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In this policy brief, Antonia Hmaidi, Senior Analyst in the Science, Technology and Innovation Program at MERICS, analyzes Huawei, a company that is emerging as the leader of China’s national team in semiconductors, dominating chip manufacturing and seeking to integrate the country’s entire supply chain. Its ambitions stem from both its placement on the U.S. Entity List and strong government support at the national and local level. Internationally, Huawei is coy about these ambitions, hiding its supply chain involvement and often operating under a different company’s name. Meanwhile, Huawei’s experience is also encouraging other Chinese technology companies to support China’s quest for chip self-sufficiency, developing new hardware and software for that purpose. The clandestine nature of Huawei’s involvement—it is not known who serves what role in semiconductor production—makes it more difficult for Western companies and governments to assess China’s progress in technology, vet potential partners and customers, and conduct risk assessments.

Ni 1 − x TixMnSb polycrystalline alloys in the range 0 ≤ x ≤ 0. 2 0 were synthesized employing the standard solid-phase synthesis method. The crystal, magnetic, as well as electrical properties of the alloys were investigated using neutron powder diffraction and magneto-resistance measurements. The results reveal that the substitution of Ti for Ni within the temperature range of 2.5–300 K does not induce alterations in the crystal and magnetic structures of NiMnSb. The ordered Ni magnetic moment approaches zero. The study of the electrical transport properties of the Ni 1 − x TixMnSb alloys, where 0 ≤ x ≤ 0. 2 0 , has demonstrated a half-metallic state at low temperatures and metallic conductivity for temperatures exceeding 160 K. A semiconductor state manifests at titanium concentrations of x = 0.2 and was observed at temperatures below 21 K. The obtained experimental results are elucidated through first-principles theoretical calculations. [ABSTRACT FROM AUTHOR]

AbstractThe article explores the photothermal interactions occurring in a semiconducting semi-infinite half-space with axisymmetric characteristics. The study is situated within the framework of a fully coupled system of generalized thermoelastic theory for semiconductor media. The bounding surface is traction-free, subjected to a prescribed axisymmetric temperature distribution, and governed by a zero-flux condition. Employing an integral transform technique, the solution is derived, and Laplace transform inversions are carried out using the Gaver-Stehfest numerical scheme. The mathematical model is specifically tailored for Silicon material, and the ensuing numerical results are meticulously discussed and presented graphically. [ABSTRACT FROM AUTHOR]

This study investigates the contemporary thermoelasticity theories in a photothermal semiconducting medium with voids influenced by the electromagnetic field. Boundary conditions of the phenomenon were based on the equations that regulate it concerning the stresses, carrier density, change in volume fraction field and temperature on the surface space. The equations were solved in normal mode technique, and the results are displayed by graphs. A comparison has been made with the findings of the literature when neglecting the new external parameters. The findings show that the presence or absence of electromagnetic field and carrier density significantly impacts on the phenomenon. From the results obtained, it is clear that the effects of electromagnetic field, carrier density, volume fraction and thermal relaxation times are very pronounced and applicable in diverse fields including geophysics, astronomy, engineering, biology, etc. [ABSTRACT FROM AUTHOR]

Cu2SnS3 (CTS) is expected to be an absorber material for next-generation solar cells because it is composed of nontoxic, low-cost elements and has an absorption coefficient of >104 cm−1. In this study, the effects of sulfurization in tin sulfide (Sn x S y) and S mixed vapors on various properties of CTS were investigated by using a 3-zone tube furnace to suppress carrier recombination at the grain boundaries and control the composition of the CTS. The CTS deposited via sulfurization in S vapor only (1-zone CTS) contained different monoclinic and tetragonal CTS structures. The grain size of the CTS thin films deposited via sulfurization in Sn x S y and S mixed vapors was not increased. On the other hand, crystal structure analysis revealed that the CTS had grown to single-phase monoclinic CTS. The results suggest that precipitation in Sn x S y and S mixed vapors contributes to the growth of monoclinic CTS with suitable power-generation characteristics. This finding is important for realizing high-efficiency CTS-based solar cells. [ABSTRACT FROM AUTHOR]

Understanding the electronic structures of gate oxides in Si-based devices is significant for improving device performance. We investigate the electronic properties of the oxygen vacancy defects in β -quartz SiO2/Si interface structure using first-principles calculations. The results indicate that the constructed (SiO2)4/(Si)4 structure is an indirect-gap semiconductor, with its band edges contributed by Si side and a large band-edge energy difference ( > 1.780 eV). Our study reveals that the presence of oxygen vacancy defects reduces the band gap, and V O 1 is transformed from indirect into direct band gap. The Si dangling bonds in V O 1 cause charge localization around the O vacancy, while the formation of Si–Si bonds in V O 2 and V O 3 lead to electron delocalization. In the calculation of defect formation energies, we find that V O 1 maintains the lowest formation energy across different states, making it more likely to form and structurally stable. Compared to O-rich environments, the formation energy in O-poor environments is overall reduced by approximately 4.5 eV, indicating that oxygen vacancy defects are more likely to form and be controlled under O-poor conditions. Our study emphasizes the importance of interface structure and defect characteristics in semiconductor research, providing insights for the development of Si-based devices. [ABSTRACT FROM AUTHOR]

Context: A significant class of solid-state materials, Ruddlesden–Popper (RP) perovskites are well-known for their rich chemical compositions that make them excellent electrocatalysts. Therefore, in this work, we conduct thorough analysis of RP perovskites, specifically Ca2XO4 (X = Zr, Hf). We delve into the structural, electronic, optical, and mechanical properties presenting their insights for the first time. Our investigations reveal that Ca2XO4 (X = Zr, Hf) exhibits stable tetragonal phase structures, with energies (E0) of − 10,522.93 eV and − 33,520.14 eV, respectively. The calculated E cohsive / atom in terms of the ground state determines to possess distinct values such as − 4.79 eV/atom for LiScTe2 and − 3.95 eV/atom for Ca2ZrO4 and Ca2HfO4. Notably, the semiconductor characteristics of Ca2ZrO4 and Ca2HfO4 are underscored by their respective wide direct band gap of 5.02 eV and 5.30 eV. Then, we discuss the optical parameters encompassing the dielectric function, absorption coefficient, optical conductivity, refractive index, and energy loss function. Ca 2 ZrO 4 is described as ductile, whereas Ca 2 HfO 4 is defined as brittle. Our outcomes underscore remarkable ability of these materials to absorb ultraviolet radiation from the electromagnetic spectrum, positioning them as promising candidates for optoelectronic applications. Methods: We made these calculations by employing first-principles approach rooted in density functional theory (DFT) and utilizing the Perdew-Burke-Ernzerhof-Generalized Gradient Approximation (PBE-GGA) and Tran and Blaha-modified Becke–Johnson (TB–mBJ) functional within the WEIN2K framework. In this framework, Kramers–Kronig relations are used to obtain crucial optical parameters. Mechanical behavior is assessed by employing Voigt-Reuss-Hill approximation (VRH) fulfilling the Born's criteria which emphasizes that these materials are equally appropriate for a broad range of mechanical applications. [ABSTRACT FROM AUTHOR]

This study introduces a generalized photothermal model to analyze the coupled thermo-hydromechanical behavior of a poroelastic, nonlocal semiconductor medium subjected to laser excitation. The medium is modeled as a saturated, dynamic, poroelastic half-space under time-harmonic loads, including thermal and mechanical forces and plasma electron distribution induced by laser pulses. A novel framework that integrates photo-thermoelasticity with hydrodynamic and poroelastic effects, capturing the nonlocal interactions at the nanoscale. At first, we subjected this medium to time-harmonic loads comprising thermal and normal loads and a distribution of plasma electrons applied with heating laser pulses. Afterward, we compared the photo-thermoelastic dynamic models to the coupled thermo-hydromechanical ones. The resulting nondimensional coupled equations were solved using two-dimensional normal mode analysis. The resulting nondimensional coupled equations were solved using two-dimensional normal mode analysis. The study examined the effects of nondimensional displacement, mechanical stress, excess pore water pressure, carrier concentration (density), and temperature distribution on the poroelastic half-space medium. Graphical representations were produced to highlight these effects based on specific parameters. [ABSTRACT FROM AUTHOR]

Herein, CdTe/MnS core/shell nanoparticles dispersed in an aqueous solution have been synthesized. The formation of MnS semiconductor shell occurs by spontaneous self‐assembly. This process is activated by thermal hydrolysis that removes the excess of thiol and releases S2− ions. In this process, Mn2+ ions on the surface of the CdTe nanoparticles bind to S2− ions to produce a fine semiconducting layer of MnS. Measurements of Raman spectroscopy, optical absorption, and electrochemical measurements are performed. The Raman spectrum shows CdTe characteristic bands at 141 and 163 cm−1. Bands at 221 and 444 cm−1 are associated with the MnS structure. Cyclic voltammetry and differential pulse voltammetry are used to estimate the electrochemical gap at ≈2.47 eV. Absorption optical measurements show tree absorption bands. A broad band between 460 and 520 nm is associated with the first transition in CdTe nanoparticle. The absorption spectrum reveals an optical gap in the range of 2.41–2.33 eV for all the refluxed samples. These values are consistent with those obtained with the electrochemical measurements. The results evidence the formation of a core–shell semiconducting nanostructure made of CdTe nanoparticles coated with a spontaneously self‐assembled thin layer of MnS nanoparticles. [ABSTRACT FROM AUTHOR]

The United States has tightened its technical embargo against China since the Sino-US rivalry began in the mid-2010s, especially in the semiconductor sector. It also has repercussions for China's relations with US allies such as South Korea (or the Republic of Korea, ROK). As China's technical growth is securitized, Sino-ROK collaboration in semiconductor technology becomes politicized, according to a securitization-politicization nexus derived from securitization theory. Under the pressure from Washington, even Korean semiconductor businesses may be forced to 'choose sides'. However, Seoul's pragmatic approach to Beijing prevents the politicization of Sino-ROK technological ties. While demanding security guarantees from Washington, Seoul is unwilling to enhance ties with the US at the price of those with China. Among three scenarios figured out in this paper, South Korea is likely to consolidate its ties with China in semiconductor industry in some form of 'smart' collaboration Ceteris paribus, and this is also in the interest of Beijing. [ABSTRACT FROM AUTHOR]

In this work, the influence of light on the temperature dependence of transverse magnetoresistance oscillations is studied. A generalized mathematical expression that calculates the temperature and light dependence of the quasi-Fermi levels of small-scale p-type semiconductor structures in a quantizing magnetic field is derived. New analytical expressions have been found to represent the temperature dependence of transverse differential magnetoresistance ossillations in dark and light situations, taking into account the effect of light on the ossillations of the Fermi energy of small-scale semiconductor structures. A mathematical model determining the light dependence of the second-order derivative of oscillations of transverse magnetoresistance of p-type semiconductors with quantum wells on magnetic field induction is developed. A new theory explaining the reasons for the significant shift of oscillations of differential magnetoresistance along the vertical axis measured in the experiment for dark and light conditions is proposed. [ABSTRACT FROM AUTHOR]

One of the most striking features of molybdenum oxide is the versatility of its catalytic properties, which are determined by the valence states of molybdenum and its coordination. It may be anticipated that MoO3 surface must contain catalytic sites which are active in different types of elementary steps. MoO3 was successfully synthesized by hydrothermal route at 400 °C, acquiring n-type conduction, due to oxygen deficiency. The single phase, elucidated by X-ray diffraction, crystallizes in an orthorhombic unit cell (Space Group (SG) Pbnm, N° 62) with a crystallite size of 12 nm. MoO3 is a direct band gap semiconductor with a forbidden band value of 2.93 eV where the electrical conduction occurs by low polaron hopping between mixed valences Mo+6/+5 with an activation energy of 0.14 eV. The thermo-power indicates n-type conduction, and confirmed by the capacitance-potential measurement; the latter gives an electrons density of 1.87 × 1020/cm3and a mobility of 1.77 × 10−6 m2/V.s. The flat band potential Vfb (0.11 VSCE) is determined from the capacitance measurement. The physical and chemical characterizations are correlated for the construction of the potential diagram in order to assess the photo electrochemical properties of MoO3 for the oxygen evolution. The valence band, is located above the O2/H2O potential (~ 1.3 VSCE), allowing O2 evolution upon visible light and the oxide is photocathodically protected against corrosion. An evolution rate of 0.13 mL/(mg. h) is obtained within 20 min. at optimal conditions (100 mg of catalyst and 50 °C). Highlights: MoO3 prepared hydrothermally at 400 °C, acquires n-type behavior, due to oxygen vacancies. MoO3 is a direct band gap semiconductor with a forbidden band of 2.93 eV. The conduction occurs between Mo+6/+5 with an activation energy of 0.14 eV. The valence band of the O2/H2O potential (~ 1.3 VSCE), allows O2 evolution upon visible light. [ABSTRACT FROM AUTHOR]

A novel approach for modifying zinc stannate nanomaterials involves using a bio-extract derived from the leaves of Hibiscus rosa-sinensis. Ag nanomaterial and biomolecule sensitization was conducted in a single pot. The composite materials of Ag and biomolecules were characterized using powder X-ray diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy analysis to determine their structural aspects. Based on the PXRD results, it was determined that the composites exhibit a face-centered cubic structure. The observed frequencies of C − H and Sn − O stretching in the FT-IR spectra indicate the existence of biomolecules within the composite material. Furthermore, the X-ray photoelectron spectroscopy findings validate the coordination of zinc and tin within the zinc stannate compound with biomolecules while indicating silver's presence on the surface. Scanning electron microscopy and transmission electron microscopy techniques have revealed the material's porous characteristics and reduction in size of the zinc stannate particles. In addition, the results demonstrated the spherical morphology of the silver particles that have undergone doping. Surface agglomeration and optical characteristics were investigated using UV–Vis spectroscopy. The observed phenomenon exhibits pronounced particle agglomeration resulting from biomolecules on the surface. In addition, the emergence of an additional absorption band at approximately 453 nm can be attributed to silver's surface plasmon resonance effect. The obtained J–V curve for all samples demonstrates the observed enhancements, resulting from incorporating Ag and biomolecules. The enhancements observed in the simulation results were further confirmed through the validation process, which demonstrated the extended absorption and surface plasmon resonance effect. [ABSTRACT FROM AUTHOR]

This study presents a comprehensive approach to vibrational analysis in a size-dependent, orthotropic thermo-piezo-photo-electric semiconductor half-space under Moore–Gibson–Thompson (MGT) photo-thermoelasticity theory with memory-dependent derivatives. Following Eringen's nonlocal elasticity theory, the governing equations for the considered material are derived. The normal mode technique is applied to investigate the photothermal excitation process. Focusing on the interface adjacent to the vacuum, the study considers plasma, thermal, and mechanical stress boundary conditions to determine fundamental physical quantities. Through a detailed exploration, this research examines the impact of various thermo-piezo-photo-electric models, time, nonlocal parameters, and spatial coordinates on different physical quantities. The effects are meticulously analyzed and visually represented through graphical illustrations. While the literature survey reveals numerous studies on vibrational analysis in thermo-piezo-photo-electric semiconductor mediums under different thermoelasticity theories, to the best of the authors' knowledge, no research emphasizing vibrational analysis in a size-dependent thermo-piezo-photo-electric semiconductor medium has been conducted. Moreover, the effect of memory-dependent MGT photo-thermoelasticity theory on a size-dependent thermo-piezo-photo-electric semiconductor half-space has not been illuminated until now, significantly defining the novelty of the conducted research. [ABSTRACT FROM AUTHOR]

Coordination polymers (CPs) are promising for direct X‐ray detection and imaging owing to higher designability and outstanding stability, however, it remains a challenge to achieve highly X‐ray detection performance, particularly both high sensitivity and low detection limit at the same operating voltage. Herein, we construct a new conjugated CP {[Co(BPTTz)(DIPA)] ⋅ DMA}n (1, BPTTz=2,5‐bis(pyridine‐4‐yl)thiazolo[5,4‐d]thiazole, H2DIPA=2,5‐diiodoterephthalic acid, DMA=N, N’‐dimethylacetamide), with multi‐channel charge transfer by regulating the linker mediated electronic‐state, which reduces carrier losses resulting from recombination or quenching, enhances the efficiency of charge separation and transfer, thus further optimizes X‐ray detection performance. The semiconductor prepared based on this strategy achieves record values including the highest mobility‐lifetime product (μτ, 8.05×10−3 cm2 V−1) and the lowest detectable X‐ray dose rate (128 nGyair S−1, 35 V) among CP‐based direct radiation detectors, as well as a high sensitivity (172 μC Gyair−1 cm−2, 35 V) at the same operating voltage. This detector shows excellent long‐time air stability under ambient conditions for over three months and operational stability. These findings demonstrate a rational structural design method to enhance the photoelectronic efficiency and stability of semiconductive CPs. [ABSTRACT FROM AUTHOR]

This manuscript examines the effects of memory-dependent and fractional-order derivatives on a novel generalized piezo-thermo-elastic semiconductor model. The medium is homogenous and orthotropic, subjected to photo-thermal excitation. The governing equations include fractional-order parameters, relaxation time, time delay, and kernel function tailored to specific problem requirements. Normal mode method use to solve the equations, yielding analytical expressions. Graphical representations show physical field distribution across various fractional-order parameters, kernel functions, time delay, and frequency values. This study has the potential to advance precise model development and future simulations. [ABSTRACT FROM AUTHOR]