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Purpose Concerning the radiation effects on the three-dimensional (3D) packaging in space environment, this study aims to investigate the influence of the total dose effect on the transmission characteristics of high-frequency electrical signals using experimental and simulation methods. Design/methodology/approach This work carries out the irradiation test of the specimens and measures their S21 parameters before and after irradiation. A simulation model describing the total dose effect was built based on the experimental test results. And, the radiation hardening design is evaluated by the simulation method. Findings The experimental results demonstrate that the S21 curve of the interconnection decreases with the increase of the irradiation dose, indicating that the total dose effect leads to the decline of its signal transmission characteristics. According to the simulation results, decreasing the height of the through silicon via (TSV), increasing the radius of the TSV, reducing the length of Si and increasing the number of grounded through silicon via have positive effects on improving the radiation resistance of the interconnection structure. Originality/value This work investigates the effect of radiation on the transmission characteristics of interconnection structures for 3D packaging and proposes the hardening design methods. It is meaningful for improving the reliability of 3D packaging in space applications.

The synergistic effect of total ionizing dose (TID) and single event gate rupture (SEGR) in SiC power MOSFETs was investigated via simulation. The device was found to be more sensitive to SEGR with TID increasing, especially at higher temperature. The microscopic mechanism was revealed to be the increased trapped charges induced by TID and subsequent enhancement of electric field intensity inside the oxide layer.

Purpose The purpose of this paper is to investigate the effects of Sn-Ag-x leveling layers on the mechanical properties of SnBi solder joints. Four Sn-Ag-x (Sn-3.0Ag-0.5Cu, Sn-0.3Ag-0.7Cu, Sn-0.3Ag-0.7Cu-0.5 Bi-0.05Ni and Sn-3.0Ag-3.0 Bi-3.0In) leveling layers were coated on Cu pads to prepare SnBi/Sn-Ag-x/Cu solder joints. The microstructure, hardness, shear strength and fracture morphology of solder joints before and after aging were studied. Design/methodology/approach The interfacial brittleness of the SnBi low-temperature solder joint is a key problem affecting its reliability. The purpose of this study is to improve the mechanical properties of the SnBi solder joint. Findings Owing to the addition of the leveling layers, the grain size of the ß-Sn phase in the SnBi/Sn-Ag-x/Cu solder joint is significantly larger than that in the SnBi/Cu eutectic solder joint. Meanwhile, the hardness of the solder bulk in the SnBi/Cu solder joint shows a decrease trend because of the addition of the leveling layers. The SnBi/Cu solder joint shows obvious strength drop and interfacial brittle fracture after aging. Through the addition of the Sn-Ag-x layers, the brittle failure caused by aging is effectively suppressed. In addition, the Sn-Ag-x leveling layers improve the shear strength of the SnBi/Cu solder joint after aging. Among them, the SnBi/SACBN/Cu solder joint shows the highest shear strength. Originality/value This work suppresses the interfacial brittleness of the SnBi/Cu solder joint after isothermal aging by adding Sn-Ag-x leveling layers on the Cu pads. It provides a way to improve the mechanical performances of the SnBi solder joint.

Nanostructured transition metal oxides are promising anode materials for lithium-ion batteries. Nevertheless, the problem of high volume expansion rate limits its further application. In this paper, we present a 3D hierarchical SnO2 hollow nanotubes material by calcining C@SnS2 materials in the air. This structure combines the advantages of both the hollow nanotubes and the outer staggered nanosheets structure, in which the hollow nanotube can provide more lithium ion transport channels, the space between the tubes can buffer the volume change, and the staggering nanosheets structure can effectively improve the relative specific surface area of the material and improve the storage capacity. As a result, the SnO2 hollow nanotubes anode exhibits the highly reversible capacity of 1079 mAh g−1 at a current density of 100 mA g−1, while the reversible specific capacity of 770 mAh g−1 was obtained after 100 cycles. The research results obtained in this work provide a feasible strategy for synthetic nanoscale transition metal oxide as high-performance lithium anode material.

In this study, porous metals (Ni, Cu) with the porosity of 110 and 500 ppi were, respectively, added into the SnBi solder joint to obtain the SnBi@P–Cu and SnBi@P–Ni composite solder joints. To ensure the bonding quality between the solder layers and the Cu substrates, a low pressure of 0.1 MPa was conducted during the soldering process. The microstructure and shear behavior of the composite solder joints were investigated. With the addition of 110 ppi porous metals, the microstructures of the solder joints are mainly composed of porous metals and SnBi solder matrix. As the porosity of P–Cu and P–Ni metals increases to 500 ppi, the concentration of the SnBi matrix decreases sharply in the solder joints. The cross-sectional microstructures of the solder joints present a uniform morphology of P-metals and intermetallic compound (IMC). Here the IMC is Cu6Sn5 in the SnBi@P–Cu joint, but (Ni, Cu)3Sn4 and (Cu, Ni)6Sn5 in the SnBi@P–Ni joint. The shear strength of the SnBi solder joint increases significantly with the addition of porous metals. The average shear strength of SnBi@110P–Cu reaches 85.28 MPa, which is the highest among the investigated solder joints.

Sn-Ag-x solders were used as the interfacial layers between SnBi solder and Cu substrate. The effects of Sn-Ag-x layers on the solderability, microstructure, and mechanical properties of SnBi solde...

Metal foam with excellent ductility was added into nano-Ag sintered joint to obtain the composite sintered joint with a sandwich structure of sintered Ag/metal foam/sintered Ag. The microstructure, shear behavior and fracture morphology of the composite sintered joint were investigated in this study. Experimental results indicate that the addition of ductile metal foam enhances the plasticity of composite sintered joint. As the number of pores of Cu foam increased from 110 to 500 per inch, the shear strength increased from 8.28 to 11.26 MPa. The composite sintered joint with 110ppi (pores per inch) Ni foam showed a higher shear strength than the other composite sintered joints did because of the higher Young’s modules and shear modules of Ni foam. In the Ni foam@nano-Ag composite sintered joint, cracks appeared at the interface between the metal foam and the nano-Ag sintered structure because of the mismatch of coefficient of thermal expansion (CTE). Compared with the Ni foam, the addition of Cu foam effectively depressed the generation of cracks at the interface between the metal foam and the nano-Ag sintered structure.

The effects of porous copper (P-Cu) on the microstructure, hardness, and shear strength of SnBi, SnBi-0.4Ag, and SnBi-1Ag solder joints were investigated in this paper. The experimental results show that P-Cu frames distribute in the solder bulks and form triangular areas. The addition of P-Cu leads to the microstructural refinement in the enclosed areas by the P-Cu frames in the solder bulks. The average hardness here is increased due to the fine grain strengthening mechanism. The SnBi-1Ag@P-Cu solder bulk shows smaller Bi-rich grains but larger β-Sn dendrites than the other two P-Cu-enhanced solder bulks. Porous Cu exists as a frame structure in the solder joints, which hinders the initiation and propagation of cracks and has a positive effect on the improvement of joint strength. Compared to the SnBi and SnBiAg solder joints, the shear strength of the P-Cu-enhanced solder joints is increased by 15%. The average shear strength of the SnBi-0.4Ag@P-Cu solder joint is 79.34 MPa, which is the highest among all the solder joints investigated in this study.

Nanostructured transition metal sulfides are promising anode materials for lithium-ion batteries. Nevertheless, it is still a great challenge to prepare capacity-improved electrodes without reducing their rate capability and cycle stability. In this paper, we present a C/Co

Here, the Ag/amorphous Bi3.15Nd0.85Ti3O12/Pt resistive switching memories were designed and prepared, and the total ionizing dose (TID) effects of 60Co γ-ray on the Ag/amorphous Bi3.15Nd0.85Ti3O12/Pt resistive switching memories were investigated. The results show that the resistance in low resistance state (LRS), resistance in high resistance state (HRS), and set voltage are almost immune to a TID up to 1 Mrad(Si), whereas the reset voltage and forming voltage are impacted slightly. The good radiation immunity is related to the metallic conductive filaments and the amorphous Bi3.15Nd0.85Ti3O12 matrix. These results suggest that the Ag/amorphous Bi3.15Nd0.85Ti3O12/Pt devices show potential for radiation-hard electronics applications.

The fluorescence and effective three-photon absorption (3PA) properties of Zn(II)-[meso-tetrakis(4-octyloxyphenyl)porphyrin] (labeled Zn(II)-porphyrin) dissolved in three different polar solvents were systematically investigated. The electrochemical and photophysical properties of Zn(II)-porphyrin were investigated by 1H NMR spectra, IR spectra, mass spectroscopy, and electronic absorption spectra. The fluorescence emission of Zn(II)-porphyrin in three different solvents excited at the wavelengths of 420 nm (Soret band) and 550 nm (Q-band) were analyzed. By performing Z-scan experiments with femtosecond laser pulses at a wavelength of 800 nm, the effective 3PA process of Zn(II)-porphyrin in three different solvents was observed and the underlying mechanism was discussed in detail. It is found that the fluorescence spectra slightly depend on the polarity of the solvent. Interestingly, the effective 3PA properties of Zn(II)-porphyrin strongly depend on the solvent polarity. The lower the solvent polarity is, the larger effective 3PA cross-section is. Low polar solvents are beneficial to applications of Zn(II)-porphyrin in optical limiting, photodynamic therapy, etc.

To improve the reliability of SnBi solder joints, Ag and porous Cu were used as additives to obtain SnBi-xAg@P-Cu/Cu (x = 0, 0.4, 1 wt%) solder joints. The effect of porous Cu addition on the microstructure, IMC layer, shear behavior and hardness of the solder joints during isothermal aging was studied. The experimental results indicate that there are some areas enclosed by Cu frames in the SnBi-xAg@P-Cu/Cu solder joints. Compared with the SnBi-xAg/Cu solder joints, these areas show a more refined microstructure and higher hardness than the other areas do. After being aged at 100 °C for 600 h, the hardness of the solder bulks showed an increasing trend due to the coarsening of the microstructure. The addition of porous Cu improves the shear strength of the SnBi-xAg/Cu solder joints before and after aging. Among them, SnBi-0.4Ag@P-Cu/Cu shows the highest shear strength. After isothermal aging, the shear fracture transferred from the solder bulk to the soldering interface in the SnBi and SnBi-0.4Ag solder joints. The addition of porous Cu has a positive effect on suppressing the crack propagation in the solder joints. Therefore, the fracture position is mainly located in the solder bulks in the SnBi-xAg@P-Cu/Cu solder joint.

In this paper, the epitaxial hexagonal LuFeO3 (h-LuFeO3) thin films with c-axis-oriented single phase, smooth surface were grown on YSZ (111) substrates by pulsed laser deposition method. Furthermore, a structural distortion of increased lattice constant of c is found in the epitaxial h-LuFeO3 thin films. Moreover, the epitaxial h-LuFeO3 thin films show room-temperature ferromagnetism. The coercive field and remnant magnetization of the epitaxial h-LuFeO3 thin film decrease with the increase in the test temperature from 50 to 300 K. The study would be of benefit to the room-temperature single-phase multiferroic materials.

Perovskite solar cells have excellent photoelectric properties, but their physical mechanism of anti-irradiation is still incomplete. In this work, we investigate the photoelectrical properties of mixed cation perovskite solar cells by performing electron irradiation experiments, characterization measurements (i.e. photoluminescence spectra, UV–vis absorption spectra, and quantum efficiency spectra), and Monte Carlo simulation analysis. It is found that the electrical performance of solar cells degrades more severely with increasing electron irradiation fluence. Specifically, the open-circuit voltage independent of the electron irradiation is attributed to the stability of perovskite materials. The short-circuit current density (alternatively, photoelectric conversion efficiency) of irradiated solar cells decreases because two main reasons: the blackening of the glass substrate hampers the short-wavelength light to reach the photosensitive layer, and the Au electrode has a large number of recombination centers to shorten the carrier lifetime. It is suggested that the mixed cation perovskite solar cell has anti-electron irradiation performance by adopting the anti-irradiation glass and electrode.

In order to improve the mechanical behavior of the low-temperature [Formula: see text] (SnBi) lead-free solder joint, the [Formula: see text] (SACBN) solder ball with the diameter of 400 [Formula: see text]m was pre-soldered on Cu to obtain the SnBi/SACBN/Cu composite joint. The microstructure and shear behavior of the solder joints were investigated. Experimental results indicate that SnBi solder is well bonded on the SACBN bump due to the elemental diffusion and dissolution between the molten SnBi and solid SACBN bump during the soldering process. The addition of the SACBN bump shows a significant effect on the formation and growth of the [Formula: see text]-Sn grains in the SnBi bulk. Compared with the SnBi/Cu joint, the SnBi bulk in the composite joint shows enlarged [Formula: see text]-Sn dendritic grains. Meanwhile, the interfacial intermetallic compound (IMC) layer transforms from Cu6Sn5 into (Cu, Ni)6Sn5. Among these three solder joints, the shear strength of the SACBN/Cu joint is the highest, reaching 86.7 MPa. The shear strength of the SnBi/Cu solder joint is enhanced by the SACBN bump from 68.2 MPa to 75.2 MPa. Additionally, the addition of the SACBN bump shows a positive effect on suppressing the brittleness of the SnBi/Cu solder joint.

Nanostructured transition metal sulfides are promising anode materials for lithium-ion batteries. Nevertheless, it is still a great challenge to prepare capacity-improved electrodes without reducing their rate capability and cycle stability. In this paper, we present a C/Co9S8@SnS2 composite material by loading SnS2 nanocrystals onto MOF-derived C/Co9S8 nanostructures. The C/Co9S8@SnS2 composite has multiple active sites to store lithium ions. The specific capacity reaches 3.1 mAh cm−2 when the current density is 0.224 mA cm−2. The asynchronous electrochemical reaction between Co9S8 and SnS2 offsets the volume expansion of the anode material. Meanwhile, the compact adhesion of carbon layers on the interfaces suppresses the destruction of the anode during the charging–discharging processes. Consequently, the synthesized electrode presents favorable capacity with high current density or under long-term cycling conditions. The prepared battery has a reversible specific capacity of 0.452 mAh cm−2 and a coulomb efficiency of 99.7% after 500 cycles with a high current density of 2.24 mA cm−2. The research results obtained in this work provides a feasible strategy to improve the performance of electrodes systematically.

Generation of vectorial optical fields with arbitrary polarization distribution is of great interest in plenty of applications. In this work, we propose and experimentally demonstrate the generation of a second-order full Poincare (FP) beam and its application in two-dimensional (2D) flattop beam shaping with spatially variant polarization under a high numerical aperture focusing condition. In addition, the force mechanism of the focal field with 2D flattop beam profile is numerically studied, demonstrating the feasibility to trap a dielectric Rayleigh particle in three-dimensional space. The results show that the additional degree of freedom provided by the FP beam allows one to control the spatial structure of polarization, to engineer the focusing field, and to tailor the optical force exerted on a dielectric Rayleigh particle. The findings reported in the work may find useful applications in laser micromachining, optical trapping, and optical assembly.

The nonlinear ellipse rotation usually occurs when an elliptically polarized beam propagates through an isotropic nonlinear medium owing to the existence of χ1221(3). Here we report the radial-variant nonlinear ellipse rotation of a vector beam with structured elliptical polarization through isotropic Kerr nonlinearities. Due to the interaction of elliptically polarized vector beams (EPVBs) with isotropic nonlinear media, the distributions of both the orientation angle and the ellipticity angle of beams at the far-field observational plane exhibit multiple concentric ring structures with the circularly symmetry. Numerical simulations show that the self-diffraction intensity pattern, the distribution of the state of polarization, and the spin angular momentum (SAM) distribution of an EPVB could be manipulated by tuning both the isotropic optical nonlinearity and the chirality parameter of the vector beam, which may find direct applications in polarization-control optical switching, SAM manipulation, and optical polarization encoding or detection.

By performing the femtosecond-pulsed [Formula: see text]-scan experiments at a wavelength of 780[Formula: see text]nm, we report the observation of simultaneous third- and fifth-order refractive nonlinearities in the film of a side-chain azobenzene copolymer synthesized by free-radical polymerization method. Theoretically, we extend two continuous wave [Formula: see text]-scan theories suitable for the excitation of ultrafast laser pulses. First one is valid only for the situation of the sample with the pure third-order refractive nonlinearity. Second one is applicable when the sample exhibits the simultaneous third- and fifth-order refractive nonlinearities. Both [Formula: see text]-scan theories allow the precise analysis of femtosecond-pulsed [Formula: see text]-scan experimental data. Using the femtosecond time-resolved optical Kerr effect measurements, we estimate the nonlinear response time of the sample to be in the sub-picosecond regime. The physical mechanisms of the observed nonlinearity are also discussed. The high nonlinear figure of merit with ultrafast response in this polymer is desirable in nonlinear photonic devices.

We generate a new kind of azimuthal-variant vector field with a distribution of states of polarization (SoPs) described by the square of the azimuthal angle. Owing to asymmetrical SoPs distribution of this localized linearly polarized vector field, the tightly focused field exhibits a double half-moon shaped pattern with the localized elliptical polarization in the cross section of field at the focal plane. Moreover, we study the three-dimensional distributions of spin and orbital linear and angular momenta in the focal region. We numerically investigate the gradient force, radiation force, spin torque, and orbital torque on a dielectric Rayleigh particle produced by the tightly focused vector field. It is found that asymmetrical spinning and orbiting motions of trapped Rayleigh particles can be realized by the use of a tight vector field with power-exponent azimuthal-variant SoPs.

We report the large enhancement of optical limiting effects by exploiting the anisotropy of a two-photon absorber and manipulating the polarization distribution of the light field simultaneously. After modeling the polarization-orientation dependence on the two-photon absorption (TPA) coefficient, we demonstrate the enhanced TPA effect on an anisotropic two-photon absorber using radially polarized beams (RPBs) and show its interesting applications through the Z-scan technique and an optical limiter. The numerical results reveal that both the sensitivity of the Z-scan technique and the optical limiting effect on an anisotropic two-photon absorber using RPBs have great enhancement compared with those on an isotropic two-photon absorber and using linearly polarized Gaussian beams. The presented work opens up new avenues for the enhancement of polarization-dependent nonlinear optical effects, which have potential applications in two-photon lithography, polarization-sensitive photodetectors, and multi-photon photoluminescence imaging.

Structured intense laser interacting with matter will result in a variety of novel nonlinear optical effects, modulate the light propagation behavior, and change the structural property of a material. In this work, we theoretically investigate the spatial self-phase modulation (SSPM) effect, nonlinear ellipse rotation, and spin angular momentum (SAM) flux redistribution of hybridly polarized vector beams through isotropic Kerr nonlinearities. Experimentally, we observe the SSPM effect of the femtosecond-pulsed hybridly polarized vector beam in carbon disulfide at 800 nm, which is in agreement with the theoretical predictions. Our results show that the SSPM intensity pattern, the distribution of state of polarization (SoP), and the SAM flux of a hybridly polarized vector beam could be manipulated by tuning the isotropic optical nonlinearity, which may find interesting applications in nonlinear mechanism analysis, nonlinear optical characterization, and SAM manipulation.

Light fields with structured polarization distribution interacting with structured media will result in many novel optical effects in both the linear and nonlinear regimes. In this work, we report a theoretical investigation of both vectorial self-diffraction behaviors and polarization evolution characteristics of a radially polarized beam induced by anisotropic Kerr nonlinearity. By taking the polarization-orientation dependence of the third-order refractive nonlinearity, we study the far-field vectorial self-diffraction patterns of the radially polarized beam using the vectorial Rayleigh-Sommerfeld formulas. Numerical results reveal that the self-diffraction patterns with a four-fold rotational symmetry exhibit hybrid states of polarization. Moreover, the interaction of radially polarized beams with the anisotropic nonlinear Kerr media leads to the redistribution of the spin angular momentum (SAM) flux in the far-field plane. The presented work opens up new avenues for varying polarization and SAM through anisotropic optical nonlinearity.

In this paper, based on an analysis of the mechanisms of electron irradiation of the S781 thermal control white paint (pigment ZnO) and the theories of irradiation dose depth distribution and photon absorption in materials, a model is built using the method of delamination analysis that explains the relationship between the variation of the material’s spectrum absorption and electron irradiation energy.The uncertain parameters in the model, with the use of the experimental data, can be calculated by Matlab using the curve fitting by the least squares procedure. The accuracy of the model and the feasibility of the calculating methods have been verified by experiments. The model can be applied to predict the degradation of ZnO white paint’s optical characteristics under space radiation environments.