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<jats:p>The interface state of hydrogen-terminated (C–H) diamond metal–oxide–semiconductor field-effect transistor (MOSFET) is critical for device performance. In this paper, we investigate the fixed charges and interface trap states in C–H diamond MOSFETs by using different gate dielectric processes. The devices use Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> as gate dielectrics that are deposited via atomic layer deposition (ALD) at 80 °C and 300 °C, respectively, and their <jats:italic>C</jats:italic>–<jats:italic>V</jats:italic> and <jats:italic>I</jats:italic>–<jats:italic>V</jats:italic> characteristics are comparatively investigated. Mott–Schottky plots (1/<jats:italic>C</jats:italic> <jats:sup>2</jats:sup>–<jats:italic>V</jats:italic> <jats:sub>G</jats:sub>) suggest that positive and negative fixed charges with low density of about 10<jats:sup>11</jats:sup> cm<jats:sup>−2</jats:sup> are located in the 80-°C- and 300-°C deposition Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> films, respectively. The analyses of direct current (DC)/pulsed <jats:italic>I</jats:italic>–<jats:italic>V</jats:italic> and frequency-dependent conductance show that the shallow interface traps (0.46 eV–0.52 eV and 0.53 eV–0.56 eV above the valence band of diamond for the 80-°C and 300-°C deposition conditions, respectively) with distinct density (7.8 × 10<jats:sup>13</jats:sup> eV<jats:sup>−1</jats:sup>⋅cm<jats:sup>−2</jats:sup>–8.5 × 10<jats:sup>13</jats:sup> eV<jats:sup>−1</jats:sup>⋅cm<jats:sup>−2</jats:sup> and 2.2 × 10<jats:sup>13</jats:sup> eV<jats:sup>−1</jats:sup>⋅cm<jats:sup>−2</jats:sup>–5.1 × 10<jats:sup>13</jats:sup> eV<jats:sup>−1</jats:sup>⋅cm<jats:sup>−2</jats:sup> for the 80-°C- and 300-°C-deposition conditions, respectively) are present at the Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>/C–H diamond interface. Dynamic pulsed <jats:italic>I</jats:italic>–<jats:italic>V</jats:italic> and capacitance dispersion results indicate that the ALD Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> technique with 300-°C deposition temperature has higher stability for C–H diamond MOSFETs.</jats:p>

<jats:p>The terahertz (THz) vortex beam generators are designed and theoretically investigated based on single-layer ultra-thin transmission metasurfaces. Noncontinuous phase changes of metasurfaces are obtained by utilizing Pancharatnam–Berry phase elements, which possess different rotation angles and are arranged on two concentric rings centered on the origin. The circularly polarized incident THz beam could be turned into a cross-polarization transmission wave, and the orbital angular momentum (OAM) varies in value by <jats:italic>lℏ</jats:italic>. The <jats:italic>l</jats:italic> values change from ± 1 to ± 5, and the maximal cross-polarization conversion efficiency that could be achieved is 23%, which nearly reaches the theoretical limit of a single-layer structure. The frequency range of the designed vortex generator is from 1.2 THz to 1.9 THz, and the generated THz vortex beam could keep a high fidelity in the operating bandwidth. The propagation behavior of the emerged THz vortex beam is analyzed in detail. Our work offers a novel way of designing ultra-thin and single-layer vortex beam generators, which have low process complexity, high conversion efficiency and broad bandwidth.</jats:p>

<jats:p>An ordinary differential equation (ODE) model of tumor growth with the effect of tumor-immune interaction and chemotherapeutic drug is presented and studied. By analyzing the existence and stability of equilibrium points, the dynamic behavior of the system is discussed elaborately. The chaotic dynamics can be obtained in our model by equilibria analysis, which show the existence of chaos by calculating the Lyapunov exponents and the Lyapunov dimension of the system. Moreover, the action of the infusion rate of the chemotherapeutic drug on the resulting dynamics is investigated, which suggests that the application of chemotherapeutic drug can effectively control tumor growth. However, in the case of high-dose chemotherapeutic drug, chemotherapy-induced effector immune cells damage seriously, which may cause treatment failure.</jats:p>

<jats:p>A novel vertical InN/InGaN heterojunction tunnel FET with hetero T-shaped gate as well as polarization-doped source and drain region (InN-Hetero-TG-TFET) is proposed and investigated by Silvaco-Atlas simulations for the first time. Compared with the conventional physical doping TFET devices, the proposed device can realize the P-type source and N-type drain region by means of the polarization effect near the top InN/InGaN and bottom InGaN/InN heterojunctions respectively, which could provide an effective solution of random dopant fluctuation (RDF) and the related problems about the high thermal budget and expensive annealing techniques due to ion-implantation physical doping. Besides, due to the hetero T-shaped gate, the improvement of the on-state performance can be achieved in the proposed device. The simulations of the device proposed here in this work show <jats:italic>I</jats:italic> <jats:sub>ON</jats:sub> of 4.45 × 10<jats:sup>−5</jats:sup> A/μm, <jats:italic>I</jats:italic> <jats:sub>ON</jats:sub>/<jats:italic>I</jats:italic> <jats:sub>OFF</jats:sub> ratio of 10<jats:sup>13</jats:sup>, and <jats:italic>SS</jats:italic> <jats:sub>avg</jats:sub> of 7.5 mV/dec in InN-Hetero-TG-TFET, which are better than the counterparts of the device with a homo T-shaped gate (InN-Homo-TG-TFET) and our reported lateral polarization-induced InN-based TFET (PI-InN-TFET). These results can provide useful reference for further developing the TFETs without physical doping process in low power electronics applications.</jats:p>

<jats:p>This article investigates an improved 4H-SiC trench gate metal–oxide–semiconductor field-effect transistor (MOSFET) (UMOSFET) fitted with a super-junction (SJ) shielded region. The modified structure is composed of two n-type conductive pillars, three p-type conductive pillars, an oxide trench under the gate, and a light n-type current spreading layer (NCSL) under the p-body. The n-type conductive pillars and the light n-type current spreading layer provide two paths to and promote the diffusion of a transverse current in the epitaxial layer, thus improving the specific on-resistance (<jats:italic>R</jats:italic> <jats:sub>on,sp</jats:sub>). There are three p-type pillars in the modified structure, with the p-type pillars on both sides playing the same role. The p-type conductive pillars relieve the electric field (<jats:italic>E</jats:italic>-field) in the corner of the trench bottom. Two-dimensional simulation (silvaco TCAD) indicates that <jats:italic>R</jats:italic> <jats:sub>on,sp</jats:sub> of the modified structure, and breakdown voltage (<jats:italic>V</jats:italic> <jats:sub>BR</jats:sub>) are improved by 22.2% and 21.1% respectively, while the maximum figure of merit (<jats:inline-formula> <jats:tex-math> <?CDATA ${\rm{FOM}}={V}_{{\rm{BR}}}^{2}/{R}_{{\rm{on}},{\rm{sp}}}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mi mathvariant="normal">FOM</mml:mi> <mml:mo>=</mml:mo> <mml:msubsup> <mml:mi>V</mml:mi> <mml:mrow> <mml:mi mathvariant="normal">BR</mml:mi> </mml:mrow> <mml:mn>2</mml:mn> </mml:msubsup> <mml:mo>/</mml:mo> <mml:msub> <mml:mi>R</mml:mi> <mml:mrow> <mml:mi mathvariant="normal">on</mml:mi> <mml:mo>,</mml:mo> <mml:mi mathvariant="normal">sp</mml:mi> </mml:mrow> </mml:msub> </mml:mrow> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cpb_30_5_058502_ieqn1.gif" xlink:type="simple" /> </jats:inline-formula>) is improved by 79.0%. Furthermore, the improved structure achieves a light smaller low gate-to-drain charge (<jats:italic>Q</jats:italic> <jats:sub>gd</jats:sub>) and when compared with the conventional UMOSFET (conventional-UMOS), it displays great advantages for reducing the switching energy loss. These advantages are due to the fact that the p-type conductive pillars and n-type conductive pillars configured under the gate provide a substantial charge balance, which also enables the charge carriers to be extracted quickly. In the end, under the condition of the same total charge quantity, the simulation comparison of gate charge and OFF-state characteristics between Gauss-doped structure and uniform-doped structure shows that Gauss-doped structure increases the <jats:italic>V</jats:italic> <jats:sub>BR</jats:sub> of the device without degradation of dynamic performance.</jats:p>

<jats:p>A single-stage ring resonator capable of introducing six modes within the ultra-wideband (UWB) passband is presented. The sextuple-mode resonator consists of three rings and three sets of stepped-impedance open stubs. Based on this sextuple-mode resonator, a UWB filter fed by the interdigital-coupling line (ICL) is designed. And we propose a two-round interpolation method to obtain the filter’s initial dimensions. The designed filter is fabricated on a double-sided YBCO/MgO/YBCO high-temperature superconducting (HTS) thin film for demonstration. The experimental results show that this UWB filter produces eight resonances in the passband eventually, which effectively improves the in-band reflection and the band-edge steepness. Moreover, the upper stopband performance is enhanced due to the transmission zeros (TZs) generated by the stepped-impedance open stubs and the ICL structure. The measured good performance verifies the practicability of the two-round interpolation approach, which can also be extended to other odd–even-mode filter designs.</jats:p>

<jats:p>The era of information explosion is coming and information need to be continuously stored and randomly accessed over long-term periods, which constitute an insurmountable challenge for existing data centers. At present, computing devices use the von Neumann architecture with separate computing and memory units, which exposes the shortcomings of “memory bottleneck”. Nonvolatile memristor can realize data storage and in-memory computing at the same time and promises to overcome this bottleneck. Phase-change random access memory (PCRAM) is called one of the best solutions for next generation non-volatile memory. Due to its high speed, good data retention, high density, low power consumption, PCRAM has the broad commercial prospects in the in-memory computing application. In this review, the research progress of phase-change materials and device structures for PCRAM, as well as the most critical performances for a universal memory, such as speed, capacity, and power consumption, are reviewed. By comparing the advantages and disadvantages of phase-change optical disk and PCRAM, a new concept of optoelectronic hybrid storage based on phase-change material is proposed. Furthermore, its feasibility to replace existing memory technologies as a universal memory is also discussed as well.</jats:p>

<jats:p>Despite anionic doping has been widely implemented to increase the visible light activity of TiO<jats:sub>2</jats:sub>, it often gives rise to a dramatical anodic shift in current onset potential. Herein, we show an effective method to achieve the huge cathodic shift of TiO<jats:sub>2</jats:sub> photoanode with significantly enhanced visible light photo-electrochemical activity by nitrogen/cobalt co-implantation. The nitrogen/cobalt co-doped TiO<jats:sub>2</jats:sub> nanorod arrays (N/Co-TiO<jats:sub>2</jats:sub>) exhibit a cathodic shift of 350 mV in onset potential relative to only nitrogen-doped TiO<jats:sub>2</jats:sub> (N-TiO<jats:sub>2</jats:sub>). Moreover, the visible-light (<jats:italic>λ</jats:italic> &gt; 420 nm) photocurrent density of N/Co-TiO<jats:sub>2</jats:sub> reaches 0.46 mA/cm<jats:sup>2</jats:sup>, far exceeding 0.07 mA/cm<jats:sup>2</jats:sup> in N-TiO<jats:sub>2</jats:sub> at 1.23 V <jats:italic>versus</jats:italic> reversible hydrogen electrode (RHE). Systematic characterization studies demonstrate that the enhanced photo-electrochemical performance can be attributed to the surface synergic sputtering of high-energy nitrogen/cobalt ions.</jats:p>

<jats:p>Gaussian network model (GNM) is an efficient method to investigate the structural dynamics of biomolecules. However, the application of GNM on RNAs is not as good as that on proteins, and there is still room to improve the model. In this study, two novel approaches, named the weighted GNM (wGNM) and the force-constant-decayed GNM (fcdGNM), were proposed to enhance the performance of ENM in investigating the structural dynamics of RNAs. In wGNM, the force constant for each spring is weighted by the number of interacting heavy atom pairs between two nucleotides. In fcdGNM, all the pairwise nucleotides were connected by springs and the force constant decayed exponentially with the separate distance of the nucleotide pairs. The performance of these two proposed models was evaluated by using a non-redundant RNA structure database composed of 51 RNA molecules. The calculation results show that both the proposed models outperform the conventional GNM in reproducing the experimental <jats:italic>B</jats:italic>-factors of RNA structures. Compared with the conventional GNM, the Pearson correlation coefficient between the predicted and experimental <jats:italic>B</jats:italic>-factors was improved by 9.85% and 6.76% for wGNM and fcdGNM, respectively. Our studies provide two candidate methods for better revealing the dynamical properties encoded in RNA structures.</jats:p>

<jats:p>The resistive random access memory (RRAM) has stimulated a variety of promising applications including programmable analog circuit, massive data storage, neuromorphic computing, etc. These new emerging applications have huge demands on high integration density and low power consumption. The cross-point configuration or passive array, which offers the smallest footprint of cell size and feasible capability of multi-layer stacking, has received broad attention from the research community. In such array, correct operation of reading and writing on a cell relies on effective elimination of the sneaking current coming from the neighboring cells. This target requires nonlinear <jats:italic>I</jats:italic>–<jats:italic>V</jats:italic> characteristics of the memory cell, which can be realized by either adding separate selector or developing implicit build-in nonlinear cells. The performance of a passive array largely depends on the cell nonlinearity, reliability, on/off ratio, line resistance, thermal coupling, etc. This article provides a comprehensive review on the progress achieved concerning 3D RRAM integration. First, the authors start with a brief overview of the associative problems in passive array and the category of 3D architectures. Next, the state of the arts on the development of various selector devices and self-selective cells are presented. Key parameters that influence the device nonlinearity and current density are outlined according to the corresponding working principles. Then, the reliability issues in 3D array are summarized in terms of uniformity, endurance, retention, and disturbance. Subsequently, scaling issue and thermal crosstalk in 3D memory array are thoroughly discussed, and applications of 3D RRAM beyond storage, such as neuromorphic computing and CMOL circuit are discussed later. Summary and outlooks are given in the final.</jats:p>