Planar Architecture Research Articles

Mechanism for Vipp1 spiral formation, ring biogenesis, and membrane repair

Abstract The ESCRT-III-like protein Vipp1 couples filament polymerization with membrane remodeling. It assembles planar sheets as well as 3D rings and helical polymers, all implicated in mitigating plastid-associated membrane stress. The architecture of Vipp1 planar sheets and helical polymers remains unknown, as do the geometric changes required to transition between polymeric forms. Here we show how cyanobacterial Vipp1 assembles into morphologically-related sheets and spirals on membranes in vitro. The spirals converge to form a central ring similar to those described in membrane budding. Cryo-EM structures of helical filaments reveal a close geometric relationship between Vipp1 helical and planar lattices. Moreover, the helical structures reveal how filaments twist—a process required for Vipp1, and likely other ESCRT-III filaments, to transition between planar and 3D architectures. Overall, our results provide a molecular model for Vipp1 ring biogenesis and a mechanism for Vipp1 membrane stabilization and repair, with implications for other ESCRT-III systems.

High-coherence quantum acoustics with planar superconducting qubits

Quantum acoustics is an emerging platform for hybrid quantum technologies enabling quantum coherent control of mechanical vibrations. High-overtone bulk acoustic resonators (HBARs) represent an attractive mechanical implementation of quantum acoustics due to their potential for exceptionally high mechanical coherence. Here, we demonstrate an implementation of high-coherence HBAR quantum acoustics integrated with a planar superconducting qubit architecture, demonstrating an acoustically induced-transparency regime of high cooperativity and weak coupling, analogous to the electrically induced transparency in atomic physics. Demonstrating high-coherence quantum acoustics with planar superconducting devices enables interesting applications for acoustic resonators in quantum technologies.

An efficient and improved algorithm for generating an equivalent planar architecture of the data vortex switch

The data vortex (DV) switch was originally designed as an all optical interconnection network for high performance computing (HPC) applications. It was highly scalable with low latency and high throughput, compared to traditional switches used for optical packet switching (OPS) and HPC applications. The equivalent planar (chained MIN) model of the DV, proposed in previous literature, is a planar diagrammatic conversion of a 3-D model of the DV network. In this paper, we will focus on exploring a new, efficient and improved generalized algorithm that enables the arrangement of routing pathways to be implemented as an equivalent planar architecture (EPA, chained MIN) of a DV to find all possible routes between each source and target node pair. The original 3-D architecture of any size can be converted to a planar structure more simply by using the new generalized equivalent planar architecture (EPA) algorithm. To verify the proposed EPA algorithm, it was tested with different input traffic loads and network sizes while keeping the active angle ‘A’ constant. Network performance parameters, including injection rate (throughput) and latency (mean hops), obtained from simulation results are also provided to confirm the validity of the proposed EPA algorithm. This new algorithm is versatile, simple and can be applied to networks of various sizes.

A singlet-triplet hole-spin qubit in MOS silicon

Holes in silicon quantum dots are promising for spin qubit applications due to the strong intrinsic spin-orbit coupling. The spin-orbit coupling produces complex hole-spin dynamics, providing opportunities to further optimise spin qubits. Here, we demonstrate a singlet-triplet qubit using hole states in a planar metal-oxide-semiconductor double quantum dot. We demonstrate rapid qubit control with singlet-triplet oscillations up to 400 MHz. The qubit exhibits promising coherence, with a maximum dephasing time of 600 ns, which is enhanced to 1.3 μs using refocusing techniques. We investigate the magnetic field anisotropy of the eigenstates, and determine a magnetic field orientation to improve the qubit initialisation fidelity. These results present a step forward for spin qubit technology, by implementing a high quality singlet-triplet hole-spin qubit in planar architecture suitable for scaling up to 2D arrays of coupled qubits.

One-Pot Sustainable Synthesis of Highly Substituted Pyrimidines via Acceptorless Dehydrogenative Annulation of Alcohols Using Pincer Ni(II)-NNS Catalysts.

We report an efficient and sustainable synthesis of highly substituted pyrimidines promoted by nickel(II)-NNS pincer-type complexes via acceptorless dehydrogenative annulations of readily available alcohols, malononitrile, and guanidine/benzamidine salt under eco-friendly conditions for the first time. Different sets of Ni(II) complexes (C1-C3) encapsulated in NNS pincer-type thiosemicarbazone ligands have been synthesized and authenticated by analytical and spectroscopic (Fourier transform infrared, nuclear magnetic resonance, and high-resolution mass spectrometry) techniques. The solid state three-dimensional structure of a representative complex (C2) has been determined with the aid of single crystal XRD analysis and confirms a square planar architecture around the nickel ion. Further, the well-defined Ni(II) complexes have been employed as efficient catalysts for the fabrication of a wide range of 4-aminopyrimidine-5-carbonitrile derivatives (33 examples) from readily available alcohols with suitable coupling partners such as malononitrile and guanidine/benzamidine under eco-friendly conditions. The current catalytic approach affords maximum yields up to 95% utilizing 3 mol % catalyst loading and water/hydrogen as the only byproduct. A feasible catalytic pathway has been proposed based on the different control experiment reactions, which clearly indicate that the coupling reaction proceeds via aldehyde and benzylidenemalononitrile intermediates. The practicability of the current protocol has been demonstrated by the large-scale synthesis of one of the products, 4-amino-2,6-diphenylpyrimidine-5-carbonitrile, and a short synthesis of a cytosine antifungal analogue.

Columnar self-assembled heteroatom bay-annulated perylene bisimide as passivating layer for high performance perovskite solar cells

The interfaces within Perovskite solar cells (PSCs) are imperative for regulating defects, managing carrier dynamics, preventing ion migration, optimizing energy band alignment, and controlling morphology. The interfaces amidst the absorber layer and the hole transport layer (HTL) pose challenges related to ineffective charge extraction and charge recombination, necessitating enhancement. Spiro-OMeTAD is commonly utilized as p-type material in the HTL of planar architecture, entailing the inclusion of diverse additives to enhance solar cell efficiency, which can restrict device performance and stability. Herein, we explore the influence of a discotic liquid crystalline (DLCs) based semiconductor, a heteroatom bay-annulated perylene bisimide (PBI-SeO10), which is derived from tri-n-alkoxy anilines. Our study examines the function of PBI-SeO10 as an interfacial passivation layer within the perovskite/Spiro-OMeTAD interface, assessing its effects on both device performance and stability. Our results indicate that integrating PBI-SeO10 as a surface passivation layer not only aids in effective hole extraction from the perovskite layer but also substantially diminishes defects, leading to an improvement in overall device performance by approximately 7 %. Furthermore, PBI-SeO10 passivation also reduces ionic/molecular species diffusion into the device and provides good moisture resistivity leading to improved device stability.

Tetrahedral Structure Based on Triphenylgermanium for Quenching‐Resistant Multi‐Resonance Thermally Activated Delayed Fluorescence Emitters

AbstractThe rigid planar architecture of multiple resonance thermally activated delayed fluorescence (MR‐TADF) molecules employing boron/nitrogen (B/N) frameworks typically results in severe aggregation‐caused quenching (ACQ) and spectral broadening. Herein, a steric modification strategy is proposed by incorporating a tetrahedral architecture of triphenylgermanium (TPhGe) into the para‐position of B/N/N, B/N/O, and B/N/S frameworks for the first time, formed three MR‐TADF emitters, BNNGe, BNOGe, and BNSGe, with narrowband emissions ranging from bluish‐green to pure blue. Consequently, these emitters exhibit high photoluminescence quantum yields of > 90% in doped films. Organic light‐emitting diodes (OLEDs) based on BNNGe, BNOGe, and BNSGe demonstrate impressive maximum external quantum efficiencies (EQEmaxs) of 30.1% to 15.5%, and 20.7%, respectively. The unique tetrahedral TPhGe moiety, with its bulky size conformation, effectively separates adjacent MR‐TADF molecules, resulting in efficient luminescence across a broad range of doping concentrations (5–30 wt%) in doped films, thereby successfully suppressing the ACQ in devices. Furthermore, OLEDs containing BNSGe display low‐efficiency roll‐offs because of higher spin‐orbital coupling and reverse intersystem crossing rates of the emitter, attributed to the heavy atom effect. Notably, the device with 5 wt% BNOGe exhibits a pure blue emission peaking at 461 nm, with a narrow full‐width at half‐maximum of 32 nm.

Time-modulated planar frequency diverse array for multi-target detection

The frequency diverse array (FDA) is a very interesting technique in wireless communications. Many research papers are introduced in this field. A lot of them is concerned with linear point sources array. In this paper, a design of a time-modulated planar frequency diverse array architecture is proposed for tracking single or multi-target for the first time. The time-modulation array (TMA) and FDA are combined for detecting single and multi-target. The effectiveness of this combined scheme is demonstrated through simulation results that compared with a point source case to show its superior performance. Authors introduce planar FDA array instead of linear FDA array and realize the planar array using cylindrical dielectric resonator antenna array (CDRA). A planar array consists of 8 × 8 CDRA is used to enable the detection of single target/multi-target. The operating frequency of the antenna is set at 10 GHz, aligning with its applications in the FDA radar. The radiation characteristics of the CDRA antenna element are introduced. High maximum gain of 6 dBi is achieved with a remarkably high efficiency. A set of representative results is reported and analyzed to assess the effectiveness of the proposed approach.

Aerosol jet 3D printing of gold micropillars and their behavior under compressive loads

Three-dimensional (3D) gold microarchitectures such as micropillars, microwires, and microlattices are used in applications such as implantable biosensors, microelectronic circuits, and catalytic devices. Additive Manufacturing (AM) is being explored to create such structures as lithography is more suitable to fabricate 2D or planar architectures. In this work, we use Aerosol Jet (AJ) nanoprinting, a jetting-based AM technique, to demonstrate fabrication of gold micropillars via stacking of nanoparticles and sintering them at temperatures ranging from 300°C to 900°C. We first demonstrate that AJ printed 2D planar films and 3D micropillars exhibit a different grain size distribution, even if they are printed and sintered under identical conditions. This unusual observation indicates that specific AM technique and structures are important in determining their grain structure, which affects their mechanical behavior. The AJ printed 3D gold micropillars are fabricated with aspect ratios up to 10:1 and sintered from lower to higher temperatures, to yield porosities ranging from 15 % to 2 %, and average grain sizes from 25 nm to 1.7 µm, respectively. Micropillars sintered at lower temperatures exhibit a brittle behavior with higher yield strength despite having a higher porosity but with smaller grain sizes, and vice versa. These results indicate that the 3D geometry of AJ printed architectures dictates the grain size evolution, and hence the mechanical properties. Further, the grain size dominates over porosity in determining the micropillar deformation. These results provide important design guidelines for 3D printed microarchitected structures fabricated via jetting-based AM techniques.

Memristors Based on Ni(II)‐tetraaza[14]annulene Complexes: Toward an Unconventional Resistive Switching Mechanism

AbstractIn this work, a family of Ni‐based dibenzotetraaza[14]annulene (dtaa) complexes are investigated for their application in memristors (memory resistors). A series of four Ni(II) complexes with different peripheral substituents of the dtaa ligand are successfully synthesized. Based on these compounds, two‐terminal thin‐film devices are fabricated in planar architecture. Four metals with different work functions are tested: Mg, Cu, Ni, and Au. It is demonstrated that ITO|[Ni(Me4dtaa)]|Cu devices show hysteretic behavior and offer stable, robust, and reproducible switching between high‐ and low‐resistive states. An in‐depth spectroscopic characterization of the Ni complex is performed, using radiation from infrared, through visible and ultraviolet, to tender X‐rays. Operando X‐ray fluorescence spectroscopy is used to monitor redox and structural changes upon the polarization of the studied memristor with the external electric field. Density functional theory calculations are used to better understand the electronic structure of the studied material, as well as structural rearrangement after electron injection that may be responsible for the modulation of electric conductivity. Finding a unique case of filamentary‐type resistive switching involving redox reactions of stationary molecules within a molecular solid is postulated. Yet, the formation of these filaments is not related to any significant configurational changes at the atomic scale.

Evaluation of in-plane architecture in a thermo-electrochemical cell with nanostructured and porous Sb:SnO2 electrodes

Thermo-electrochemical cells (TECs) are able to convert heat into electricity. They are formed by two electrodes (typically Pt) separated by a redox electrolyte (usually 0.4 M aqueous ferro/ferricyanide). The widely adopted architecture of TECs consists of the two electrodes separated by an electrolyte channel. To our knowledge, no studies have been reported exploring a different architecture. Here, we evaluate an alternative configuration, which comprises a substrate with the two electrodes at its ends and with the electrolyte added on the top contacting both electrodes, forming a planar configuration. We explore first the use of the standard Pt electrodes deposited on top of a conductive glass substrate. Then, we replace the Pt by nanostructured and porous Sb-doped SnO2. The planar configurations are compared with their corresponding typical architectures using the common ferro/ferricyanide electrolyte. It was found that the planar TEC with Sb:SnO2 reached a temperature coefficient of 1.76 mV/K, higher than the value obtained in the standard configuration with Sb:SnO2 (1.21 mV/K), and also higher than the planar architecture with Pt electrodes, which showed the typical value for the ferro/ferricyanide electrolyte (1.45 mV/K). As a consequence of this significantly larger value, a 29.7 % higher maximum power output than the planar TEC with Pt was observed. Our study identifies for the first time interesting new features when a planar architecture is employed, opening the door to explore in more detail this alternative configuration in TECs.

Analysis of a Flexible Photoconductor, Manufactured with Organic Semiconductor Films.

This work presents the evaluation of the electrical behavior of a flexible photoconductor with a planar heterojunction architecture made up of organic semiconductor films deposited by high vacuum evaporation. The heterojunction was characterized in its morphology and mechanical properties by scanning electron microscopy and atomic force microscopy. The electrical characterization was carried out through the approximations of ohmic and SCLC (Space-Charge Limited Current) behaviors using experimental J-V (current density-voltage) curves at different voltages and under different light conditions. The optimization of the photoconductor was carried out through annealing and accelerated lighting processes. With these treatments, the Knoop Hardness of the flexible photoconductor has reached a value of 8 with a tensile strength of 5.7 MPa. The ohmic and SCLC approximations demonstrate that the unannealed device has an ohmic behavior, whereas the annealed device has an SCLC behavior, and after the optimization process, an ohmic behavior and a maximum current density of 0.34 mA/mm2 were obtained under blue light. The approximations of the device's electron mobility (μn) and free carrier density (n0) were performed under different light conditions, and the electrical activation energy and electrical gap were obtained for the flexible organic device, resulting in appropriate properties for these applications.

Compiling Quantum Circuits for Dynamically Field-Programmable Neutral Atoms Array Processors

Dynamically field-programmable qubit arrays (DPQA) have recently emerged as a promising platform for quantum information processing. In DPQA, atomic qubits are selectively loaded into arrays of optical traps that can be reconfigured during the computation itself. Leveraging qubit transport and parallel, entangling quantum operations, different pairs of qubits, even those initially far away, can be entangled at different stages of the quantum program execution. Such reconfigurability and non-local connectivity present new challenges for compilation, especially in the layout synthesis step which places and routes the qubits and schedules the gates. In this paper, we consider a DPQA architecture that contains multiple arrays and supports 2D array movements, representing cutting-edge experimental platforms. Within this architecture, we discretize the state space and formulate layout synthesis as a satisfiability modulo theories problem, which can be solved by existing solvers optimally in terms of circuit depth. For a set of benchmark circuits generated by random graphs with complex connectivities, our compiler OLSQ-DPQA reduces the number of two-qubit entangling gates on small problem instances by 1.7x compared to optimal compilation results on a fixed planar architecture. To further improve scalability and practicality of the method, we introduce a greedy heuristic inspired by the iterative peeling approach in classical integrated circuit routing. Using a hybrid approach that combined the greedy and optimal methods, we demonstrate that our DPQA-based compiled circuits feature reduced scaling overhead compared to a grid fixed architecture, resulting in 5.1X less two-qubit gates for 90 qubit quantum circuits. These methods enable programmable, complex quantum circuits with neutral atom quantum computers, as well as informing both future compilers and future hardware choices.

A 3D nanoscale optical disk memory with petabit capacity.

High-capacity storage technologies are needed to meet our ever-growing data demands1,2. However, data centres based on major storage technologies such as semiconductor flash devices and hard disk drives have high energy burdens, high operation costs and short lifespans2,3. Optical data storage (ODS) presents a promising solution for cost-effective long-term archival data storage. Nonetheless, ODS has been limited by its low capacity and the challenge of increasing its areal density4,5. Here, to address these issues, we increase the capacity of ODS to the petabit level by extending the planar recording architecture to three dimensions with hundreds of layers, meanwhile breaking the optical diffraction limit barrier of the recorded spots. We develop an optical recording medium based on a photoresist film doped with aggregation-induced emission dye, which can be optically stimulated by femtosecond laser beams. This film is highly transparent and uniform, and the aggregation-induced emission phenomenon provides the storage mechanism. It can also be inhibited by another deactivating beam, resulting in a recording spot with a super-resolution scale. This technology makes it possible to achieve exabit-level storage by stacking nanoscale disks into arrays, which is essential in big data centres with limited space.

A mechanically robust spiral fiber with ionic-electronic coupling for multimodal energy harvesting.

Wearable electronics are some of the most promising technologies with the potential to transform many aspects of human life such as smart healthcare and intelligent communication. The design of self-powered fabrics with the ability to efficiently harvest energy from the ambient environment would not only be beneficial for their integration with textiles, but would also reduce the environmental impact of wearable technologies by eliminating their need for disposable batteries. Herein, inspired by classical Archimedean spirals, we report a metastructured fiber fabricated by scrolling followed by cold drawing of a bilayer thin film of an MXene and a solid polymer electrolyte. The obtained composite fibers with a typical spiral metastructure (SMFs) exhibit high efficiency for dispersing external stress, resulting in simultaneously high specific mechanical strength and toughness. Furthermore, the alternating layers of the MXene and polymer electrolyte form a unique, tandem ionic-electronic coupling device, enabling SMFs to generate electricity from diverse environmental parameters, such as mechanical vibrations, moisture gradients, and temperature differences. This work presents a design rule for assembling planar architectures into robust fibrous metastructures, and introduces the concept of ionic-electronic coupling fibers for efficient multimodal energy harvesting, which have great potential in the field of self-powered wearable electronics.

Achromatic, planar Fresnel-reflector for a single-beam magneto-optical trap.

We present a novel achromatic, planar, periodic mirror structure for single-beam magneto-optical trapping and demonstrate its use in the first- and second-stage cooling and trapping for different isotopes of strontium. We refer to it as a Fresnel magneto-optical trap (MOT) as the structure is inspired by Fresnel lenses. By design, it avoids many of the problems that arise for multi-color cooling using planar structures based on diffraction gratings, which have been the dominant planar structures to be used for single-beam trapping thus far. In addition to a complex design process and cost-intensive fabrication, diffraction gratings suffer from their inherent chromaticity, which causes different axial displacements of trap volumes for different wavelengths and necessitates trade-offs in their diffraction properties and achievable trap depths. In contrast, the Fresnel-reflector structure presented here is a versatile, easy-to-manufacture device that combines achromatic beam steering with the advantages of a planar architecture. It enables miniaturizing trapping systems for alkaline-earth-like atoms with multiple cooling transitions as well as multi-species trapping in the ideal tetrahedral configuration and within the same volume above the structure. Our design presents a novel approach for the miniaturization of cold-atom systems based on single-beam MOTs and enables the widespread adoption of these systems.

Experimental comparison of planar transformer architectures for half-bridge resonant topology

Power electronics is experiencing a strong growth, driven by industrial demand for applications as diverse as wall adapters and renewable energy. In addition to topologies, semiconductors or control, there is also a need for research in magnetics, such as planar transformers, which are very useful for certain applications where a low converter profile is desired, so that replacing traditional wire transformers has a quantitative advantage in terms of power density and geometry, as well as EMI reduction. In this paper, an experimental comparison of different planar transformer architectures is made, a contrast of the test results is presented. Six possibilities are carried out, dealing with diverse configurations in primary and secondary windings, of which a theoretical estimation of losses is performed. To demonstrate the effect of variations in the proposals, a 100 W prototype converter, with an input voltage range of 320 to 380 V and an output range of 5 to 20 V is developed based on the novel hybrid flyback topology, reaching a maximum efficiency of 97% using GaN semiconductors. With it, a comparison is made in terms of efficiency and common noise between the alternatives.

Utilization of coal mine gas in solid oxide fuel cells: A performance evaluation

The possibility and regimes of coal mine gas utilization in solid oxide fuel cells (SOFCs) without external methane reforming were appraised using a short-stack of two membrane-electrode assemblies with the planar electrolyte-supported architecture. The stack fueled by model coal mine gas, namely 59 % CH4 - 5 % CO2 – 36 % N2 mixture humidified at 343–363 K, demonstrated a stable operation during approximately 170 h at 1123 K when the fuel humidity was higher than 38 vol%. The performance decreased with increasing steam concentration and was lower than that obtained for hydrogen fuel at the same humidity levels. The maximum power density, 157 mW/cm2 at the current density of 284 mA/cm2, was observed for 38 % humidity close to the thermodynamic limit where carbon nanotube formation may start at the SOFC anode. Decreasing water vapor partial pressure resulted in a fast degradation, accompanied with increasing ohmic and polarization losses. Subsequent microscopic analysis confirmed that these effects are indeed associated with the carbon deposition. Beyond the coking domain, the current vs. voltage dependencies of the SOFC stack can be described by a simplified model assuming that the anode kinetics is essentially governed by the electrochemical oxidation of hydrogen.

Morphological investigation and 3D simulation of plasmonic nanostructures to improve the efficiency of perovskite solar cells

The light absorption process is a key factor in improving the performance of perovskite solar cells (PSCs). Using arrays of metal nanostructures on semiconductors such as perovskite (CH3NH3PbI3), the amount of light absorption in these layers is significantly increased. Metal nanostructures have been considered for their ability to excite plasmons (collective oscillations of free electrons). Noble metal nanoparticles placed inside solar cells, by increasing the scattering of the incident light, effectively increase the optical absorption inside PSCs; this in turn increases the electric current generated in the photovoltaic device. In this work, by calculating the cross-sectional area of dispersion and absorption on gold (Au) nanoparticles, the effects of the position of nanoparticles in the active layer (AL) and their morphology on the increase of absorption within the PSC are investigated. The optimal position of the plasmonic nanoparticle was obtained in the middle of the AL using a three-dimensional simulation method. Then, three different morphologies of nano-sphere, nano-star and nano-cubes were investigated, where the short-circuit currents (Jsc) for these three nanostructures were obtained equal to 19.01, 18.66 and 20.03 mA/cm2, respectively. In our study, the best morphology of the nanostructure according to the Jsc value was related to the nano-cube, in which the device power conversion efficiency was equal to 16.20%, which is about 15% better than the PSC with the planar architecture.

Modelling, synthesis, fabrication, and characterization of a novel lead-free organo-inorganic iodide perovskite for photovoltaic application

This work is aimed at modelling, synthesizing, and characterizing of a novel lead-free organo-inorganic halide perovskite for photovoltaic application. A planar solar cell device architecture was employed in the fabrication with graphite anode. Thermo-gravimetry analyzer (TGA) was used to determine the thermal stability under nitrogen flow from 20 oC to 870 oC. The TGA result exhibits thermal stability above 200 oC. X-Ray Diffraction (XRD) was used to confirm the crystallinity formation, several peaks were observed with the most prominent peaks at 2Ө = 19.0o, 29.5o, and 33.3o with average crystalline size of 42 nm calculated using Scherrer’s equation. The Field Emission Scan Electron Microscope/Energy Dispersion Spectroscope (FESEM/EDS) results showed a plate-like/cubic structure of hexagonal crystal shapes. These shapes are agglomerated in nature with fine and coarse grains, which might improve the photo-excited electrons diffusion through aggregating the light scattering properties and effective mean path of light of perovskite solar cell. Differential Scanning Calorimetry (DSC) results showed that gradual decomposition of the material can only be visible between 200 oC and 240 oC with the peak at 223.9 oC. The photoluminescence properties of the synthesized perovskites light absorbing layers exhibit a broad band spectrum emission within the range of 340 to 588nm, which is within visible spectrum. The UV-vis spectrum exhibits a strong optical absorption band in the visible region, which extends from 360 nm to 725 nm. The band gap energy was calculated from the plotted Tauc fit and estimated to be 1.99 eV. The J-V of the synthesized material recorded the highest PCE of 4.6 % with a fill factor of 19.56.