elastic deformation. This structurally engineered C/TPU sensor successfully reconciles the performance trade-off, demonstrating an ultrawide sensing range (up to 128% strain), high sensitivity (GF up to 56857) and excellent stability (over 8000 cycles). The flexible C/TPU sensor with outstanding comprehensive performance can capture and quantify full-range human biomechanical signals with high fidelity. Moreover, high-precision recognition of complex knee joint motion patterns (average accuracy up to 98%) is achieved with the support of artificial intelligence. The theoretical and ingenious structure engineering design strategy proposed in this study provides a feasible approach for performance synergistic optimization of flexible strain sensors, which is of great significance for advancing the development in smart wearable devices.

With the rapid development of wearable electronic devices, there is an increasing demand for high-performance flexible strain sensors. In this study, LM/CNT composite ink was prepared by the ultrasonic dispersion method, and the electron transfer between carbon nanotube (CNT) and liquid metal (LM) was utilized to construct a three-dimensional conductive network, which effectively enhanced the wettability and conductivity of the ink and the tensile performance of the sensor. Flexible strain sensors were prepared based on LM/CNT conductive ink, and the effects of different electrode patterns on sensor performance were explored. The stress distribution of linear (P I), folded (P II), and serpentine (P III) electrode patterns under tensile conditions was systematically investigated by theoretical analysis of material mechanics and finite element simulation. The experimental results show that the P III type has the smallest stress concentration and the highest sensitivity under various strains. In addition, the P I type sensors have the function of direction recognition due to their different responses to anisotropic deformations. Based on the P I type sensor, we successfully prepared a triboelectric nanogenerator (TENG) and demonstrated its potential application in the field of digital recognition by utilizing its friction power generation and orientation recognition properties.

Solar-blind ultraviolet (SBUV) photodetectors are in high demand for applications such as missile warning, flame sensing, and non-line-of-sight communication. However, the development of detectors that simultaneously possess high sensitivity, low power consumption, and a fast response speed remains a challenge. This work demonstrates the epitaxial growth of high-quality, 1 μm-thick gallium oxide (Ga₂O₃) films on strontium titanate (SrTiO₃ or STO) (001) single-crystal substrates via magnetron sputtering for constructing metal–semiconductor–metal (MSM) SBUV photodetectors. The device exhibits outstanding comprehensive performance at a low operating voltage of 5 V: a responsivity of 0.22 A/W and a corresponding detectivity of 1.91 × 10¹³ Jones, indicating an excellent capability for weak light signal detection. Simultaneously, under a 1 V bias, it demonstrates an extremely low dark current of 2.1 × 10^–12 A and a high photo-to-dark current ratio (PDCR) of ∼10⁵, which significantly improves the signal-to-noise ratio and anti-interference capability. Furthermore, the device exhibits clear fast switching characteristics with rise and fall times of 48.06 and 9.12 ms, respectively. These results indicate that Ga₂O₃ films epitaxially grown on STO substrates constitute an ideal material system for constructing high-performance, low-power-consumption SBUV photodetectors, showing great application potential in next-generation optoelectronic devices.