Achieving both high carrier mobility and high luminous efficiency in a single material remains a major challenge in the development of high-performance organic light-emitting transistors (OLETs). Traditional high-mobility materials, such as acene derivatives, often suffer from luminescence quenching because of strong molecular aggregation, whereas highly emissive materials typically exhibit poor charge transport performance. In this paper, we propose a molecular design strategy based on planarization engineering to improve the photoelectric properties of nanogrids and investigate the effect of multi-grid structures on the photoelectric properties. A series of benzo [1,2-b:4,5-b′] dithiophene (BDT)-based nanogrid molecules, including BDTGs, BDTGs-D and BDTGs-T, were designed through the incorporation of benzene rings. Theoretical calculations demonstrate that planarization engineering significantly reduces the hole reorganization energy from 0.122 eV to 0.06 eV and enhances hole mobility to as high as 18.134 cm2V−1 s−1 through improved molecular packing. Further analysis indicates that the proposed structure increases the spontaneous emission rate (2.500 × 108 s−1) relative to the internal conversion rate (9.267 × 107 s−1), thereby enhancing the efficiency of radiative recombination. These results demonstrate that the proposed strategy can simultaneously optimize charge transport and luminescence in OLET materials, providing a promising molecular design approach for next-generation optoelectronic devices.

Out-of-plane polarization in two-dimensional sliding ferroelectrics mainly arises from interfacial charge redistribution and interlayer charge transfer induced by interlayer sliding. However, intrinsic systems generally exhibit weak polarization and face intrinsic challenges in incorporating magnetism. In this work, BN/BN homostructures and Gr/BN heterostructures are used as representative models to investigate how B, N, and C vacancy defects modulate charge transfer, out-of-plane polarization, and magnetism in bilayer and trilayer stacked structures. The results show that vacancy defects break the symmetry of the interfacial charge distribution and enhance interlayer charge transfer, thereby substantially amplifying the out-of-plane polar response. In trilayer structures, a defective middle layer induces a cumulative two-step charge-transfer mechanism, enabling BN/VN@BN/BN to exhibit two oppositely polarized states of approximately +5.5 and − 5.5 pC/m. This polarization enhancement exceeds that of the intrinsic trilayer structure and cannot be described as a simple superposition of the corresponding bilayer contributions. Minimum-energy-path calculations reveal that BN/VN@BN/BN and Gr/VN@BN/Gr can undergo continuous polarization reversal through cooperative interlayer sliding, with energy barriers of approximately 9 and 14.5 meV/u.c., respectively. Meanwhile, both classes of systems exhibit the coexistence of polarity and magnetism characteristic of type-I multiferroics. The former is half-metallic, whereas the latter is metallic; however, the magnetoelectric coupling remains weak. A high-concentration vacancy model is adopted in this work, and the results primarily elucidate the fundamental mechanisms by which vacancy defects enhance sliding-induced polarization and induce polar-magnetic coexistence, thereby providing theoretical guidance for the design of experimentally accessible two-dimensional systems.

This research introduces a two-dimensional compound, AlGaP₂, which retains its structural integrity under both room and elevated temperatures. Investigations into its mechanical characteristics indicate that AlGaP₂ has an exceptionally low Young's modulus in the y-direction, granting it remarkable flexibility. Notably, the material displays a significant negative Poisson’s ratio of −1.80 in the 23.5° direction, ranking it among the highest for two-dimensional auxetic substances. This unique property arises from alterations in bonding characteristics due to charge transfer during tensile stress. Additionally, calculations of its optical properties reveal that AlGaP₂ possesses high optical absorption efficiency and appropriate band-edge positions for water splitting, making it a promising candidate for photocatalytic applications in clean energy generation.

The auxetic behavior in nanostructures has attracted considerable attention due to their wide potential applications. Due to the long-standing attribution of auxetic properties to the unique geometric structure of materials, the academic community's understanding of auxeticity is not profound. It is considered to have no access to tuning the auxeticity without phase transition. In this letter, an anomalous case is discovered where the auxetic transition is directly driven by the electronic correlation in Janus-Tetra-SiXY (JT-SiXY; X, Y = O, S, Se) lattice. The auxeticity is highly dependent on the electronic properties. Additionally, the auxeticity is significantly enhanced due to the Janus modification. The emerging auxetic transition effect and enhanced auxeticity would make JT-SiXY a promising candidate in two-dimensional nano-devices. Our study provides valuable clues and useful guidance for designing advanced auxetic materials.

The intrinsic auxeticity of materials has long been attributed to their unique geometric configurations. Triggering and enhancing auxeticity presents significant challenges, as many nanomaterials display subtle auxetic effects with a negative Poisson's ratio (NPR) typically above -0.4. This paper introduces three materials with identical symmetry—two-dimensional pentagonal structures Penta-B2X2Y2 (i.e., Penta-B2C4, Penta-B2N4, and JP-B2C2N2)—to investigate a novel mechanism influencing material auxeticity: electron transfer. Specifically, variations in electron transfer cause Penta-B2N4 and JP-B2C2N2 to show axial auxetic effects, whereas Penta-B2C4 demonstrates opposite behavior. The axial NPR of Penta-B2N4 is ~ -0.05, while for JP-B2C2N2, it reaches ~-0.46, significantly surpassing that of typical intrinsic auxetic materials. This represents an increase of approximately 920% compared to Penta-B2N4. Additionally, JP-B2C2N2 features semi-metallic properties, where the conduction band minimum (CBM) and the valence band maximum (VBM) are tangent to the Fermi level. Consequently, minor alterations in external conditions can induce a transition between semiconductor and metallic states in JP-B2C2N2. Thus, the 2D material JP-B2C2N2 emerges as a promising candidate for nanoelectronic and electromechanical applications. Furthermore, this study also enhances the academic understanding of auxetic properties in nanomaterials by linking their mechanical and electronic characteristics and laying a theoretical foundation for further experimental exploration of auxeticity.

Layered auxetic materials have an acute demand for the in-plane negative Poisson's ratio (NPR) due to dimensional restrictions. Yet, it is not yet apparent and developed where the auxeticity in nanomaterials origins from. Aimed at inserting in-plane auxeticity, in this letter, we theoretically propose a series of Si2O-based layer-stacking materials using a bottom-up strategy. As a result of the materials' chemical O absorption, which causes the Pauli repulsion of inter-layer orbits to shift in the direction of the plane, a newly found multi-directional NPR effect is finally realized in II-BK-Si2O. Furthermore, the multilayer structures preserve dispersion of the SL-Si2O while breaking the semi-Dirac semi-metallic conditions and gapped, endowing the materials semiconducting characteristics and strong carrier mobilities. For Si2O-based materials, the aforementioned benefits open up a wide range of application possibilities and research potential.

Carbon-based materials that process a wide bandgap, high mechanical performance, thermal stability and adjustable characteristics are in high demand.

Atomically thin two-dimensional (2D) crystals have piqued the curiosity of researchers due to their unique features and potential applications, such as catalysis and ion batteries. One essential and desirable aspect of 2D materials is that they have a large photoreactive contact surface for optical absorption. Here, a 2D crystal is proposed that possesses a moderate adjustable indirect band gap of 1.95 eV (HSE06) and exhibits ultrahigh visible light harvesting with a absorption coefficient of up to 108 cm-1 in the ∼380 to 800 nm range of the visible light spectrum. Besides that, the indirect band gap can be converted to a direct one under biaxial strain. By means of density functional theory, the 2D Al2Te5 monolayer displays great stability and promise of experimental fabrication. These advantages will provide considerable application potential for future photovoltaics (PV) devices.

The energy storage device has been urgently studied and developed to meet the increasing demand for energy and sustainable development.Due to the excellent conductivity of graphene and high perfor-mance of ZnCo2O4 and NiCo2O4,we design a self-supporting electrode based on vertically grown two-dimensional/two-dimensional(2D/2D)NiCo2O4/ZnCo2O4 hierarchical flakes on the carbon-based conduc-tive substrate(NiCo2O4/ZnCo2O4@graphene/carbon nanotubes,NZ@GC).The density functional theory cal-culations indicate that the high OH-adsorption capacity of the NiCo2O4/ZnCo2O4 nanosheets can signif-icantly enhance the electrochemical reaction activity.NZ@GC shows a high capacitance of 1128.6 F g-1 at 1 A g-1.The capacitance retains 84.0％after 6000 cycles even at 10 A g-1.A hybrid supercapacitor is fabricated using NZ@GC and activated carbon,exhibiting a large energy density of 50.8 W h kg-1 at the power density of 800 W kg-1.After 9000 charge/discharge cycles,the supercapacitor still has 86.1％ca-pacitance retention.The NZ@GC film has showed the potential as promising electrodes in high efficiency electrochemical energy storage devices.

The purpose of this study is to investigate the solid solution strengthening (SSS) of Sn, Pb in aluminum (Al) matrix under high current pulses electron beam (HCPEB) irradiation. First-principles calculations method was adopted to quantify the effect of SSS with various concentrations. The capacity to strengthen is correlated with a nearly linear concentration dependency. In experimental section, the microstructures of the Pb/ and Sn/Al systems were characterized by SEM and TEM analysis. The solubility limit of both systems under HCPEB irradiation were calculated by a simple thermodynamic model. It is found that the Sn/Al system has a higher solid solubility, compared to that of the Pb/Al. In addition, the values of SSS of the Pb/ and Sn/Al systems were estimated. The results show that the Sn/Al system has higher strengthening ability than that of the Pb/Al system under HCPEB irradiation due to the different solid solubility, which is consistent with theory.