Hydrogen incorporation strongly affects carrier density and reliability in oxide semiconductors, yet its behavior in the crystalline indium–aluminum–zinc oxide has not been fully established. Using first-principles calculations, stable hydrogen incorporation sites and their migration characteristics were systematically examined. Hydrogen preferentially occupies oxygen atoms coordinated by three zinc atoms, which remain stable against dissociation with barriers exceeding 0.5 eV. In contrast to the crystalline indium–gallium–zinc oxide, where gallium and zinc readily intermix, the crystalline indium–aluminum–zinc oxide contains a distinct planar aluminum–oxygen layer that acts as a vertical diffusion barrier. Penetration across this dense hexagonal layer requires hydroxyl rotation rather than conventional dissociation–migration, leading to substantially higher activation energies. The combination of site selectivity and anisotropic migration enables confinement of hydrogen dopants within a sub-unit cell thickness, providing a pathway to localized conductivity enhancement while maintaining the wide bandgap and low carrier density of the bulk material.

Weyl phononic crystals (PCs), as a key platform for topological states, feature doubly degenerate Weyl points of band structures in three-dimensional (3D) space. Their investigation has expanded from electronic systems to classical waves, including electromagnetic, acoustic, and elastic waves, and has drawn extensive attention. However, elastic wave systems are limited by fixed structures, making the active modulation of topological surface states challenging. To overcome these limitations, we design a tunable 3D Weyl magnetoelastic PC composed of magnetostrictive materials integrated with an elastic substrate. Based on the magneto-mechanical–thermal coupled constitutive relation of magnetostrictive materials, we have achieved the spatial inversion symmetry breaking under the collaborative regulation of magnetic and thermal fields, and observed the elastic wave Weyl points and their frequency-tunable characteristics. We further examine the robust transport of Weyl surface states under waveguide and defect conditions, as well as layer-selective transmission achieved through boundary condition design. This work provides a new route for dynamic regulation of elastic wave topological transport and offers significant potential for the development of customizable topological devices.

Two-dimensional (2D) lateral superlattice is a promising route to tailor thermoelectric properties, yet the impact of superlattice period length on the modulation of phonon and electronic transport remains insufficiently characterized. Using a monolayer CrS2/CrSe2 superlattice as a model system, we combine density-functional theory with a machine-learning potential to quantify the period-dependent thermoelectric properties. Due to the reduced phonon group velocities and shortened phonon lifetimes, our calculation results reveal that the room-temperature lattice thermal conductivity (κp) of short-period superlattice (SS) and long-period superlattice (LS) structures along the modulation direction is reduced by 71.3% and 82.9%, respectively, compared with that of the pristine CrS2. Moreover, the interface-induced charge redistribution in LS disrupts electronic transport continuity, suppressing electrical conductivity (σ). By contrast, SS retains more extended charge states while maintaining σ with reduced κp. As a result, the ZT value of SS (∼0.39) is higher than that of LS (∼0.21) at 600 K, despite LS having a lower κp. This work emphasizes the importance of co-optimizing phonon and electronic transport in superlattice structures by tuning the superlattice period, providing engineering strategies for designing 2D superlattice thermoelectric materials.

The recent successful fabrication of single- and multi-layer gold, referred to as goldene, represents a significant breakthrough in low-dimensional materials research. A fundamental understanding of its phonon transport properties, both intrinsic and extrinsic, is crucial for assessing its potential in applications such as thermal management, sensing, solar cells, and photothermal therapy. Here, we perform extensive machine-learning molecular dynamics simulations using an accurate and efficient unified neuroevolution potential to investigate the intrinsic lattice thermal conductivity of goldene and its tunability through external strain, defects, and layer thickness, drawing close comparisons with bulk gold. We find that single-layer goldene exhibits a high intrinsic lattice thermal conductivity of 34.4±0.4Wm−1K−1, which is approximately 17 times as large as that of bulk gold. While both systems exhibit a κ∼T−p dependence (p=1.69 for goldene, p=1.30 for bulk), they respond oppositely to tensile strain: κ decreases in bulk gold but increases in goldene. We attribute this contrasting behavior to the fundamentally different effects of strain on their phonon modes, hardening the dominant flexural phonons in goldene while softening all the phonon modes in bulk gold. Furthermore, both vacancy and adatom defects significantly reduce κ, with adatoms having a more pronounced effect. Finally, κ decreases monotonically with increasing layer number, rapidly converging toward the bulk value. Our results elucidate the intrinsic lattice thermal transport in goldene and demonstrate versatile strategies for tuning it, thereby enriching the understanding of heat transport in two-dimensional metallic systems.

Due to the hysteresis phenomenon of ferromagnetic materials, an unknown remanence BR will be generated after the material is disconnected from the power supply, which can cause a considerable inrush current, so that the safety of electrical equipment can be seriously affected. Therefore, various methodologies for evaluating the remanence have been proposed to achieve more effective demagnetization of ferromagnetic materials. However, the proposed remanence evaluation only applies in certain exceptional cases due to the lack of physical significance. In this study, based on the maximum irreversible differential magnetization [max(dMirr/dH), MIDM], a new remanence evaluation method is proposed. First, based on the Jiles-Atherton (J–A) hysteresis theory, a relationship between the MIDM and the remanence is investigated. Then, hysteresis loops under the different remanence are used to obtain the MIDM for the remanence estimation in practice. Finally, an experimental platform based on the Epstein frame is used to examine the reliability of this approach. The obtained results indicate that the proposed method has an error range of 2.72%–9.67% in experiments. This study provides a new theoretical basis for the remanence evaluation, which has essential scientific theoretical significance.

During the fabrication of heterogeneous structures inside chips, impurities and defects are inevitably introduced. However, the mechanism by which defects affect interfacial heat transport remains unclear. This work proposes a heterostructure thermal transport model that incorporates the effects of defects. The Boltzmann transport equation is solved using the Monte Carlo simulation, with full-band phonon properties obtained from first-principles calculations serving as input parameters. The effects of defect concentration and location on thermal transport characteristics are investigated for four heterointerfaces: Si/SiC, GaN/SiC, Si/diamond, and GaN/diamond. Temperature distribution, spectral thermal conductance, average phonon scattering numbers, and interfacial thermal conductance (ITC) are compared under different conditions. The results show that, for Si/SiC, Si/diamond, and GaN/diamond interfaces, introducing defects weakens heat transport. Higher defect concentration leads to lower ITC. Furthermore, when defects are in SiC or diamond, which have broader phonon spectral distributions, their impact on ITC is weaker. For the GaN/SiC interface, defects in GaN reduce ITC, while defects in SiC enhance ITC. At a defect concentration of 0.56%, ITC decreases by 54.1% when defects are present in GaN, but increases by 57.2% when defects are in SiC. This behavior arises from defect-induced phonon energy redistribution near the interface. The redistribution increases the population of low-frequency phonons, which are more capable of crossing the interface, thus enhancing interfacial heat transfer. However, although introducing defects can increase ITC, it also raises the bulk thermal resistance, leading to a higher total thermal resistance of the heterostructure. It remains challenging to enhance heat transfer across heterostructures by defect engineering. This study enriches the fundamental understanding of thermal transport across semiconductor heterointerfaces and guides the design and fabrication of high heat-transfer heterostructures.

In this study, we investigated the structural properties of In1−xScxN thin films and studied their phase evolution and lattice behavior across varying Sc concentrations. XRD analysis was employed to determine the phase stability and to identify the critical composition range when the transition from wurtzite to cubic structure occurs. The corresponding changes in lattice parameters were quantified by calculating a and c. Optical transmission measurements combined with absorption coefficient analysis and Moss–Burstein corrections enabled the estimation of the optical bandgap, which exhibited a systematic blue shift in the wurtzite phase with increasing Sc content. Our findings lay a crucial groundwork for deeper exploration of this novel material system and seek to inspire wider research into its potential for different application fields.

Measurement of low power infrared light emission spectra from microstructures can be challenging but is of key importance in several research fields. Fourier transform infrared (FTIR) spectrometers can be used for characterizing such weak light emitters, but this requires additional custom user calibration compared to traditional FTIR measurements of, e.g., transmission or reflection. These calibration techniques are well documented for standalone FTIR instruments but not for microscope-coupled FTIRs, even though such an architecture greatly simplifies the collection of light from micro- and nanoscale structures. We propose and demonstrate a calibration method for microscope-FTIRs based on the well-known emissivity of doped silicon at high temperatures. With this method, we measure the responsivity and noise floor of a recently installed microscope-FTIR instrument (Bruker© Invenio® R coupled with a Hyperion II microscope), which is found to be within theoretically predicted values. The method is demonstrated for two different detectors (mercury cadmium telluride and indium antimonide), in both continuous wave and modulated (step-scan) emission measurement modes.

1/f noise analysis is a powerful tool for characterizing defects in the bulk of the gate oxide of metal oxide semiconductor field effect transistors (MOSFETs). The bulk trap density (NBT) is often extracted from the commonly used carrier number fluctuation model. This model fits well with thicker gate oxide devices but does not capture the effect of oxide scaling on the 1/f noise. As a result, it yields an error of several orders of magnitude in estimating NBT in the scaled devices. In this work, we derive a compact expression of drain current noise power spectral density (SID) that accurately estimates NBT for scaled devices. Our expression includes terms that account for the position dependence of traps, which is often neglected in previous studies. We validate the robustness of the model by comparing it with the calibrated technology computer-aided design simulations of the advanced 22 nm ultrathin body and buried oxide fully depleted silicon-on-insulator MOSFET device operating in linear, saturation, and subthreshold regions.