Applied Research最新文献

Optoelectronic devices performance is governed by the band alignment nature in heterojunctions. Interfacial Layers (ILs) play an immense role in charge carrier-selectivity and their transport behavior. Considering the investigations on a wide array of solid-state surfaces and heterojunctions performed both experimentally and theoretically, we found that the electron localizability, which is quantifiable through the bandgap energy and band width, affects the surface properties of crystals and hence the electronic properties of the interfaces. In combination with other observations, a strategy for contact design is developed for enhancing charge carrier transport across the boundaries and the interfaces, one can optimize stack structures with IL by maximizing their respective transport mechanism, similar to what has been done with silicon solar cells by doping. In this case, charge carrier transport across the interface can be maximized by making the depletion region width smaller without altering the heterojunction barrier's height.

In recent years, some homomorphic encryption algorithms have been proposed to provide additive homomorphic encryption and multiplicative homomorphic encryption. However, similarity measures are required for searches and queries under homomorphic encrypted ciphertexts. Therefore, this study considers cosine similarity, angular similarity, Tanimoto similarity, and soft cosine similarity and combines homomorphic encryption algorithms for similarity calculation to propose homomorphic encryption-based cosine similarity (HE-CS), homomorphic encryption-based angular similarity (HE-AS), homomorphic encryption-based Tanimoto similarity (HE-TS), and homomorphic encryption-based soft cosine similarity (HE-SCS). This study proposes mathematical models to prove the proposed homomorphic encryption-based similarity calculation methods and gives practical cases to explain the feasibility of the proposed HE-CS, HE-AS, HE-TS, and HE-SCS. Furthermore, this study proposes normalized entropy and normalized Gini impurity as evaluation factors to measure the randomness and confusion of ciphertext. In experiments, the values of normalized entropy and normalized Gini impurity are higher than 0.999, which indicates significant differences between plaintexts and ciphertexts. Moreover, the encryption time and decryption time of the proposed homomorphic encryption-based similarity calculation methods have been evaluated under different security strengths.

Fully screen-printed silver and copper temperature sensors were studied up to 100°C. The influence of the processing conditions and the composition of three silver and one copper commercial inks is analyzed in this study. The curing temperature is extremely relevant to stabilize the initial resistance of silver sensors, especially for those printed with the lowest solid content ink. All printed sensors showed good linear behavior in the range of 25–100°C (R² > 0.999) except for those fabricated with the lowest solid content silver ink, which also displayed the highest hysteresis and drift. The temperature coefficient of resistance (TCR) obtained for the copper sensors was 3.367 × 10⁻³ K⁻¹ and for the three silver sensors, it ranged between 2.723 × 10⁻³ to 2.963 × 10⁻³ K⁻¹. This TCR is higher than values reported for inkjet-printed resistive temperature detectors. Overall, this work demonstrates that low-cost, linear, screen-printed temperature sensors can be successfully fabricated on flexible substrates.

Solar-driven overall water splitting using particulate photocatalysts represents a sustainable route to generate H₂. In this minireview, we outline recent progress in hybridization strategies in constructing high- performance cocatalyst/photocatalyst systems. We discussed the fundamental principles of photocatalytic water splitting and the pivotal role of cocatalysts. We placed special emphasis on understanding the structure-activity relationship of cocatalysts for effective photocatalytic H₂ production from pure H₂O. We expect this review to offer insights and stimulate further research interest in the development of high-performance cocatalysts for photocatalytic water splitting.

In recent years, the interest in structured hydrophobic surfaces has considerably grown, finding applications in many industrial fields, including aerospace, automotive, and biomedical. Three-dimensional (3D) printing technology is a simple, rapid, and economic process to fabricate structured surfaces based on neat polymers and composite materials, allowing working with a wide variety of plastic materials. The manufactured surfaces show a roughness depending on the printing design and the printing resolution: this characteristic is ideal to achieve superhydrophobic properties. Furthermore, patterned surface structures can be printed by fused filament fabrication (FFF), so increasing the hydrophobic character of the samples; indeed, micro- and nanosurface structures are required to make a hydrophobic surface. In this study, 3D micropatterned textures of pillars were printed by FFF using polylactide (PLA) and polypropylene (PP) as polymer filaments and PLA/carbon nanotubes (PLA/CNTs) and PP/carbon fibers (PP/CF) as composite filaments. Morphologies of printed specimens were analyzed by optical microscopy and scanning electron microscopy. Good correspondence was found between pillar dimensions and edge-edge pillars distance of computer aided design (CAD) and composites 3D-printed samples. Their wettability was evaluated by static contact angle (CA) measurements. Results clearly show a significant increase of water CA values up to 50% in all micropatterned samples with respect to flat surfaces. This improvement was achieved by surface microstructuring without the use of nanoparticles and/or chemical treatment.

Magnetic nanoparticles have recently attracted attention for biochemical and medical applications like drug delivery and hyperthermia for a variety of reasons with most important being their stability, chemical compatibility, and suitable magnetic properties like moderate specific mass magnetization. Cobalt ferrites are a well-studied family of materials and the partial substitution of Fe³⁺ cations by rare earth (RE) ones may be used to tune the magnetic properties. In the present work pure and substituted Co ferrite nanoparticles with nominal stoichiometry CoFe_2−xR_xO₄ (R = Yb, Gd; x = 0.05, 0.1, 0.3) synthesized by the co-precipitation method are studied with ⁵⁷Fe Mössbauer spectroscopy to determine the incorporation of RE ions in the spinel lattice. The fitting procedure was based on the standard spinel model using two sextets for the octahedral and the tetrahedral coordinated positions of Fe atoms. All isomer shift values were found within the typical range of high spin ferric ions while quadrupole splitting values strongly suggest that there is a substitution preference; RE ions replace iron ones in octahedral sites. The inversion parameter was found to decrease with RE content (lowest value about 0.534 for CoFe_1.90Yb_0.10O₄) and thermal treatment always results in changing the material toward normal spinel, while pure CoFe₂O₄ was inverse. Thermal treatment of substituted materials in ambient air at temperature range 1500–1700 K for 12 h increase crystallite size and changes the degree of inversion.

This treatise showcases the design as well as modeling about a photodetector (PD) based on AgInSe₂ (AISe), a direct bandgap chalcopyrite with a bandgap of 1.19 eV. The PD exhibits outstanding optical and electronic characteristics, showcasing remarkable performance. The PD has been systematically investigated by varying the width, carrier density, and defect densities of specific layers, as well as the interface defect density of specific interfaces. Various layers are optimized to enhance the overall performance of the PD and the impact of different device resistances is analyzed. The photocurrent (J_SC) and voltage (V_OC) of the heterostructure photodetector are determined to be 38.60 mA/cm² and 1.0 V, in turn. The maximum responsivity (R) and detectivity (D*) are identified as 0.70 A/W and 4.60 × 10¹⁶ Jones, respectively at a wavelength of 940 nm. The spectral response exhibits significantly higher values in the range of 800–1000 nm, indicating the device's capability to detect near-infrared (NIR) light. This research provides valuable insights for the manufacturing of AISe material-based photodetectors with enhanced performance.

The aqueous extract of endophytic fungi (Periconia sp.) was effectively used as a reducing agent to anchor Ag nanoparticles on the ZnO surface. The XRD, UV-Vis, SEM-EDX and TEM analyses were performed to ensure the formation of AgNP@ZnO architecture. TEM analysis confirmed that the 4–20 nm sized Ag nanoparticles were anchored evenly on the surface of ZnO with 16–78 nm in size. The antimicrobial study showed the superior performance of AgNP@ZnO functional nanoparticles than the pristine ZnO against pathogenic bacteria Staphylococcus aureus (gram-positive) and Escherichia coli (gram-negative). Hence, AgNP@ZnO functional particles were effectively explored as antimicrobial reinforcement for fabricating composite films using polylactic acid (PLA) as a matrix. The obtained nanocomposite films showed excellent antibacterial activity, which increases with increasing AgNP@ZnO loading.

Multiphase polymeric materials and applications play a prominent role in our society. One of the key challenges is the design and modification of their macromolecules so that the composition and structuring of the phases as well as the interactions between them can be controlled from the molecular scale onwards. In the present contribution, it is highlighted that more recently developed event driven (kinetic) Monte Carlo models provide an interesting framework to grasp molecular variations over various length scales. The strength lies in the tracking of individual molecules per phase of interest so that interphase transfer events can be sampled based on the distributed nature of the (macro)molecules present. Hence, the micro-scale of local concentrations and temperatures can be connected to the meso-scale defining interphase transport and morphological variations, with an additional connection to the macro- or application scale within reach by adding macro-scale transfer events to the overall sampling scheme. Starting from a benchmark coupled matrix based Monte Carlo (CMMC) study on the multiphase formation of engineering composites which explicitly acknowledges the type of (macro)molecules present in each phase, it is showcased that the CMMC framework can support the general field of energy and electronics applications. This is highlighted through (i) a case study devoted to the design of polymer electrolytes for batteries, and (ii) a case study on blend design for the regulated stretching of piezoresistive sensors.

Heptamethine based cyanines, namely 1,3,-trimethyl-2-(2-2[2-phenylsulfanyl-3-[2-(1,3,3-trimethyl-1,3,3-trithyl-1,3-dihydro-indol-2-ylidene)-ethylidene]cyclohex-1-enyl]vinyl)-3H-indolium chloride (S1) and 2-[2-(2-chloro-[2-[1,1-dimethyl-7-sulfo-3-(4-sulfobutyl)-1,3-dihydro-benzo[e]indol-2-ylidene]-ethylidene]cyclopent-1-enyl]vinyl]-1,1-dimethyl-7-sulfo-3-(4-sulfobutyl)-1Hbenzo[e]indolium hydroxide, inner salt, triethylammonium salt (S2), efficiently result in physical drying of an aqueous dispersion comprising a polyurethane binder. S2 possesses a water solubility of 40 g/L. A high-intensity near-infrared-LED emitting at 820 nm with an intensity of 1 W/cm² served as light source. The cyanine converted the light absorbed into heat by internal conversion needing less drying time compared to conventional drying. Water content after film formation showed less then 1%. In the second step, ultraviolet (UV) exposure with a LED emitting at 395 nm resulted in formation of semi-interpenetrating polymer networks by crosslinking of the multifunctional (meth)acrylate operating as reactive diluent. Ethyl phenyl(2,4,6-trimethylbenzoyl)phosphinate-L served as effective UV-photoinitiator. Furthermore, the UV-exposure together with Norrish Type I and Type II photoinitator systems results in a very efficient bleaching of the green physical dried film. This contribution shows for the first time a new photonic hybrid technique describing successful replacement of an oven-based process by a photonic based step that generates heat needed for drying.