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Organic solar cells (OSCs) have emerged as promising candidates for renewable energy harvesting due to their lightweight, flexible, and low‐cost fabrication potential. The efficiency of OSCs is largely determined by the choice of solvents, which significantly affect the film morphology of the active layers, the intermixed donor‐acceptor domains, and overall device performance. Beginning with an introduction to the importance of solvent selection, the screening and classification of solvents, emphasizing their characteristics and classification based on sustainability, solubility, and other additional considerations are explored. Various non‐halogenated solvents, highlighting commonly used aromatic solvents, biomass‐derived solvents, and water/alcohol‐based solvents are explored. The state‐of‐the‐art donor and acceptor materials, focusing on efficient donor materials such as PM6 and D18, and high‐performing Y‐series acceptors are also presented. Strategies for developing high‐performance OSCs processed using non‐halogenated solvents are examined, including solvent engineering with additive and additive‐free approaches, ternary strategies, and layer‐by‐layer techniques. The fabrication of large‐area devices using non‐halogenated solvents is addressed, focusing on blade‐coating, slot‐coating, and other processing techniques. Finally, this review outlines future research directions in the non‐halogenated solvent processing of OSCs, emphasizing the need for continuous innovation to overcome existing limitations and propel OSC technology toward commercial viability. [ABSTRACT FROM AUTHOR]

Lead‐free 0D In‐based organic–inorganic metal halides (OIMHs) have attracted tremendous attention because of their nontoxicity, environmental stability, and excellent photoluminescence properties. However, it remains controversial and unclear whether the luminous division exists in ns2 doping In‐based materials, as the majority of In‐based materials are considered non‐luminous. Herein, a series of Bi3+‐doped (TEA)2InCl5 (TEA = tetraethylammonium) crystals are synthesized and it is determined that the blue emission stemmed from Bi ions. Remarkably, the photoluminescence quantum yield (PLQY) of the blue emission at 469 nm reached 69.69% under 371 nm excitation, exceeding those of previously reported Bi3+‐doped OIMHs. In addition, pristine and Bi3+‐doped compounds exhibited excellent structure and optical stability under humid conditions. This study provides new insights into the photoluminescence properties of In‐based OIMHs, especially regarding the high‐efficiency emission of Bi3+‐doped materials. [ABSTRACT FROM AUTHOR]

Summary: In this paper, an out‐of‐band suppression enhanced high‐efficiency millimeter‐wave (mm‐wave) gallium nitride (GaN) microwave monolithic integrated circuit (MMIC) filtering power amplifier (FPA) is presented. A modified elliptic response bandpass filtering (BPF) output matching network (OMN) is used to achieve low loss and high out‐of‐band rejection. The circuit of the presented BPF OMN is given and its synthesized method is introduced. The simulated S‐parameters show that the OMN has a low‐loss in‐band response and a desired out‐of‐band rejection performance with two transmission zeros (TZs). To demonstrate this idea, a two‐stage 24–28‐GHz GaN MMIC PA is designed and implemented in a 0.15‐μm GaN‐on‐SiC process, with a mask area of 2.4 × 1.0 mm2. Experimental results show that the realized MMIC PA achieves a small signal gain of 18.8 dB from 24 to 28 GHz with ±1.2‐dB gain flatness and 40‐dB rejection at 19.43 and 33.8 GHz. The saturated power‐added efficiency (PAE) is higher than 29% from 24 to 28 GHz, with a peak PAE of 36.3% at 27 GHz. The output power is within the range of 33.8 to 35.6 dBm in the operating band. For a 100‐MHz five‐carrier LTE signal, the PA can achieve ACLR better than −40 dBc over the band with digital predistortion. [ABSTRACT FROM AUTHOR]

The electron transport layer (ETL), perovskite layer, hole transport layer, and electrode layer collectively constitute the perovskite solar cells (PSCs). Each of these layers plays a critical role in the performance of devices. However, there are mismatches in crystal structure and energy levels between ETL materials and the perovskite layer, resulting in numerous defects at their interface. In this study, multifunctional organic molecule called phosphorylcholine chloride is designed to modify the interface between SnO2 and perovskite layer. This modification serves to both reduce oxygen vacancy defects in the SnO2 and passivate defects in the perovskite layer. Consequently, the conductivity and electron mobility of SnO2 are improved, and the higher‐quality of perovskite film is obtained. Ultimately, the optimized PSC device achieves an impressive champion power conversion efficiency (PCE) of 24.34% with minimal hysteresis index. Even after 1200 h of ambient exposure at 25 °C and 25% relative humidity without encapsulation, the device maintains an impressive 91.44% of its initial efficiency. Additionally, a PCE of 22.38% is attained in flexible PSCs. This research will pave the way for the development of low interface defects, high stability as well as high PCE perovskite solar cells. [ABSTRACT FROM AUTHOR]

Benefiting from the abrupt phase changes within subwavelength thicknesses, metasurfaces have been widely applied for lightweight and compact optical systems. Simultaneous broadband and high-efficiency characteristics are highly attractive for the practical implementation of metasurfaces. However, current metasurface devices mostly adopt discrete micro/nano structures, which rarely realize both merits simultaneously. In this paper, dielectric metasurfaces composed of quasi-continuous nanostrips are proposed to overcome this limitation. Via quasi-continuous nanostrips metasurface, a normal focusing metalens and a superoscillatory lens overcoming the diffraction limit are designed and experimentally demonstrated. The quasi-continuous metadevices can operate in a broadband wavelength ranging from 450 nm to 1000 nm and keep a high power efficiency. The average efficiency of the fabricated metalens reaches 54.24%, showing a significant improvement compared to the previously reported metalenses with the same thickness. The proposed methodology can be easily extended to design other metadevices with the advantages of broadband and high-efficiency in practical optical systems.

In today's era of increasing energy constraints, harnessing the power of electromagnetic waves and converting them into directly usable energy has great potential in the field of renewable energy. This paper presents a highly efficient electromagnetic energy harvester with wide operation angles based on metasurface. The metasurface unit comprises four rotated copper rings plated on a Rogers RT5880 substrate. This unique design incorporates a 3.6 kΩ resistor within each of the four-cornered rotating metal rings, effectively emulating the input impedance circuit of a rectifier. Simulation results reveal that the metasurface achieves a remarkable electromagnetic wave harvesting efficiency of up to 92.3% at a frequency of 5.85 GHz. Additionally, it exhibits polarization insensitivity, enhancing its versatility and suitability for wide incident angles, which augments its practicality in various environments. The proposed metasurface energy harvester represents a significant advancement in electromagnetic energy collection technology, offering an efficient and reliable energy harvesting solution that contributes to addressing energy shortages and is applicable across multiple scenarios. [ABSTRACT FROM AUTHOR]

This paper studies the influence of the gate voltage of the power amplifier (PA) on the drain current and efficiency. This study proposes a theory of controlling input non‐linearity to improve the efficiency of PAs. The theoretical efficiency of the inverse Class F PA that controls the input nonlinearity is within the range of 77% to 97%. A new design method for the inverse Class F PA reconstructs the design of the load admittance space into a region instead of a point. To verify the validity of the proposed theory, an inverse Class F PA is designed and fabricated using a commercial 10 W GaN high electron mobility transistor (HEMT). Results of the measurement show a high drain efficiency (DE) of 78.5%, an output power of 41.6 dBm, and a large signal gain of 12.1 dB at 1.5 GHz. The overall PA's size is controlled at 80*50 mm2$$ \mathrm{m}{\mathrm{m}}^2 $$. [ABSTRACT FROM AUTHOR]

Multiwavelength metasurfaces with complex-amplitude modulations have attracted great attention due to their unprecedented abilities for electromagnetic wavefront manipulations. In this work, a novel dual-band high-efficiency transmissive complex-amplitude meta-atom is proposed, which is composed of two identical metallic-patterned layers printed on both sides of a substrate. Each metallic layer is perforated with a double-C-shaped split-ring resonator and a single C-slot resonator, which could achieve efficient cross-polarized conversions of over 80% at two operation frequencies under a circular polarization incidence. In addition, an isolation ring is ingeniously positioned between the two resonators to effectively reduce the mutual coupling. By adjusting the rotation angles of the two resonators, 2π phase modulation and amplitude modulation from a maximum value to zero can be individually realized at both frequencies. As a proof-of-concept demonstration, a dual-band meta-hologram is numerically studied and experimentally verified. This proposed method holds great potential across multifunctional applications such as data storage, information encryption, and virtual reality display. [ABSTRACT FROM AUTHOR]

This paper aims to solve large-scale and complex isogeometric topology optimization problems that consume significant computational resources. A novel isogeometric topology optimization method with a hybrid parallel strategy of CPU/GPU is proposed, while the hybrid parallel strategies for stiffness matrix assembly, equation solving, sensitivity analysis, and design variable update are discussed in detail. To ensure the high efficiency of CPU/GPU computing, a workload balancing strategy is presented for optimally distributing the workload between CPU and GPU. To illustrate the advantages of the proposed method, three benchmark examples are tested to verify the hybrid parallel strategy in this paper. The results show that the efficiency of the hybrid method is faster than serial CPU and parallel GPU, while the speedups can be up to two orders of magnitude. Graphic Abstract [ABSTRACT FROM AUTHOR]

Thermally activated delayed fluorescence (TADF) materials that exhibit simultaneously high photoluminescence quantum yield (PLQY), rapid reverse intersystem crossing (RISC), and a high horizontal transition dipole ratio are highly desirable for realizing high‐performance organic light‐emitting diodes (OLEDs). However, achieving this goal remains a formidable challenge due to the stringent molecular design principles involved. Herein, three highly efficient TADF materials based on lactam‐type electron‐acceptors are reported. The inherent rigidity and planar structure of lactam units, along with the ordered molecular arrangement in solid states, contribute to the reduction of nonradiative decay and the high horizontal transition dipole ratio in the optimized TADF emitters. Moreover, through precise control of the alignment of the lowest excited states by adjusting the charge transfer strength, the rate constants for reverse intersystem crossing (kRISC) are dramatically boosted. Consequently, the two optimized emitters exhibit outstanding merits of ultra‐high PLQYs (98% and 99%), high horizontal transition dipole ratios (91% and 87%), and fast RISC (kRISC ≈ 1.7 × 106 s−1). Thanks to these merits, the doped OLEDs achieve excellent performance. The top‐performing device achieve a maximum external quantum efficiency of 34.3%, a peak luminance of 57376 cd m−2, and small efficiency roll‐off. [ABSTRACT FROM AUTHOR]

C-band high-power microwave devices have important application prospects in communication, radar and other fields, and the demand for compact and lightweight devices is becoming more and more urgent in the industrial sector. A C-band high-efficiency coaxial transit-time oscillator (CTTO) with three-cavity buncher and dual-cavity extractor is proposed and investigated in theory and 2.5-dimensional particle-in-cell simulations, which is good for high power microwave generation devices at low frequency towards miniaturization and compactness. In order to avoid the transverse electromagnetic mode (TEM) leaking to the diode region, the reflector is designed and adopted in front of the buncher, which also can pre-modulate the beams and lead to the higher conversion efficiency. In this simulation, the typical performance of the CTTO reveals that microwaves with a power of 1.83 GW are generated at a frequency of 6.37 GHz when the beam voltage and current are 458 kV and 9.6 kA respectively, under a guiding magnetic field of 1.05 T. The corresponding power conversion efficiency is as high as 41.6%. [ABSTRACT FROM AUTHOR]

This paper proposes a design method for designing an ultrawideband and high‐efficiency hybrid extended continuous inverse class‐F power amplifier (PA) based on elliptic low‐pass filtering matching network. This design methodology expands the impedance space by adding free factors to the current equation of traditional inverse class‐F power amplifier (PA). Additionally, an output matching network (OMN) incorporating an elliptical low‐pass filter creates two transmission zeros near the passband and provides a rapid transition to the impedance from passband to stopband. In order to verify the effectiveness and superiority of this design method, an ultrawideband PA working over 0.7–3.7 GHz (136.4%) is designed and fabricated. Over this frequency range, the drain efficiency (DE) is measured as 60.7%–73.4% with the output power of greater than 41 dBm and a large signal gain ranging from 11 to 12.7 dB. [ABSTRACT FROM AUTHOR]

This paper describes a high-frequency shunt feedback amplifier. A new design procedure is presented based on practical design steps as well as theoretical aspects, such as sizing the transistor, stabilisation, and selecting the values of feedback elements. The amplifier is designed and fabricated using 0.15 μm GaAs technology. It operates in the 7–10 GHz frequency range, with a small signal gain of 11.5 $ \pm $ ± 0.5 dB and input and output return losses of less than 6 dB and 7 dB, respectively. Furthermore, for 1 dB and 3 dB output compression points, the maximum measured values are 23.1 dBm and 23.9 dBm, respectively. Besides, the maximum measured value for Power Added Efficiency (PAE) for 1 dB output compression is 27.13% and 48.6% for 3 dB output compression. In addition, the measured Noise Figure (NF) in the frequency band of interest ranges from 3.7 to 4.1 dB. The chip area of the fabricated amplifier is 1.01 mm2. [ABSTRACT FROM AUTHOR]

We proposed a high gain high-efficiency compact metallic resonator antenna operating at even-mode meander line spoof surface plasmon polaritons (MLSSPPs). The high radiation efficiency is caused by the bulk of fields crowded in lossless air near the antenna rather than in lossy dielectric as in conventional dielectric resonator antennas (DRAs). The proposed antenna also exhibits compact size because of its high effective refractive index. A reliable equivalent circuit model is proposed for the design of the resonator antenna with basic mode of half wavelength resonant mode. As an example, a meander-line SSPP antenna is designed, fabricated and measured. Both the simulated and measured results show the advantages of high efficiency and compact volume. In addition, the antenna achieves higher gain and wider relative bandwidth per wavelength cube volume compared with its counterparts. This method provides a good alternative for designing DRAs. [ABSTRACT FROM AUTHOR]

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Benzovindiflupyr (BEN) has emerged as one of the fastest-growing SDHI fungicides in recent years, but it is considered “very highly toxic” to aquatic fish, invertebrates and crustaceans (EC50 or LC50, 0.0035–0.056 mg/L, acute toxicity). The comprehensive study on bioactivity, toxicity, and degradation behaviors of BEN at the enantiomeric level would facilitate the development of a high-efficiency and low-risk application method. The bioactivities of 1S, 4R-(−)-BEN against five target pathogens (Alternaria alternata, Phoma multirostrata, Selerotium rolfsii, Magnaporthe oryzae, and Rhizoctonia solani) (EC50, 0.00562–0.329 mg/L, high-efficiency) were 6.7–1029 times higher than 1R, 4S-(+)-BEN, demonstrating significant enantioselectivity. For Danio rerio, 1S, 4R-(−)-BEN (LC50, 0.0360 mg/L, “very highly toxic”) exhibited higher toxicity than 1 R, 4S-(+)-BEN, but the toxic interaction was concentration addition (TUrac, 0.94), indicating an enhanced toxicity in the presence of 1R, 4S-(+)-BEN. Molecular docking was employed to offer insights at the molecular level and elucidate the factors influencing enantioselectivity. The stronger binding affinity of 1S, 4R-(−)-BEN with SDH was in line with the quantitative experimental findings. The degradation of two BEN enantiomers in four different fruits followed the first-order degradation kinetics equation, and displayed enantioselectivity. The preferential degradation of 1R, 4S-(+)-BEN was found in pears and grapes, while varying enantioselectivity was found at different stages in tomatoes and watermelons. The residual concentrations of BEN in grapes were higher than the EU’s MRL, which in the other three fruits were below the MRLs during the sampling. In conclusion, 1S, 4R-(−)-BEN proved to be the more effective monomer. Utilizing the pure monomer could not only reduce the dosage of racemate by about 44–59 %, but also mitigate the risk of introducing inefficient monomer into the environment (especially for fish).

Abstract Low efficiency and spectral instability caused by the surface defects have been considerable issues for the mixed‐halogen blue emitting perovskite quantum dots light‐emitting diodes (PeQLEDs). Here, an in situ surface passivation to perovskite quantum dots (PeQDs) is realized by introducing the metal cations competitive lattice occupancy assisted with acid‐etching, in which the long‐chain, insulating and weakly bond surface ligands are removed by addition of octanoic acid (OTAC). Meanwhile, the dissolved A‐site cations (Na+) compete with the protonated oleyl amine and are subsequently anchored to the surface vacancies. The preadded lead bromide, acting as inorganic ligands, demonstrates strong bonding to the uncoordinated surface ions. The as‐synthesized PeQDs show the boosted photoluminescence quantum yield (PLQY) and superior stability with longer lifetime. As a result, the PeQLEDs (470 nm) based on the OTAC‐Na PeQDs exhibit an external quantum efficiency of 8.42% in the mixed halogen PeQDs (CsPb(BrxCl1−x)3). Moreover, the device exhibits superior spectra stability with negligible shift. Our competition mechanism in combination with in situ passivation strategy paves a new way for improving the performance of blue PeQLEDs.

A carbazole‐based hole‐transport‐type (p‐type) host, BPhCz, is developed using a nonsymmetrical connection strategy between two identical groups. Two benzimidazole–triazine‐based electron acceptor materials with superior electron transport abilities, namely SFX‐PIM‐TRZ and DSFX‐PIM‐TRZ, are designed to fabricate exciplex‐host systems combined with BPhCz. Exciplexes exhibit excellent carrier transport characteristics and appropriate energy levels and can serve as hosts for green multiple resonance‐induced thermally activated delayed fluorescence (MR‐TADF) devices. Efficient green MR‐TADF organic light‐emitting diodes with high color purity and low efficiency roll‐offs are successfully fabricated using the exciplexes prepared from BPhCz:SFX‐PIM‐TRZ and BPhCz:DSFX‐PIM‐TRZ as hosts, which show low driving voltages of 2.6 and 2.7 V, high maximum external quantum efficiencies (EQEs) of 35.7% and 35.5%, ultrapure green emission with Commission Internationale de L'Eclairage coordinates of (0.27, 0.69) and (0.28, 0.69), and high EQEs of 31% and 30.5% at 1000 cd m−2, respectively. [ABSTRACT FROM AUTHOR]

For a phased‐array antenna system, position mismatches in spacing distances between source's output and antenna arrays' input ports are common. At present, flexible radiofrequency cables are always utilized to electrically connect those two parts, which will result in the reduced integration. To tackle this problem, a low‐profile aperture converter array (ACA) is first proposed, which is applied between a microwave source and antenna arrays. Each stripline‐structured channel of the ACA is composed of the signal lines with different routing shapes to achieve nearly the same phase shift. In this study, a high‐power and high‐efficiency 16‐channel ACA is designed, fabricated and measured at X‐band. Experimental results show that it meets the requirement of 5‐kW pulse wave input, and the power transfer efficiency of each channel is more than 93.8%. Furthermore, its profile is only 0.42 λ0 ${\lambda }_{0}$ at 9 GHz, which is favorable to transforming the integration of the whole system. [ABSTRACT FROM AUTHOR]

This paper presents a compact coaxial-waveguide four-way power divider with high efficiency, low insertion loss, and high isolation. To improve power capacity and facilitate fabrication, the power divider adopts a square coaxial-waveguide structure. Furthermore, to enhance isolation performance, a star-shape isolation microstrip circuit is utilized, connected with four resistors. The measurements demonstrate that the return loss of the sum port is greater than 20 dB from 7.8 GHz to 10 GHz, while the return loss of the output ports is greater than 20 dB from 7.25 to 9.18 GHz. The insertion loss is approximately 0.3 ± 0.1 dB and the isolation is greater than 23 dB from 7 GHz to 10 GHz. The combining efficiency is over 92%. Additionally, the power divider has a compact size of approximately $0.8\lambda \times 0.8\lambda \times 0.19\lambda $ 0.8 λ × 0.8 λ × 0.19 λ for the central frequency of 8.5 GHz. [ABSTRACT FROM AUTHOR]

Summary In this paper, a systematic research of the effects of second source harmonics caused by gate‐source capacitance in the design of a series of continuous mode (SCM) power amplifiers (PAs) is first presented. The research results show that, compared to the conventional SCMs that require the input second harmonic to be short circuited, SCMs under the impact of input nonlinearity have a more flexible input second harmonic manipulation space, and to further improve and maintain the performance of PAs in wideband operations, a new impedance design space is explored through analysis. For practical validation, SCMs PA considering the effects of the input nonlinearity is designed and fabricated with a 10‐W gallium nitride (GaN) device, acquiring 39.1–42 dBm output power and 60.6–71.5% drain efficiency (DE) performance at a 3 dB gain compression level operating over the 0.5–3.5 GHz frequency range with a relative bandwidth of 150%. [ABSTRACT FROM AUTHOR]

Retroreflective gratings serve as fundamental optical elements in nanophotonics, with polarization-independent diffraction efficiency being one of the critical parameters for assessing their performance. In the far-infrared spectral range, traditional retroreflective gratings typically refer to metal echelette gratings, but their diffraction efficiency cannot approach 100% due to metal absorption. In the visible and near-infrared spectral ranges, metal echelette gratings have gradually been replaced by all-dielectric metasurfaces because dielectric materials exhibit negligible absorption at specific wavelengths. However, there is still a lack of relevant research in the far-infrared range, mainly due to the weak control capability of the existing devices over the polarization-independent phase. Here, we propose a kind of all-dielectric retroreflective metasurface composed of asymmetric pillars and freely tunable aperiodic multilayer films. The pillar structure can achieve polarization insensitivity, and the insufficient modulation capability of the dielectric materials can be compensated for by aperiodic Ge/ZnS films. The designed metasurface achieves the diffraction efficiency by RCWA, with the maximum larger than 99% and the overall reaching 95% (9.3–9.6 µm). We have provided detailed explanations of the design methodology and fabrication process. Our work lays the groundwork for further exploration and application of far-infrared lasers. [ABSTRACT FROM AUTHOR]

In this article, multiobjecive Bayesian optimization (MBO) with a non‐penalization strategy is proposed to design a 15‐dB back‐off high‐efficiency load modulated balanced amplifier (LMBA). Applying the proposed method, the output matching networks of the LMBA are optimized to achieve proper load modulation behaviors that providing good performance. To verify the proposed method, a 2.0‐GHz LMBA is designed and measured. Experimental results show that LMBA achieves an output power of 44.5 dBm with a gain higher than 6.6 dB at saturation. The measured drain efficiency (DE)/power‐added efficiency (PAE) are 67%/52% at saturation, 54%/43% at 9‐dB back‐off, and 52%/46% at 15‐dB back‐off, respectively. Tested with 20‐MHz signal with 10‐dB peak‐to‐average power ratio (PAPR) and a 256‐quadrature amplitude modulation (QAM) scheme, the LMBA achieves adjacent channel leakage ratio (ACLR) levels of −46.7/−47.5 dBc and an error vector magnitude (EVM) of 1.2% after digital predistortion. [ABSTRACT FROM AUTHOR]

[Display omitted] • The continuously welded 2D nano-networks were constructed based on hierarchical phase separation. • The impact of the polymer concentrations on the phase behavior in the ternary system was investigated. • The synergistic effect of sieving and adhesion was used to capture the PM. • The interaction between PM and PVB nanowires was proposed. • The spider web-inspired membrane shows excellent air filtration performance and stable long-term recycling capacity. Air pollution has garnered significant worldwide attention; however, the existing air filtration materials still suffer from issues related to monotonous structure and the inherent trade-off between PM rejection and air permeability. Herein, a spider web-inspired composite membrane with continuous monolayer structured 2D nano-networks tightly welded on nanofibers in the electrospun membrane scaffold is designed via a hierarchical phase separation strategy. The resultant biomimetic hierarchical-structured membranes possess the integrated features of hierarchical multiscale structures of 2D ultrafine networks composed of nanowires with a diameter of 31 nm self-assembled by nanoparticles, exceptional characteristics involving small average aperture, extremely low network thickness, high porosity and promising pore channel connectivity, combined with rich surface polar functional groups (3.02D dipole moment). Consequently, the composite membrane exhibits a high PM 0.3 capture efficiency of 99.6 % and low pressure drop of 58.8 Pa, less than 0.06 % of atmosphere pressure, with outstanding long-term PM 2.5 recycling filtration performance. The hierarchical phase separation–driven 2D nano-networks construction strategy, by virtue of their feasibility and tunability, holds great promise for widespread application across diverse membrane-related domains for air filtration. [ABSTRACT FROM AUTHOR]

In today’s era of increasing energy constraints, harnessing the power of electromagnetic waves and converting them into directly usable energy has great potential in the field of renewable energy. This paper presents a highly efficient electromagnetic energy harvester with wide operation angles based on metasurface. The metasurface unit comprises four rotated copper rings plated on a Rogers RT5880 substrate. This unique design incorporates a 3.6 kΩ resistor within each of the four-cornered rotating metal rings, effectively emulating the input impedance circuit of a rectifier. Simulation results reveal that the metasurface achieves a remarkable electromagnetic wave harvesting efficiency of up to 92.3% at a frequency of 5.85 GHz. Additionally, it exhibits polarization insensitivity, enhancing its versatility and suitability for wide incident angles, which augments its practicality in various environments. The proposed metasurface energy harvester represents a significant advancement in electromagnetic energy collection technology, offering an efficient and reliable energy harvesting solution that contributes to addressing energy shortages and is applicable across multiple scenarios.

We present a salient object detection method in this paper. It uses a lightweight network based on multi-scale information aggregation (MIA) module and bidirectional cross-stage feature fusion (BCF2) module to speed up the reasoning process. Besides, it designs a stepwise coupling optimization strategy based on positive-incentive pseudo label to alleviate the miss detection rate for small objects and the false detection rate for big objects. It is worth noting that the positive-incentive pseudo label generation mechanism can increase the ratio of salient pixels in small objects to alleviate the severe category imbalance problem, while the stepwise coupling optimization strategy can avoid the misguidance of pseudo label to big objects. In addition, the experimental results demonstrate that our method is fairly efficient, its frame rate in reasoning phase reaches 275.6 FPS on NVIDIA RTX3080 GPU when the input resolution is set to $336\times 336$ .

In this study, a highly efficient harmonic suppressed dual-band power amplifier (PA) for harmonic radar systems is proposed. The proposed PA incorporates a harmonic-controlled dual-band matching network (HCDMN) comprising $\lambda $ /4 open stubs at the second-harmonic frequencies and series transmission lines. The HCDMN can effectively suppress unwanted second-harmonic signals and control the fundamental and second harmonic impedances to operate in continuous class-F1 mode at two operating frequencies. The implemented PA has dimensions of 75.3 mm $\times 54.9$ mm. Measurement results demonstrate that the PA achieves an exceptional performance, with peak drain efficiencies (DEs) of 81.5 and 71.8 %, saturated output powers of 40.3 and 41.9 dBm, and second harmonic levels of −75.6 and −49.4 dBc at 2.3 and 3.35 GHz, respectively. Furthermore, the DEs remain above 65 % in the two frequency bands of 2.2–2.5 and 3.3–3.45 GHz.

The DC microgrid with energy storage cells has strong stability, simple control, and a convenient power supply for DC loads, increasingly becoming the grid-connected structure of distributed generation systems. This paper presents an isolated high voltage gain soft-switching dc-dc converter suitable for DC microgrid applications. The converter comprises a dual-switch quasi-z-source network, multiplier voltage cell, and transformer. It has advantages such as high voltage gain, zero voltage switching (ZVS) of switches, zero voltage zero current switching (ZVZCS) turn-on and turn-off of diodes, and low input ripple current. The converter can achieve high voltage gain with an appropriate duty cycle and transformer turns ratio, reducing leakage inductance of transformer, which decreases the power loss and voltage spike of switch. Soft-switching of active devices increases the efficiency and decreases the output voltage ripples of the converter. The steady-state characteristics of the converter, voltage and current stress of components, the efficiency of the converter, and the selection of converter parameters are analyzed in detail. Finally, a 200 W experimental prototype is built in the laboratory for experimental verification, and the experimental results are consistent with the theoretical analysis.

This paper presents a design method for a watt-level high-efficiency broadband power amplifier (BPA) with a generalized parallel-circuit (PC) Class-E model. A combination of the single-reactance compensation technique (S-RCT) and Chebyshev low-pass (LP) impedance matching network (MN) is used for achieving PA’s broadband characteristics. The analytical expression of the operation and power loss mechanisms of PC Class-E PA, which includes the effects of a finite DC-feed inductance, transistor on-resistance, and a broadband MN, is elaborated. As an example, a highly-efficient broadband PC (BPC) Class-E PA operating at 12 V drain supply voltage is implemented and verified experimentally. The designed PA exhibits high-efficiency characteristics of 82.15%-86.3% drain efficiency (DE) and 36.92-38.57 dBm output power ( $P_{out}$ ) with 19.95-23.11 dB power gain in the band from 7 MHz to 9.4 MHz. The measured results show good agreement with the theoretical and simulated results.

A novel dual-port multiple-input-multiple-output (MIMO) antenna arrangement is introduced for attaining quasi-omnidirectional circular polarization (OCP) towards device-to-device (D2D) integrated sensing and communications (ISAC) deployment in sixth generation (6G) networks. The antenna architecture comprises of three dielectric laminates arranged one below/above the other with each substrate juxtaposed to its counterpart by the air cavity. The upper laminate encompasses solitary element frequency selective surface (FSS) etched on both fronts. Impedance matching transmission lines and partly reactive impedance surfaces (RIS) were printed on the top and bottom region of the middle substrate, respectively. The lower laminate features microstrip feed lines on the top side and semi ground planes on the bottom. The MIMO antenna was made up of two ports and fed through proximity coupling from the opposite ends of the middle substrate’s top surface to resonate with a −10 dB impedance bandwidth (I-BW) of $\sim $ 35%. The partial RIS enabled $>$ 20 dB of isolation between the ports while the air cavities between the laminates contributed to achieve a realized gain of $>$ 7 dBi. The antenna occupies $1.2\lambda \times 1.2\lambda $ footprint and $0.1\lambda $ height at 12 GHz to exhibit quasi-OCP in the azimuth plane with axial ratio (AR) of < 3 dB and efficiency of $>$ 90%. The envelope correlation coefficient (ECC), diversity gain, specific absorption rate (SAR), and power density (PD) at the band of interest were < 0.1, $\sim $ 10 dB, < 1.6 W/kg, and < 10 W/ $\text{m}^{2}$ , respectively. The results of the Ansys HFSS simulations and the measurements taken within the anechoic chamber exhibited good agreement. In contrast to state-of-the-art quasi-OCP antennas operating in the 12 GHz spectrum, the novelty of the proposed MIMO antenna includes a straightforward and compact configuration that is integrated synergistically to provide reasonably high gain and efficiency values.

Morphological control of all‐polymer blends is quintessential yet challenging in fabricating high‐performance organic solar cells. Recently, solid additives (SAs) have been approved to be capable in tuning the morphology of polymer: small‐molecule blends improving the performance and stability of devices. Herein, three perhalogenated thiophenes, which are 3,4‐dibromo‐2,5‐diiodothiophene (SA‐T1), 2,5‐dibromo‐3,4‐diiodothiophene (SA‐T2), and 2,3‐dibromo‐4,5‐diiodothiophene (SA‐T3), were adopted as SAs to optimize the performance of all‐polymer organic solar cells (APSCs). For the blend of PM6 and PY‐IT, benefitting from the intermolecular interactions between perhalogenated thiophenes and polymers, the molecular packing properties could be finely regulated after introducing these SAs. In situ UV/Vis measurement revealed that these SAs could assist morphological character evolution in the all‐polymer blend, leading to their optimal morphologies. Compared to the as‐cast device of PM6 : PY‐IT, all SA‐treated binary devices displayed enhanced power conversion efficiencies of 17.4–18.3 % with obviously elevated short‐circuit current densities and fill factors. To our knowledge, the PCE of 18.3 % for SA‐T1‐treated binary ranks the highest among all binary APSCs to date. Meanwhile, the universality of SA‐T1 in other all‐polymer blends is demonstrated with unanimously improved device performance. This work provide a new pathway in realizing high‐performance APSCs. [ABSTRACT FROM AUTHOR]

Oxidation self-charging batteries have emerged with the demand for powering electronic devices around the clock. The low efficiency of self-charging has been the key challenge at present. Here, a more efficient autoxidation self-charging mechanism is realized by introducing hemoglobin (Hb) as a positive electrode additive in the polyaniline (PANI)-zinc battery system. The heme acts as a catalyst that reduces the energy barrier of the autoxidation reaction by regulating the charge and spin state of O2. To realize self-charging, the adsorbed O2 molecules capture electrons of the reduced (discharged state) PANI, leading to the desorption of zinc ions and the oxidation of PANI to complete self-charging. The battery can discharge for 12 min (0.5 C) after 50 self-charging/discharge cycles, while there is nearly no discharge capacity in the absence of Hb. This biology-inspired electronic regulation strategy may inspire new ideas to boost the performance of self-charging batteries. [ABSTRACT FROM AUTHOR]

A formaldehyde-free reactive flame retardant, an ammonium salt of triethylenetetramine phosphoryl dimethyl ester phosphamide phosphoric acid (ATPEPDPA), was synthesized and characterized using nuclear magnetic resonance (NMR). Fourier transform infrared spectroscopy test (FT-IR), durability test and scanning electron microscopy (SEM) results suggested that ATPEPDPA was successfully grafted on cotton fabrics through a -N-P(=O)-O-C covalent bond. Moreover, the limiting oxygen index (LOI) value of 20 wt% ATPEPDPA-treated cotton was 44.6%, which met stringent washing standard after 50 laundering cycles (LCs). The high washing resistance of the ATPEPDPA-treated cotton was due to the p-π conjugation between the N atom and the P(=O) group in the flame-retardant molecule, which strengthened the stability of the -N-P(=O)-O-C bonds between ATPEPDPA and cellulose, and the -N-P(=O)-(O-CH3)2 groups in the ATPEPDPA. The cone calorimetric test showed that the treated cotton had excellent flame retardance. In addition, the TG and TG-IR tests suggested that ATPEPDPA performed a condensed flame retardance mechanism. Furthermore, the physical properties and hand feel of the treated cotton were well maintained. These results suggested that introducing -N-P(=O)-(O-CH3)2 and -N-P(=O)-(ONH4)2 groups into ATPEPDPA could significantly increase the fire resistance and durability of cotton fabrics. [ABSTRACT FROM AUTHOR]

In this paper, a novel source second harmonic manipulation architecture achieving second harmonic control at device input is proposed to solve the issue of reduced operating efficiency of power amplifiers (PAs) caused by the input nonlinearity in continuous Class‐GF mode. The key to the proposed architecture lies in the use of a compact multibranch network to match the source second harmonics of the three design frequency points to the short‐circuit state, which can expand bandwidth while avoiding unexpected efficiency degradation. Considering the necessity of theoretical verification, a broadband continuous Class‐GF PA is designed, implemented, and assembled employing a commercially available 10‐W gallium nitride device. The measured results show that a fractional bandwidth of 100% across 1.1–3.3 GHz with a drain efficiency of 62.4%–72.5%, an output power of 40.1–42.2 dBm, and a gain of 10.1–12.2 dBm are achieved under saturated output power. [ABSTRACT FROM AUTHOR]

This paper aims to solve large-scale and complex isogeometric topology optimization problems that consume significant computational resources. A novel isogeometric topology optimization method with a hybrid parallel strategy of CPU/GPU is proposed, while the hybrid parallel strategies for stiffness matrix assembly, equation solving, sensitivity analysis, and design variable update are discussed in detail. To ensure the high efficiency of CPU/GPU computing, a workload balancing strategy is presented for optimally distributing the workload between CPU and GPU. To illustrate the advantages of the proposed method, three benchmark examples are tested to verify the hybrid parallel strategy in this paper. The results show that the efficiency of the hybrid method is faster than serial CPU and parallel GPU, while the speedups can be up to two orders of magnitude. [ABSTRACT FROM AUTHOR]

Extended hybrid continuous mode expands the design bandwidth of the power amplifier (PA) by sacrificing drain efficiency. To balance the performance of drain efficiency and bandwidth, this letter limits the range of relevant parameters of its impedance space through theoretical analysis. An improved high‐efficiency load impedance space is proposed. Through the improved high‐efficiency impedance space, a PA operating at 0.8–2.2 GHz is designed, with a drain efficiency of more than 55% and an output power of more than 38.2 dBm, which verifies the design goals of broadband and high efficiency. [ABSTRACT FROM AUTHOR]

In this letter, a low insertion loss power divider/combiner with a power capacity exceeding 100 kW is presented. The discussion focuses on the simultaneous achievement of high efficiency and high‐power capacity, based on the compensation analysis of discontinuous coaxial lines. An 8‐way power divider/combiner, operating within the frequency range of 7.73–9.33 GHz, has been designed, fabricated, and subjected to experimental testing. The experimental results demonstrate that within a relative bandwidth of 18.8%, the highest efficiency surpasses 98.49% and the power capacity exceeds 100 kW. Furthermore, the return loss of the multiport is better than 22.5 dB, the single port exhibits a return loss better than 20.7 dB, and the minimum isolation among the multiport is better than 27.5 dB. By comparison with other recently reported power dividers/combiners, the proposed power divider/combiner possesses both high‐power capacity and high efficiency simultaneously. [ABSTRACT FROM AUTHOR]

In this letter, a novel design method of split‐ring resonator (SRR) as the input matching network (IMN) of power amplifier (PA) is proposed. Compared with conventional microstrip lines, SRR is capable of providing necessary harmonic short‐circuit while achieving broadband impedance matching. Applying the even–odd‐mode theory, the impedance transformation characteristics of SRR are analyzed and show SRR can perform accurate impedance matching. To verify the proposed method, a PA is designed and implemented, the input impedance of 10‐W GaN transistor is well matched to the source impedance by the SRR IMN in the operation band of 1.0–3.0 GHz. The measurement results show that the maximum drain efficiency of PA can reach 79.5% with 41.8 dBm of average output power in the operation band. [ABSTRACT FROM AUTHOR]

In this paper, a compact internally matched architecture of continuous class‐B/J Doherty power amplifier is studied. The influence of symmetric generalized combiner and postmatching network with harmonic control on the bandwidth and efficiency of Doherty power amplifier (DPA) is analyzed in detail. Based on the parameters obtained from theoretical analysis, a design method of internally matched continuous mode DPA (CM‐DPA) is proposed, and a broadband DPA with a size of 22.8 mm × $\times $ 24.5 mm was developed for experimental verification. The test structure shows that the maximum output power at saturation can reach 46.2 dBm. The efficiency of 6 dB back‐off is 58%–63.4%, with good consistency. In the reliability experiment, transistor and matching circuit of the CM‐DPA have a temperature below 100°C at saturation. The output power and efficiency tested at different temperatures (25∘ $2{5}^{\circ }$C, −55∘ $-5{5}^{\circ }$C, and 85∘ $8{5}^{\circ }$C) show that the DPA has high reliability. [ABSTRACT FROM AUTHOR]

Summary: By multiplying with the continuous factor (CF), the conventional Class‐ F/F−1, Class‐J power amplifier (PA) can be expanded to their corresponding continuous modes, resulting in a great degree of freedom for broadband design. However, this method can hardly apply to other types of PAs. In view of this problem, the continuous mode is deeply analyzed from the perspective of equation solving for the first time, and a general theory for high‐efficiency broadband continuous PA design is proposed. In this theory, the continuous impedance space does not rely on a mapping relationship achieved by multiplying with the CF, but on a direct solution of the high‐efficiency equations to obtain the broadband design space. This approach is simpler and has the potential to provide greater design space. As a validation, this theory is used for the analysis of Class‐E PAs and a new continuous Class‐E (NC‐E) PA is presented. With knee‐point voltage and finite harmonics taken into account, this type of PA greatly expands the broadband design space of Class‐E PAs and also has the advantage of harmonic matching. The NC‐E PA is designed and manufactured using GaN HEMT CGH40010F, which achieves 40.6–41.6 dBm output power and 66.2%–74.2% drain efficiency (DE) in the frequency band of 2.5–3.8 GHz. [ABSTRACT FROM AUTHOR]

Harvesting triplet excitons of large π‐conjugate aromatic molecules via cocrystal engineering for attaining near‐infrared (NIR) phosphorescence has aroused wide attention due to its fundamental significance and practical application. Herein, the pyrene (Py)‐N, N'‐bis(1‐ethylpropyl)‐2,5,8,11‐tetrakis(p‐methyl‐phenyl)‐perylenediimide (MP) organic cocrystal is designed and fabricated via the solution self‐assembly method, which demonstrates the NIR phosphorescence with a maximum peak at 730 nm and a photoluminescence quantum yield of 34.2%. The singlet states with an intermediate energy level from MP molecules bridges singlet and triplet states of Py molecules, resulting in efficient NIR phosphorescence. Importantly, the loose packing pattern makes MP an excellent elementary molecule that can be assembled with a variety of aromatic molecules, from ternary to six‐membered benzene rings and even larger benzene skeletons. In contrast to the limitations of traditional cocrystal systems, cocrystal engineering based on MP molecules with weak π–π interactions is no longer limited to the careful selection and collocation of molecular structures, uncertain assembly behavior, and unpredictable properties. This work holds considerable insights for the exploration of novel NIR phosphorescent materials via a universal strategy. [ABSTRACT FROM AUTHOR]

Our community is still far away from achieving self‐sustainable ambient intelligence, since it calls for rational energy layouts to satisfy the ubiquitous power demands from diverse terminal products. Harnessing energy directly from the surroundings thus provides ideal solutions. The majority of existing environmental harvesters rely on sophisticated procedures and expensive or toxic materials; while others attempt to streamline the complexity at the cost of compromising performance. This entails transducers that exhibit superb outputs and also employ cost‐effective, even recycled materials and straightforward protocols to render ubiquitous deployments. Here, a high‐efficiency droplet energy nanogenerator (DENG) is devised to satisfy all the requirements. The DENG is fabricated by directly coating a composite layer on a recycled digital video disk surface. It achieves superb electricity generation from one droplet, with an output voltage of >190 V at an instantaneous power density of 65 W m−2, and an energy conversion efficiency of 3.60%. Diverse demonstrations confirm the applicability of the DENG in environmental networks, encompassing self‐sustainable "on plants" sensing systems, smart building windows, and remote environmental monitoring platforms. In light of these superiorities, it is believed that the DENG may open up new alternative routes for future energy strategies. [ABSTRACT FROM AUTHOR]

Tool path planning is critical to fully realise the producing capabilities of multi-axis machine tools and improve the precision and efficiency in multi-axis machining. Up to now, more than 400 articles have been published for tool path planning of multi-axis machine tools. Among them, most of the articles mainly focus on the topology of tool path while few studies are conducted for planning of tool orientation. Moreover, the factors that affect the planning of tool orientation are derived from multiple aspects, such as interference, collision and cutting strip width, which poses great challenges on tool orientation planning. To generate a time-optimal tool path with high machining precision, there is an urgent need to ascertain the influences of tool orientation arrangement on the multi-axis machining process. Therefore, in this work, a literature review on tool orientation planning of multi-axis machine tools is implemented. The main factors that influence the planning of tool orientations are systematically summarised, and the advantages and disadvantages of the corresponding methods related to these factors are discussed. Some research issues and challenges encountered in the tool orientation planning are identified. Furthermore, the methodologies that have potential to address the research issues in the future are prospected. [ABSTRACT FROM AUTHOR]

Abstract How to improve the capacity of light‐harvesting is still an important point and essential strategy for the assembling of high‐efficiency quantum dot–sensitized solar cells (QDSCs). A believable approach is to implant new light absorption materials into QDSCs to stimulate the charge transfer. Herein, the few‐layer black phosphorus quantum dots (BPQDs) are synthesized by electrochemical intercalation technology using bulk BP as source. Then the obtained BPQDs are deposited onto the surface of Zn–Cu–In–S–Se (ZCISSe) QD‐sensitized TiO2 substrate to serve as another light‐harvesting material for the first time. The experimental results have shown that BPQDs can not only increase the absorption intensity by photoanode but also reduce unnecessary charge recombination processes at the interface of photoanode/electrolyte. Through optimizing the size and deposition process of BPQDs, the champion power conversion efficiency of ZCISSe QDSCs is increased to 15.66% (26.88 mA/cm2, Voc = 0.816 V, fill factor [FF] = 0.714) when compared with the original value of 14.11% (Jsc = 25.41 mA/cm2, Voc = 0.779 V, FF = 0.713).

Pesticide residues in fruits and vegetables present a significant concern for human health and safety. By 2022, an average of 3 million people worldwide is poisoned by pesticides every year, and the mortality rate can reach about 20%. This comprehensive review summarizes recent research on the detection of pesticide residues, focusing on the main detection methods and their implications. The study highlights the growing importance of biosensors as a prominent technique, offering enhanced efficiency and accuracy in pesticide residue analysis. The review addresses the challenges associated with pretreatment methods and discusses the advantages and limitations of biosensors. Furthermore, it emphasizes the need for further research to optimize the adaptive capabilities of biosensors, particularly their anti-interference abilities. The findings underscore the significance of developing intelligent adaptive sensors for on-site pesticide residue detection, eliminating the need for complex sample pretreatment. This comprehensive review serves as a valuable reference, facilitating future advancements in pesticide residue analysis, ensuring food safety, and safeguarding consumer health in modern agriculture.

Summary: Continuous mode provides better bandwidth performance and constant efficiency by offering greater design flexibility in fundamental and harmonics. However, this mode is mainly applicable to limited classes of power amplifiers (PAs) (such as Class‐F, Class‐J, and their derived types). In view of this problem, this paper proposes a general design theory for high‐efficiency broadband continuous PAs, which can easily extend any waveform of PAs to obtain the continuous impedance space. In theoretical analysis, first, the high‐efficiency equations are analyzed from the perspective of frequency domain. Furthermore, combining time domain constraints, a general continuous mode analysis and solution theory is presented. The theory is applied to the bandwidth expansion of Class‐EF PAs, resulting in a new continuous Class‐EF (C‐EF) mode that maintains constant efficiency while offering greater broadband design freedom. The proposed theory is verified by fabricating a C‐EF PA using GaN HEMT CGH40010F, which demonstrated output power (Pout) ranging from 39.5 to 41.2 dBm and drain efficiency (DE) of 69.5% to 79.2% in the frequency range of 2.5–3.6 GHz. [ABSTRACT FROM AUTHOR]

Defects in perovskite films are still the dominant destroyer of both power conversion efficiency (PCE) and long‐term stability in perovskite solar cells (PSCs). As the most popular electron transport layer (ETL), TiO2 film is used in many PSCs to achieve high PCE. However, pristine TiO2 by itself is not sufficient as an ETL due to lattice mismatch, poor alignment of the energy level gap, and hysteresis of the PSC. Herein, ammonium sulfamate (AS), with desired NH4+ and S═O functional groups, is designed to modify the TiO2 surface and interface to improve the PCE of PSCs. It is found that the AS works like a seed layer for the perovskite deposition, and, in addition, it effectively forms a bridge between the TiO2 surface and the perovskite. As a result, PSCs are successfully fabricated with a champion power conversion efficiency of 24.78% with smaller hysteresis. The PSCs prepared using the AS‐modified TiO2 also show excellent stability, and the bare device without any encapsulation retains 96% of its initial PCE after 1056 h of ambient exposure at 25 °C and 25% relative humidity. [ABSTRACT FROM AUTHOR]

Perovskite photovoltaics (PVs) are an emerging solar energy generation technology that is nearing commercialization. Despite the unprecedented progress in increasing power conversion efficiency (PCE) for perovskite solar cells (PSCs), up‐scaling lab‐made cells to solar modules remains a challenge. In this work, the recent progress of making perovskite mini‐modules is reviewed. In particular, a database summarizing the module size, performance, hysteresis, and operational lifetimes reported in the literature is built. After analyzing the performance losses from scaling PSCs to mini‐modules based on the data collected from the literature, the current key to high‐performance perovskite mini‐modules is found to be the coating method optimization. If the perovskite layer quality is well reserved, a >24% mini‐module efficiency is projected by only considering the losses from lateral resistivity and laser scribing area. Next, performance characteristics are explored including hysteresis and meta‐stable power outputs that must be overcome to correctly characterize perovskite modules. Finally, current challenges associated with the long‐term stability of perovskite modules are examined and the importance of such durability for commercialization is discussed. It is hoped that the findings in this review provide a bridge for the development of perovskite modules that will lead to commercialization in the near future. [ABSTRACT FROM AUTHOR]

Organic light-emitting diodes (OLEDs) have outperformed conventional display technologies in smartphones, smartwatches, tablets, and televisions while gradually growing to cover a sizable fraction of the solid-state lighting industry. Blue emission is a crucial chromatic component for realizing high-quality red, green, blue, and yellow (RGBY) and RGB white display technologies and solid-state lighting sources. For consumer products with desirable lifetimes and efficiency, deep blue emissions with much higher power efficiency and operation time are necessary prerequisites. This article reviews over 700 papers covering various factors, namely, the crucial role of blue emission for full-color displays and solid-state lighting, the performance status of blue OLEDs, and the systematic development of fluorescent, phosphorescent, and thermally activated delayed fluorescence blue emitters. In addition, various challenges concerning deep blue efficiency, lifetime, and approaches to realizing deeper blue emission and higher efficacy for blue OLED devices are also described. [ABSTRACT FROM AUTHOR]