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Cu3SbSe4-Based materials were fabricated through Sn-doping and AgSb0.98Ge0.02Se2 incorporation and their thermoelectric properties were investigated in the temperature range from 300 K to 675 K. A remarkable enhancement in thermoelectric performance was obtained, which can be ascribed to the synergistic adjustment of electrical and thermal transport. The introduction of AgSb0.98Ge0.02Se2 nanoparticles strengthened phonon scattering in the composites, resulting in a low thermal conductivity. Simultaneously, a high power factor was maintained. As a result, a maximum figure of merit of 1.23 was obtained at 675 K for the sample Cu3Sb0.96Sn0.04Se4–3 wt% AgSb0.98Ge0.02Se2, which is one of the highest values ever reported in the Cu3SbSe4-based system.

Organic-inorganic hybrid materials have drawn increasing attention as photothermal agents in tumor therapy due to the advantages of green synthesis, high loading efficiency of hydrophobic drugs, facile incorporation of theranostic iron, and excellent photothermal efficiency without inert components or additives. Herein, we proposed a strategy for biomimetic engineering-mediated enhancement of photothermal performance in the tumor microenvironment (TME). This strategy is based on the specific characteristics of organic-inorganic hybrid materials and endows these materials with homologous targeting ability and photothermal stability in the TME. The hybrid materials perform the functions of cancer cells to target homolytic tumors (acting as "artificial nanotargeted cells (ANTC)"). Inspired by the pH-dependent disassembly behaviors of tannic acid (TA) and ferric ion (FeIII) and subsequent attenuation of photothermal performance, cancer cell membranes were self-deposited onto the surfaces of protoporphyrin-encapsulated TA and FeIII nanoparticles to achieve ANTC with TME-stable photothermal performance and tumor-specific phototherapy. The resulting ANTC can be used as contrast agents for concurrent photoacoustic imaging, magnetic resonance imaging, and photothermal imaging to guide the treatment. Importantly, the high loading efficiency of protoporphyrin enables the initiation of photodynamic therapy to enhance photothermal therapeutic efficiency, providing antitumor function with minimal side effects.

Cu3SbSe4-based materials have attracted much attention for thermoelectric power generation in the mid-temperature range due to their low cost, ecofriendliness, and abundant elements on the earth. However, the peak figure of merit (ZT) for the Cu3SbSe4-based system prepared by the fusion method is usually smaller than unity because of its high thermal conductivity. Here, we show that through a coprecipitation method combined with spark plasma sintering ultrafine-grained Cu3Sb0.94Sn0.06Se4–ySy (y = 0, 0.5) embedded with Cu3SbSe3 nanoprecipitates can be prepared. Due to the ultralow thermal conductivity and enhanced Seebeck coefficient, a record-high ZT value of 1.32 is achieved for the sample Cu3Sb0.94Sn0.06Se3.5Se0.5. The ultralow thermal conductivity is attributed to the enhanced phonon scattering caused by the nanoprecipitates and fine grains of the samples, and the improved Seebeck coefficient originates from the enhancement of electronic density-of-state effective mass. Present results demonstrate that...

Potassium-ion batteries are promising candidates for large-scale energy storage applications owing to their merits of abundant resources, low cost, and high working voltage. However, the unsatisfying rate performance and cycling stability caused by sluggish K+ diffusion kinetics and dramatic volume expansion hinder the development of potassium-ion batteries. In this study, we design a flexible potassium-ion hybrid capacitor (PIHC) by combining the K-Sn alloying mechanism on the Sn anode and the fast capacitive behavior on the AC cathode with high surface area and mesoporous structure. After optimization, the fabricated Sn||AC PIHC achieves both a high energy density of 120 W h kg-1 and high power density of 2850 W kg-1, much better than other similar hybrid devices. Moreover, a gel polymer electrolyte with a 3D porous structure and high ionic conductivity was employed to improve the structural stability of the Sn anode, which not only realizes good flexibility but also achieves long cycling stability with a capacity retention of nearly 100% for 2000 cycles at a high current density of 3.0 A g-1.

A novel g-C3N4/TiO2/hectorite Z-scheme composites with oxygen vacancy (Vo) defects and Ti3+ were synthesized by so-gel method and high temperature solid phase reaction. This composite exhibited high visible photo-catalytic degradation of rhodamine B (RhB). The apparent rate constant of g-C3N4/TiO2/hectorite was 0.01705 min&minus, 1, which is approximately 5.38 and 4.88 times that of P25 and g-C3N4, respectively. The enhancement of photo-catalytic efficiency of the composites can be attributed to the great light harvesting ability, high specific surface area and effective separation of electrons(e&minus, ) and holes(h+). The F element from Hectorite causes the formation of Vo and Ti3+ in TiO2, making it responsive to visible light. The effective separation of e&minus, and h+ mainly results from Z-scheme transfer of photo-produced electrons in g-C3N4/TiO2 interface. The composites can be easily recycled and the degradation rate of the RhB still reached 84% after five cycles, indicating its good reusability.

Eu-doped ZnO nanosheets were synthesized via a facile and surfactant-free chemical solution deposition method. The detailed characterizations revealed that the as-synthesized samples were well-crystalline which assembled by nanosheets with 25 nm thickness. The Eu ions were successfully doped into the ZnO nanosheets, and the red emissions of Eu3+ ions attributed to the energy of 5D0→7F0, 5D0→7F1 and 5D0→7F2 4f–4f intrashell transitions were observed in PL spectra. The appropriate Eu doping would increase the separation efficiency of electron-hole pairs and promote the formation of the superoxide ions during the photolysis process, which eventually improved the photodegradation of Rhodamine B under UV light irradiation. And the photocatalytic degradation of RhB was also analyzed by a pseudo first order rate. A possible explanation for the modification of bandgap was given based on the modified effect of Eu3+ ions on the electronic structure of ZnO nanosheets, which mainly due to two mechanisms of Burstein-Moss effect and electron-ion/electron scattering.

Exploiting advanced bimetallic oxide as sensing materials for electroanalysis offers new opportunity to improve the electrochemical performance, but still presents a tough challenge. Herein, we synthesized the uniform Fe2O3/Mn3O4 nanocubes from a framework structure in a facile approach, which were developed as the electrochemical catalyst for individual and simultaneous analysis of Cu(II) and Hg(II) in 0.1 M HAc-NaAc buffer solution (pH5.0). It showed the excellent electrochemical behavior for the simultaneous analysis Cu(II) and Hg(II) with high sensitivities of 69.29 and 190.55 μA μM cm−2. The corresponding limit of detection values (LODs) were calculated to be 3.94 nM and 1.39 nM, respectively. The excellent electrochemical behavior of Fe2O3/Mn3O4 could be attributed to the large specific surface area, which could provide a large number of adsorption sites for Cu(II) and Hg(II). Meanwhile, the bimetallic Fe and Mn atoms arranged in the porous nanocubes could offer a synergistic effect and improve the electrochemical activity. Moreover, it could be successfully applied for the simultaneous analysis of Cu(II) and Hg(II) in real water samples with the favorable recovery rate. The results confirmed that the Fe2O3/Mn3O4 nanocubes could serve as a reliable platform for the simultaneous analysis of Cu(II) and Hg(II).

As a global toxic pollutant, lead (Pb(II)) causes serious risks for living organism and the environment, it is thus of critical importance to explore a facile and efficient sensing protocol for the detection of Pb(II). Herein, we proposed the flower-like In-doped Bi2S3 (IDB) with mesoporous nanostructure as an electrochemical sensing interface for the Pb(II) detection, which was synthesized via a facile solvothermal method. The fabricated IDB/GCE exhibited a high sensitivity of 78.1 μA·μM−1 and a satisfied detection limit (LOD) as 0.017 μΜ with robust stability and remarkable anti-interference capability. Plausible mechanism of electrochemical sensing of Pb(II) was proposed based on electrochemical and characterization results, where the mesoporous IDB could provide numerous electrocatalytic active sites, and efficiently accumulate target Pb(II) onto the electrode surface, leading to the improved electrochemical performance. Besides, the complex state of Pb(II) was analyzed with IDB/GCE, and a tentative reference on the detection of complex state of Pb(II) was achieved with the favorable results. Furthermore, the fabricated IDB/GCE could be applied for the analysis of Pb(II) in real water sample with high reliability.

Many methods have been focused on improving the thermoelectric performance of Cu3SbSe4 based materials. However, no effective way can simultaneously achieve the significant improvement of power factor and the remarkable reduction of thermal conductivity. In this work, we introduce AgSb0.98Sn0.02Se2 particles into Cu3Sb0.96Sn0.04Se4 matrix forming Cu3Sb0.96Sn0.04Se4/x wt%AgSb0.98Sn0.02Se2 (x = 0, 1, 3, 5, 7) nanocomposites by milling and spark plasma sintering technique. Due to the reduced thermal conductivity and enhanced carrier mobility, a record-high ZT value of 1.17 is obtained for the sample Cu3Sb0.96Sn0.04Se4/5wt%AgSb0.98Sn0.02Se2. The reduced thermal conductivity is attributed to the enhanced phonon scattering caused by the second phase AgSb0.98Sn0.02Se2 with multiscale size and the enhanced power factor originated from increased carrier mobility due to the reduced carrier concentration, which is caused by the new acceptor energy level related to the interfacial defects. Present results demonstrate that excellent thermoelectric performance can be realized in Cu3Sb0.96Sn0.04Se4 matrix with AgSb0.98Sn0.02Se2 particles embedded.

Potassium-ion batteries (KIBs) are regarded as a potential alternative battery technology to conventional lithium-ion batteries owing to their low potential, natural abundance, and the low cost of potassium. However, sluggish reaction kinetic of the much larger K+ ions leads to low rate capability and poor cycling performance of KIBs, restricting KIB’s practical applications. Herein, we propose a novel full battery called a potassium dual-ion hybrid battery (KDHB) by employing an absorption-type hierarchical porous carbon as the anode material and an anion intercalation-type expanded graphite (EG) as the cathode material. Owing to the hybrid mechanism of the battery and capacitive reaction, the KDHB exhibits superior rate performance with a high capacity of 82 mA h g–1 even at a high current density of 3 A g–1 with negligible capacity decay. Moreover, the KDHB exhibits excellent cycling performance with 74.2% capacity retention after 2000 cycles at 1 A g–1, which is so far the best performance of the repo...

A new three-dimensional cellular system based on the elongated octahedron model [1] is analyzed and discussed mathematically for its compressibility properties. It is shown that there exists negative linear and area compressibility for some certain conformations in this model. In addition, when compared with the octahedral structure, it can be found that this structure has better negative compression effect in the horizontal direction.

The dual-ion battery (DIB) system has attracted great attention owing to its merits of low cost, high energy, and environmental friendliness. However, the DIBs based on sodium-ion electrolytes are seldom reported due to the lack of appropriate anode materials for reversible Na+ insertion/extraction. Herein, a new sodium-ion based DIB named as MoS2 /C-G DIB using penne-like MoS2 /C nanotube as anode and expanded graphite as cathode is constructed and optimized for the first time. The hierarchical MoS2 /C nanotube provides expanded (002) interlayer spacing of 2H-MoS2 , which facilitates fast Na+ insertion/extraction reaction kinetics, thus contributing to improved DIB performance. The MoS2 /C-G DIB delivers a reversible capacity of 65 mA h g-1 at 2 C in the voltage window of 1.0-4.0 V, with good cycling performance for 200 cycles and 85% capacity retention, indicating the feasibility of potential applications for sodium-ion based DIBs.

A simple model for size-dependent melting temperature and melting entropy of nanocrystals embedded in a matrix is introduced to interpret the superheating phenomenon. The model predicts not only melting temperature and the melting entropy increase for embedded nanocrystals as the size of the nanocrystals decreases, but also melting temperature and the melting entropy depression for free-standing nanocrystals with reducing size. The model is supported by available experimental results of nanoparticles and thin films.

Artificial metal nanocluster crystals, (i.e. periodic lattices consisting of identical metal nanoclusters) were fabricated using a novel technique in which surface mediated magic clustering was used to achieve identical cluster size, while the Si(111)-7 × 7 surface was used as a template for ordering the clusters. The universality of this strategy was demonstrated by fabricating more than 10 different nanocluster arrays with different metals and alloys. The atomic structures, formation mechanism and stability of the nanoclusters were studied with in situ scanning tunneling microscopy combined with first-principles total energy calculations. Our study shows that delicate control of growth kinetics is extremely important for cluster crystal fabrication.

Epoxy Molding Compound (EMC) is the encapsulation material that can provide mechanical support and protection to IC packages. In the meantime, it is also a key contributor to package warpage. Finite element analysis (FEA) has been widely used in packaging development to improve product performance more efficiently. EMC is usually modeled as piecewise linear elastic material in FEA model for simplification. However, EMC has viscoelastic properties like other thermosetting materials. During molding and post mold cure (PMC) processes EMC will undergo polymerization conversion and chemical aging that will change its constitutive behavior and hence affect package warpage. In this paper, block warpage of an FBGA (Fine-Pitch Ball Grid Array) package induced by molding and PMC processes was simulated using FEA method by considering viscoelastic effect of EMC. Results showed that chemical shrinkage of EMC can offset effect of thermal shrinkage on block warpage significantly; and PMC process also helped reduce warpage magnitude by a considerable proportion. To verify the simulation results, experiments had been performed to measure the FBGA block warpage after molding and PMC processes. Comparison showed the FEA prediction had good agreement with actual warpage measurement data.

QFN (Quad Flat No-lead) packages become popular in recent years because they provide many advantages over conventional leadframe packages. Due to CTE (Coefficient of Thermal Expansion) mismatch of different materials applied in the package, significant warpage will be generated during QFN packaging process, and may cause yield and reliability issues. In this paper, the warpage of a QFN strip induced by molding process was simulated using finite element analysis (FEA). Effect of stress relief slots design of the leadframe was evaluated, and the influence of material properties was also studied with three different types of EMC (Epoxy Molding Compound). Simulation results indicated that CTE of the EMC had a considerable effect on the warpage direction and magnitude, and the existence of stress relief slots only slightly reduced warpage magnitude.

Warpage is a major reliability concern for IC packages. Package structure, material property and assembly process will all impact warpage behavior, which can be characterized by 3D Finite Element Analysis (FEA). Traditionally, the FEA simulation will only analyze warpage of a free standing package with thermo-mechanical stress induced by Coefficient of Thermal Expansion (CTE) mismatch during cooling process of Epoxy Molding Compound (EMC) from cure temperature to room temperature. In this paper, a dedicated FEA model has been developed to simulate a strip type Fine-Pitch Ball Grid Array (FBGA) package. Different from conventional simulation, effect of both EMC chemical shrinkage due to polymerization conversion during post molding cure and actual measurement operation on warpage have been taken into consideration in the FEA model. Parametric study with different package layout, die area and die thickness has been performed. Result showed package layout of the strip can significantly impact warpage; and die area had more influence on warpage than die thickness. Warpage performance can be improved by optimizing these parameters. Compare to measurement, the simulation result is in good agreement with actual package warpage.

In this paper, performance difference of fine pitch and normal pitch BGA under thermal and mechanical impact conditions has been evaluated by means of thermal shock test as well as board-level drop test. Influence of solder ball material and PCB pad finish was also investigated. The results reveal that decrease of solder ball pitch could lead to increase of vulnerability. Fine pitch BGA fails more rapidly subjected to thermal or mechanical stress. The combination of Sn1.0Ag0.5Cu solder ball and Cu-OSP PCB pad outperformed other testing groups in the research and is recommended for manufacturers. Failure analysis shows that dominant failure mechanism is brittle cracking within or near intermetallics formed between bulk solder and pad metal during soldering reflow process.