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<jats:p>Due to the hydrogen embrittlement effect, La(Fe,Si)<jats:sub>13</jats:sub>-based hydrides can only exist in powder form, which limits their practical application. In this work, ductile and thermally conductive Al metal was homogeneously mixed with La<jats:sub>0.5</jats:sub>Pr<jats:sub>0.5</jats:sub>Fe<jats:sub>11.4</jats:sub>Si<jats:sub>1.6</jats:sub>B<jats:sub>0.2</jats:sub> using the ball milling method. Then hydrogenation and compactness shaping of the magnetocaloric composites were performed in one step via a sintering process under high hydrogen pressure. As the Al content reached 9 wt.%, the La<jats:sub>0.5</jats:sub>Pr<jats:sub>0.5</jats:sub>Fe<jats:sub>11.4</jats:sub>Si<jats:sub>1.6</jats:sub>B<jats:sub>0.2</jats:sub>H<jats:sub> <jats:italic>y</jats:italic> </jats:sub>/Al composite showed the mechanical behavior of a ductile material with a yield strength of ∼ 44 MPa and an ultimate strength of 269 MPa accompanied by a pronounced improvement in thermal conductivity. Due to the ease of formation of Fe–Al–Si phases and the several micron and submicron sizes of the composite particles caused by ball milling process, the magnetic entropy change of the composites was substantially reduced to ∼ 1.2 J/kg⋅K–1.5 J/kg⋅K at 0 T–1.5 T.</jats:p>

<jats:p>Effect of anode area on temperature sensing ability is investigated for a vertical GaN Schottky-barrier-diode sensor. The current-voltage-temperature characteristics are comparable to each other for Schottky barrier diodes with different anode areas, excepting the series resistance. In the sub-threshold region, the contribution of series resistance on the sensitivity can be ignored due to the relatively small current. The sensitivity is dominated by the current density. A large anode area is helpful for enhancing the sensitivity at the same current level. In the fully turn-on region, the contribution of series resistance dominates the sensitivity. Unfortunately, a large series resistance degrades the temperature error and linearity, implying that a larger anode area will help to decrease the series resistance and to improve the sensing ability.</jats:p>

<jats:p>GaAs nanowires (NWs) are ideal materials for preparing near-infrared photodetectors owing to their high charge carrier mobility and direct band gap. Although the performance of GaAs NW photodetectors can be enhanced by surface passivation or doping, it still cannot meet the requirement for applications. In this paper we propose a method to greatly improve the performances of GaAs NW photodetectors by hot-hole injection via surface plasmon polaritons. In this case, the responsivity of a single GaAs NW photodetector is increased by a fact of 3.2 to 6.56 A⋅W<jats:sup>−1</jats:sup> by attaching capsule-like Au nanoparticles to its surface. This research uses an efficient route to improve the NW photocurrent, which is also important for the development of a high-performance near-infrared NW photodetecor.</jats:p>

<jats:p>Reducing the secondary electron yield (SEY) of Ag-plated aluminum alloy is important for high-power microwave components. In this work, Cu doped carbon films are prepared and the secondary electron emission characteristics are studied systematically. The secondary electron coefficient <jats:italic>δ</jats:italic> <jats:sub>max</jats:sub> of carbon films increases with the Cu contents increasing at first, and then decreases to 1.53 at a high doping ratio of 0.645. From the viewpoint of surface structure, the higher the content of Cu is, the rougher the surface is, since more cluster particles appear on the surface due to the small solid solubility of Cu in the amorphous carbon network. However, from viewpoint of the electronic structure, the reduction of the sp<jats:sup>2</jats:sup> hybrid bonds will increase the SEY effect as the content of Cu increases, due to the decreasing probability of collision with free electrons. Thus, the two mechanisms would compete and coexist to affect the SEY characteristics in Cu doped carbon films.</jats:p>

<jats:p>We have realized integration of evanescent wave coupled photodetector (ECPD) and multi-quantum well (MQW) semiconductor optical amplifier (SOA) on MOCVD platform by investigating butt-joint regrowth method of thick InP/InGaAsP waveguides to deep etched SOA mesas. The combination of inductively coupled plasma etching and wet chemical etching technique has been studied to define the final mesa shape before regrowth. By comparing the etching profiles of different non-selective etchants, we have obtained a controllable non-reentrant mesa shape with smooth sidewall by applying one step 2HBr:2H<jats:sub>3</jats:sub>PO<jats:sub>4</jats:sub>:K<jats:sub>2</jats:sub>Cr<jats:sub>2</jats:sub>O<jats:sub>7</jats:sub> wet etching. A high growth temperature of 680 °C is found helpful to enhance planar regrowth. By comparing the growth morphologies and simulating optical transmission along different directions, we determined that waveguides should travel across the regrowth interface along the [110] direction. The relation between growth rate and mask design has been extensively studied and the result can provide an important guidance for future mask design and vertical alignment between the active and passive cores. ECPD-SOA integrated device has been successfully achieved by this method without further regrowth steps and provided a responsivity of 7.8 A/W. The butt-joint interface insertion loss is estimated to be 1.05 dB/interface.</jats:p>

<jats:p>Bi<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub>Se has been proved to be a promising candidate for electronic and optoelectronic devices due to their unique physical properties. However, it is still a great challenge to construct the heterostructures with direct epitaxy of hetero semiconductor materials on Bi<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub>Se nanosheets. Here, a two-step chemical vapor deposition (CVD) route was used to directly grow the CsPbBr<jats:sub>3</jats:sub> nanoplate-Bi<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub>Se nanosheet heterostructures. The CsPbBr<jats:sub>3</jats:sub> nanoplates were selectively grown on the Bi<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub>Se nanosheet along the edges, where the dangling bonds provide the nucleation sites. The epitaxial relationships between CsPbBr<jats:sub>3</jats:sub> and Bi<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub>Se were determined as [200]<jats:sub>Bi<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub>Se</jats:sub>||[110]<jats:sub>CsPbBr<jats:sub>3</jats:sub> </jats:sub> and [110]<jats:sub>Bi<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub>Se</jats:sub>||[200]<jats:sub>CsPbBr<jats:sub>3</jats:sub> </jats:sub> by transmission electron microscopy characterization. The photoluminescence (PL) results reveal that the formation of heterostructures results in the remarkable PL quenching due to the type-I band arrangement at CsPbBr<jats:sub>3</jats:sub>/Bi<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub>Se interface, which was confirmed by ultraviolet photoelectron spectroscopy (UPS) and Kelvin probe measurements, and makes the photogenerated carriers transfer from CsPbBr<jats:sub>3</jats:sub> to Bi<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub>Se. Importantly, the photodetectors based on the heterostructures exhibit a 4-time increase in the responsivity compared to those based on the pristine Bi<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub>Se sheets, and the fast rise and decay time in microsecond. These results indicate that the direct epitaxy of the CsPbBr<jats:sub>3</jats:sub> plates on the Bi<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub>Se sheet may improve the optoelectronic performance of Bi<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub>Se based devices.</jats:p>

<jats:p>Stoichiometric and silicon-rich (Si-rich) SiC films were deposited by microwave electron cyclotron resonance (MW-ECR) plasma enhanced RF magnetron sputtering method. As-deposited films were oxidized at 800 °C, 900 °C, and 1000 °C in air for 60 min. The chemical composition and structure of the films were analyzed by x-ray photoelectron spectroscopy (XPS), Raman spectroscopy and Fourier transform infrared spectroscopy (FT-IR). The surface morphology of the films before and after the high temperature oxidation was measured by atomic force microscopy. The mechanical property of the films was measured by a nano-indenter. The anti-oxidation temperature of the Si-rich SiC film is 100 °C higher than that of the stoichiometric SiC film. The oxidation layer thickness of the Si-rich SiC film is thinner than that of the stoichiometric SiC film in depth direction. The large amount of extra silicon in the Si-rich SiC film plays an important role in the improvement of its high temperature anti-oxidation property.</jats:p>

<jats:p>A regularization of the surface tension anisotropic function used in vapor-liquid-solid nanowire growth was introduced into the quantitative phase-field model to simulate the faceted growth in solidification of alloys. Predicted results show that the value of <jats:italic>δ</jats:italic> can only affect the region near the tip, and the convergence with respect to <jats:italic>δ</jats:italic> can be achieved with the decrease of <jats:italic>δ</jats:italic> near the tip. It can be found that the steady growth velocity is not a monotonic function of the cusp amplitude, and the maximum value is approximately at <jats:italic>ε</jats:italic> = 0.8 when the supersaturation is fixed. Moreover, the growth velocity is an increasing function of supersaturation with the morphological transition from facet to dendrite.</jats:p>

<jats:p>We present a thermodynamically consistent model for diblock copolymer melts coupled with an electric field derived using the Onsager linear response theory. We compare the model with the thermodynamically inconsistent one previously used for the coupled system to highlight their differences in describing transient dynamics.</jats:p>

<jats:p>Excited-state double proton transfer (ESDPT) in the 1-[(2-hydroxy-3-methoxy-benzylidene)-hydrazonomethyl]-naphthalen-2-ol (HYDRAVH<jats:sub>2</jats:sub>) ligand was studied by the density functional theory and time-dependent density functional theory method. The analysis of frontier molecular orbitals, infrared spectra, and non-covalent interactions have cross-validated that the asymmetric structure has an influence on the proton transfer, which makes the proton transfer ability of the two hydrogen protons different. The potential energy surfaces in both S<jats:sub>0</jats:sub> and S<jats:sub>1</jats:sub> states were scanned with varying O–H bond lengths. The results of potential energy surface analysis adequately proved that the HYDRAVH<jats:sub>2</jats:sub> can undergo the ESDPT process in the S<jats:sub>1</jats:sub> state and the double proton transfer process is a stepwise proton transfer mechanism. Our work can pave the way towards the design and synthesis of new molecules.</jats:p>