Applied Physics A最新文献

Cd-doped SnO₂ thin films were deposited by nebulizer spray pyrolysis and systematically investigated for their structural, optical, morphological, and gas sensing characteristics. X-ray diffraction confirmed the tetragonal rutile phase with crystallite sizes in the range of 65–76 nm. Optical transmission studies showed a direct band gap between 4.11 and 4.07 eV, with slight variations due to Cd incorporation. Surface morphology observed by FESEM revealed that doping strongly influenced grain structure: while pure SnO₂ exhibited compact grains, the 3 wt% Cd-doped film displayed a chain-like nanostructure with enhanced porosity and uniform grain distribution. Gas sensing measurements demonstrated that the 3 wt% Cd-doped film exhibited the best response toward NH₃ at room temperature, with a gas response of 1470 % for 250 ppm, a rapid response time of 6.5 s, and a recovery time of 9.1 s. The improved sensing properties were attributed to the synergy between Cd-induced oxygen vacancies, increased surface area, and the chain-like morphology, which provided abundant active sites for adsorption. Furthermore, the sensor’s response was strongly influenced by relative humidity. Higher RH levels facilitated water dissociation into hydroxyl groups, which interacted with adsorbed oxygen species and enhanced NH₃ adsorption, leading to a monotonic increase in response. These results demonstrate that controlled Cd doping optimizes the structure and surface chemistry of SnO₂ thin films, making the 3 wt% composition a promising candidate for room-temperature ammonia detection in humid environments.

Microfluidics-based reactors allow governable synthesis of micro-/nanostructures for an extensive range of applications from materials science, bioengineering to drug delivery. In the current study, hierarchical ZnO nanostructures composed of nanosheets are firstly produced using a viable and rapid method without the use of any template or surfactant via a microfluidic reactor in a continuous motion. This method represents a clear and systematic route to manufacture the 3D ZnO nanostructures compared to the conventionally used synthesis schemes. Perovskite solar cells (PSCs) are fabricated using the produced 3D ZnO nanosheets for the first time ever. The PSCs based on ZnO nanosheets produces the average power conversion efficiency (PCE_avg) of 15.87% and the maximum power conversion efficiency (PCE_max) of 18.97%, thanks to unique nanostructure which increases the chances of improved perovskite penetration into it and rapid electron transport. Conversely, devices based on ZnO nanoparticles lack in performance (PCE_avg = 11.14%) compared to 3D ZnO nanosheets owing to their zero dimensional geometry and slow electron transport.

Vibration suppression has a great interest in acoustic or elastic metamaterial engineering which has a wide range of potential applications and requires the use of lightweight structures and materials to achieve multiple band gaps with multiple generation mechanisms. This paper proposes a rotational triangular lattice composed of the external ligaments of a triangular lattice and a rotational triangle, and explores different band gaps and their generation mechanisms. The effect of the geometric parameters, such as the rotation angle and the slenderness ratio, on the band gap range was considered. By comparing the elastic wave band gaps with the vibration transmission responses, the different band gap generation mechanisms of the rotating triangular lattice were verified. Adjusting the geometric parameters of the rotating triangular lattice, a wide band gap can be achieved, which is used to suppress the propagation of elastic waves. This work provides a new structural design that can achieve multiple band gaps with different generation mechanisms, which is conducive to solving the vibration suppression problem of lightweight passive structures.

Thick, preferentially oriented, and highly conductive LaNiO₃ thin films were successfully grown on silicon wafers through a low-cost chemical solution deposition process. The use of monoethanolamine (MEA) to modify the precursors is crucial for controlling the film thickness, orientation, and electronic properties. When the molar ratio of MEA to LaNiO₃ is 1, the film achieves over 98% c-axis preferred orientation and increased thickness under the same deposition conditions. For ratios greater than zero but less than 0.5, the derived films are randomly oriented, even after rapid thermal annealing. Although all LaNiO₃ films display similar electronic transition characteristics, those deposited with MEA show a lower resistivity of about 0.7 mΩ·cm, compared to 1.41 mΩ·cm for films without MEA at room temperature. The conductivity first increases and then decreases as MEA content rises, due to the combined effects of reduced grain boundaries and altered orientation. BiFeO₃ was also fabricated on the 180 µl-MEA modified-LaNiO₃ electrode, exhibiting a similar (00l) preferred orientation and strong ferroelectric properties. Additionally, optimizing the MEA dosage will aid in developing thick and well-oriented LNO electrodes for silicon-compatible functional devices with the sol-gel.

In this paper, first principles studies using density functional theory were conducted to examine the electronic, half-metallic, and magnetic characteristics of the bulk on MnZrTe (111) and (001) surfaces of the half-Heusler alloy and the MnZrTe/AlSb (111) interfaces. The MnZrTe combination exhibited half-metallic ferromagnetism, showing an energy gap of 1.16 eV at an equilibrium lattice constant of 6.20 Å. The Slater-Pauling rule was used to determine the total magnetic moment, yielding a value of 1µ_B. The findings also demonstrated that the Zr- and Te-terminated (111) surfaces fully preserve the bulk’s half-metallicity, but this characteristic is not observed in Mn-terminated (111), ZrTe-terminated (001), and Mn-terminated (001) surfaces. In addition, the Zr-Sb (111) interface preserved its half-metallic feature, exhibiting complete spin polarization (100%), while the Zr-Al contact of (111) MnZrTe/AlSb forfeited this characteristic. Relative to the total bulk, the atomic magnetic moments of Zr atoms diminish at the Zr-Al and Zr-Sb interfaces, while the magnetic moments of Al atoms at the Zr-Al (111) and Sb atoms at the Zr-Sb (111) interfaces are augmented. The half Heusler MnZrTe alloy is a promising spin filter and spin source for spintronic devices, as our results illustration overall.

In this study, we synthesized AFe₂O₄ (A = Co, Ni, Fe, Mn) ferrites using the hydrothermal technique with urea, glycine and ammonium chloride as the fuel agents. The hydrothermal synthesis took place in an autoclave for 6 h at 190 °C. For characterization, the resulting pellets were calcined for 2 h at 600 °C and sintered for 1 h at 400 °C. X-ray diffraction (XRD) analysis showed that all samples had a face centered cubic (fcc) structure. The samples were investigated for surface morphology using a scanning electron microscope (SEM) which showed that morphology and grain size are affected by A-site substitution. Energy Dispersive X-ray (EDX) spectroscopy verified the elemental configuration and closely agreed with the expected empirical formula. The dielectric characteristics were studied using a precision impedance tester, where we scanned the impedance, tangent loss, AC conductivity, dielectric constant and their variations with frequency. The vibrating sample magnetometer (VSM) was used for measuring the magnetic parameter, we determined that the hysteresis loops were indicative of the formation of ferrimagnetic nanoparticles. We concluded that the A-site substitution had a noticeable influence on the structural, dielectric and magnetic parameters of the AFe₂O₄ ferrites.

Cervical cancer continues to be a major cause of cancer mortality among women globally, primarily because of continued infection with high-risk human papillomavirus (HPV) types In this research, 4-chlorochalcone was act as a potential inhibitor to treat cervical cancer using both spectroscopic and computational methods. Molecular geometry and electronic properties were determined by FT-IR, Raman, and UV–Vis spectroscopy, along with quantum chemical descriptors such as HOMO–LUMO energy gap, chemical hardness, softness, chemical potential, electronegativity, and electrophilicity, and reported to exhibit excellent chemical stability and reactivity. Molecular docking experiments with HPV E6 and E7 oncogenic proteins showed strong binding affinities, which were also validated by non-bonded interaction profiling and molecular dynamics simulations, validating the stability and selectivity of the ligand–protein complexes at longer timescales. Overall, these results reveal 4-chlorochalcone as a lead compound in cervical cancer therapy and provide a computational rationale for further experimental validation and drug development.

We investigate the electronic properties of a two-dimensional quantum ring embedded in a gapped graphene layer containing a topological disclination, under the influence of a uniform magnetic field and an Aharonov-Bohm flux. In this case, the system is modeled within the framework of the Dirac equation for (spin-1/2) particles in a curved background, incorporating both a confinement potential and a non-Abelian gauge field induced by the disclination. Moreover, we have used the exact solutions of the Dirac spinor, from which the corresponding energy spectrum is derived analytically, showing the relation between the topological defect, magnetic fluxes, and the mass gap. To quantify the spatial distribution of the electronic states, we employ Shannon entropy, providing insights into the localization properties of the quasiparticle wavefunctions. In this context, our results illustrate how geometric deformation parameters and external fields collectively influence the energy levels (n) and informational content of quantum states in gapped graphene, offering potential applications in quantum devices and nanoscale electronics.

The coupling of the tribovoltaic effect and photovoltaic effect (Tribo-Photovoltaic Effect) based on semiconductor dynamic heterojunctions represents an emerging mechanical energy harvesting strategy. Although tribovoltaic nanogenerators (TVNGs) have achieved numerous breakthroughs in the development of new materials and device fabrication, in-depth clarification of their physical mechanisms and promotion to practical applications still require extensive exploration. In this study, high-quality 3C-SiC microcrystalline thin films were successfully prepared via chemical vapor deposition (CVD), and a Cu/3C-SiC dynamic Schottky junction was constructed to enable synergistic harvesting of mechanical energy and ultraviolet light. Compared with commercial 4 H-SiC, the 3C-SiC-based TVNG exhibits higher triboelectric current. Typically, under 360 nm illumination with a power intensity of 2 mW/cm², the output current of the 3C-SiC-based TVNG reaches 18.75 µA, representing a 2.35-times enhancement over the dark environment. Furthermore, by deeply investigating the dominant mechanisms of interfacial and built-in electric fields in the tribovoltaic effect, the theoretical possibility of interfacial electric field existence was verified. This work confirms that CVD-processed 3C-SiC thin films possess significant application potential and broad development prospects in the field of high-performance optoelectronic devices.