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<jats:p>Based on ab initio calculations, it is found that the donor center of substitutional sulfur (S) in diamond with <jats:inline-formula> <jats:tex-math> <?CDATA ${C}_{2v}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>C</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>2</mml:mn> <mml:mi>v</mml:mi> </mml:mrow> </mml:msub> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_8_088102_ieqn1.gif" xlink:type="simple" /> </jats:inline-formula> symmetry is more stable than that with <jats:inline-formula> <jats:tex-math> <?CDATA ${C}_{3v}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>C</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>3</mml:mn> <mml:mi>v</mml:mi> </mml:mrow> </mml:msub> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_8_088102_ieqn2.gif" xlink:type="simple" /> </jats:inline-formula> symmetry, which is different from previous reports in literature. The energy difference of <jats:inline-formula> <jats:tex-math> <?CDATA ${C}_{2v}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>C</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>2</mml:mn> <mml:mi>v</mml:mi> </mml:mrow> </mml:msub> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_8_088102_ieqn3.gif" xlink:type="simple" /> </jats:inline-formula> and <jats:inline-formula> <jats:tex-math> <?CDATA ${C}_{3v}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>C</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>3</mml:mn> <mml:mi>v</mml:mi> </mml:mrow> </mml:msub> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_8_088102_ieqn4.gif" xlink:type="simple" /> </jats:inline-formula> structures is qualitatively affected by the supercell size, and the 216-atom supercell could be proposed as the minimum to obtain stable configuration of substitutional S in diamond. Using supercells of up to 512 atoms, the donor level of substitutional S with <jats:inline-formula> <jats:tex-math> <?CDATA ${C}_{2v}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>C</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>2</mml:mn> <mml:mi>v</mml:mi> </mml:mrow> </mml:msub> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_8_088102_ieqn5.gif" xlink:type="simple" /> </jats:inline-formula> symmetry is deep.</jats:p>

<jats:p>Single-crystal GaN layers have been obtained by nitriding <jats:italic>β</jats:italic>-Ga<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> films in NH<jats:sub>3</jats:sub> atmosphere. The effect of the temperature and time on the nitridation and conversion of Ga<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> films have been investigated. The nitridation process results in lots of holes in the surface of films. The higher nitridation temperature and longer time can promote the nitridation and improve the crystal quality of GaN films. The converted GaN porous films show the single-crystal structures and low-stress, which can be used as templates for the epitaxial growth of high-quality GaN.</jats:p>

<jats:p>Natural aluminum particles have the core–shell structure. The structure response refers to the mechanical behavior of the aluminum particle structure caused by external influences. The dynamic behavior of the structural response of aluminum core–shell particles before combustion is of great importance for the aluminum powder burning mechanism and its applications. In this paper, an aluminum particle combustion experiment in a detonation environment is conducted and analyzed; the breakage factors of aluminum particles shell in detonation environment are analyzed. The experiment results show that the aluminum particle burns in a gaseous state and condenses into a sub-micron particle cluster. The calculation and simulation demonstrate that the rupture of aluminum particle shell in the detonation environment is mainly caused by the impact of the detonation wave. The detonation wave impacts the aluminum particles, resulting in shell cracking, and due to the shrinkage-expansion of the aluminum core and stripping of the detonation product, the cracked shell is fractured and peeled with the aluminum reacting with the detonation product.</jats:p>

<jats:p>Gate-grounded N-channel MOSFET (GGNMOS) has been extensively used for on-chip electrostatic discharge (ESD) protection. However, the ESD performance of the conventional GGNMOS is significantly degraded by the current crowding effect. In this paper, an enhanced GGNMOS with P-base layer (PB-NMOS) are proposed to improve the ESD robustness in BCD process without the increase in layout area or additional layer. TCAD simulations are carried out to explain the underlying mechanisms of that utilizing the P-base layer can effectively restrain the current crowing effect in proposed devices. All devices are fabricated in a 0.5-<jats:inline-formula> <jats:tex-math> <?CDATA ${\rm{\mu }}{\rm{m}}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi mathvariant="normal">μ</mml:mi> <mml:mi mathvariant="normal">m</mml:mi> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_28_8_088501_ieqn3.gif" xlink:type="simple" /> </jats:inline-formula> BCD process and measured using the transmission line pulsing (TLP) tester. Compared with the conventional GGNMOS, the proposed PB-NMOS devices offer a higher failure current than its conventional counterpart, which can be increased by 15.38%. Furthermore, the PB-NMOS_type3 possesses a considerably lower trigger voltage than the conventional GGNMOS to protect core circuit effectively.</jats:p>

<jats:p>The instability of p-channel low-temperature polycrystalline silicon thin film transistors (poly-Si TFTs) is investigated under negative gate bias stress (NBS) in this work. Firstly, a series of negative bias stress experiments is performed, the significant degradation behaviors in current–voltage characteristics are observed. As the stress voltage decreases from −25 V to −37 V, the threshold voltage and the sub-threshold swing each show a continuous shift, which is induced by gate oxide trapped charges or interface state. Furthermore, low frequency noise (LFN) values in poly-Si TFTs are measured before and after negative bias stress. The flat-band voltage spectral density is extracted, and the trap concentration located near the Si/SiO<jats:sub>2</jats:sub> interface is also calculated. Finally, the degradation mechanism is discussed based on the current–voltage and LFN results in poly-Si TFTs under NBS, finding out that Si–OH bonds may be broken and form Si* and negative charge OH<jats:sup>−</jats:sup> under negative bias stress, which is demonstrated by the proposed negative charge generation model.</jats:p>

<jats:p>Heterojunctions composed of <jats:italic>β</jats:italic>-Ga<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> and ZnO films are fabricated on sapphire substrates by using the laser molecular beam epitaxy method. The heterojunction possesses excellent rectifying characteristics with an asymmetry ratio over 10<jats:sup>5</jats:sup>. Prominent solar-blind photoresponse effect is also observed in the formed heterojunction. The photodetector exhibits a self-powered behavior with a fast response speed (rise time and decay time are 0.035 s and 0.032 s respectively) at zero bias. The obtained high performance can be related to the built-in field driven photogenerated electron-hole separation.</jats:p>

<jats:p>Electrical spin, which is the key element of spintronics, has been regarded as a powerful substitute for the electrical charge in the next generation of information technology, in which spin plays the role of the carrier of information and/or energy in a similar way to the electrical charge in electronics. Spin-transport phenomena in different materials are central topics of spintronics. Unlike electrical charge, spin transport does not depend on electron motion, particularly spin can be transported in insulators without accompanying Joule heating. Therefore, insulators are considered to be ideal materials for spin conductors, in which magnetic insulators are the most compelling systems. Recently, we experimentally studied and theoretically discussed spin transport in various antiferromagnetic systems and identified spin susceptibility and the Néel vector as the most important factors for spin transport in antiferromagnetic systems. Herein, we summarize our experimental results, physical nature, and puzzles unknown. Further challenges and potential applications are also discussed.</jats:p>

<jats:p>Spinel ferrites have a significant role in high-tech applications. In the present work nano-crystalline ferrites having general formula Co<jats:sub>0.5</jats:sub>Cd<jats:sub>0.5</jats:sub>Bi<jats:sub> <jats:italic>x</jats:italic> </jats:sub>Fe<jats:sub>2−<jats:italic>x</jats:italic> </jats:sub>O<jats:sub>4</jats:sub> with (<jats:italic>x</jats:italic> = 0.0, 0.05, 0.1, 0.15, 0.2, and 0.25) are synthesized via micro-emulsion route. Powder x-ray diffraction (XRD) studies discover the FCC spinel structure. Crystalline size is calculated in a range of 11 nm–15 nm. Lattice parameter calculations are reduced due to its substitution which leads to the exchange of large ionic radius of Fe<jats:sup>3+</jats:sup> for small ionic radius of Bi<jats:sup>3+</jats:sup>. The x-ray density is analyzed to increase with doping. Fourier transform infrared spectroscopy (FTIR) is performed to analyze absorption band spectra. The two absorption bands are observed in a range of 400 cm<jats:sup>−1</jats:sup>–600 cm<jats:sup>−1</jats:sup>, and they are the characteristic feature of spinel structure. Thermo-gravimetric analysis (TGA) reveals the total weight loss of nearly 1.98%. Dielectric analysis is carried out by impedance analyzer in a frequency span from 1 MHz to 3 GHz by using the Maxwell Wagner model. Dielectric studies reveal the decrease of dielectric parameters. The alternating current (AC) conductivity exhibits a plane behavior in a low frequency range and it increases with the applied frequency increasing. This is attributed to the grain effects in a high frequency range or may be due to the reduction of porosity. Real and imaginary part of impedance show the decreasing trend which corresponds to the grain boundary action. The imaginary modulus shows the occurrence of peak that helps to understand the interfacial polarization. Cole-Cole graph shows a single semicircle which confirms that the conduction mechanism is due to the grain boundaries at low frequency. Dielectric studies reveal the applicability of these ferrites in high frequency equipment, microwave applications, high storage media, and semiconductor devices.</jats:p>

<jats:p>A new transparent photovoltaic panel composed of a luminescent solar concentrator and Al/BaTiO<jats:sub>3</jats:sub>/ZnO/Pt ferroelectric solar cells is presented, in which a portion of the incoming solar illumination is converted by the fluorophores to ultraviolet (UV) light which is then absorbed by ZnO. Firstly, the solar cells are simulated using Atlas–Silvaco. Then, the panel is modelled based on the obtained solar cell characteristics. This panel would be of great importance for building integrated photovoltaics domain because of its high transparency.</jats:p>

<jats:p>Bulk heterojunction, non-fullerene PBDB-T:ITIC blend polymer solar cells have been fabricated. The active layers consisting of PBDB-T as a donor and ITIC as an acceptor are optimized using a series of alkylthiol additives (1,3-propanedithiol, 1,4-butanedithiol, and 1,8-octanedithiol). It is found that the donor and acceptor are phase separated with different crystalline domains. The additives effectively re-organize the morphology and extend the molecule ordering in lamellar structure with increased correlation length in ITIC domain, benefiting the generation and dissociation of exciton and reducing charge recombination. A substantial improvement in power conversion efficiency of the devices from 8.13% to 9.44% is observed. This study shows that the application of alkylthiol additives is a simple and effective approach to improve the device performance in solar cells based on polymer/non-fullerene blend system.</jats:p>