Search

In wireless communication and radar systems, long-distance signal transmission poses significant challenges that affect overall system performance. In this paper, we propose an innovative bistatic radar cross section (RCS) testing system designed to address these challenges, with a particular focus on its long-distance signal transmission capabilities. This system is capable of accurately measuring the RCS of a target and improving multipath channel modeling accuracy by using precise RCS values. The integrated upper computer software extracts amplitude and phase information from received echo signals, processes these data, and provides detailed outputs including the target's RCS, one-dimensional image, and two-dimensional image. The experimental results obtained prove that this system can not only achieve effective long-distance signal transmission but also substantially enhance the accuracy of RCS measurements, offering reliable support for multipath channel modeling. However, the conclusions drawn are preliminary and require further experimental validation to fully substantiate this system's performance. Future work will focus on improving system accuracy, minimizing the impact of environmental noise, and optimizing data-processing methods to enhance the efficiency of wireless communication and radar applications. [ABSTRACT FROM AUTHOR]

The combination of photovoltaic system and electrochemical technology can not only improve the treatment efficiency, reduce energy consumption and operating costs, but also help promote the application of clean energy in environmental protection and water resources management, and has a good application prospect for achieving sustainable and efficient sewage treatment. The application of photovoltaic conversion of solar energy in wastewater treatment is described, and the research progress of photovoltaic conversion in electrooxidation system, reverse osmosis process, electrocoagulation process, aeration equipment, electroflocculation technology and fenton technology is reviewed. The future research direction of solar energy application in wastewater treatment is also proposed [ABSTRACT FROM AUTHOR]

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

4,4-Difluoro-4-bora-3a,4a-diaza-sindacene (BODIPY) is a sort of photofunctional dye which possesses advantages including strong light-capturing property, high photon-resistance, etc. Meso-N substituted aza-BODIPY is a crucial derivative of BODIPY scaffold that has the favorable optical properties and a significant spectral redshift. The photophysical properties can be tuned by molecular design, and the attenuation path of the excited state energy release of absorbed light energy can be well controlled via structural modifications, enabling tailored application. It has been extensively employed in life medicine fields including fluorescence imaging diagnosis, photodynamic therapy photosensitizer and photothermal therapy reagent and so forth. Extensive research and review have been performed in these areas. However, BODIPYs/aza-BODIPYs have a significant role in energy, catalysis, optoelectronics, photo-responsive materials and other fields. Nevertheless, there are relatively few studies and reviews in these fields on the modification and application based on BODIPY/aza-BODIPY scaffold. Herein, in this review we summarized the application of BODIPY/aza-BODIPY in the aforementioned fields, with the molecular regulation of dye as the foundation and the utilization in the above fields as the objective, in the intention of providing inspiration for the exploration of innovative BODIPY/aza-BODIPY research in the field of light resource conversion and functional materials.

Image sensors on silicon have the problems of small size and high cost. Therefore, we propose a method for making image sensors on glass substrates and analyzes the feasibility of replacing Image Sensors on Silicon from the performance and cost. Through calculation and measurement, the scanning resolution, conversion gain, signal‐to‐noise ratio, and scanning time of image sensors on glass substrates can all meet the requirements of the document scanner and barcode scanner; In addition, the image sensors on glass can be formed in large size and does not require splicing, resulting in lower costs compared to image sensors on silicon of the document scanner. Therefore, image sensors on glass can replace image sensors on silicon of the document scanner. The cost and the module size of the barcode scanner is higher than the existing product, So image sensors on glass used for barcode scanners is lack of advantages in application. [ABSTRACT FROM AUTHOR]

In wireless communication and radar systems, long-distance signal transmission poses significant challenges that affect overall system performance. In this paper, we propose an innovative bistatic radar cross section (RCS) testing system designed to address these challenges, with a particular focus on its long-distance signal transmission capabilities. This system is capable of accurately measuring the RCS of a target and improving multipath channel modeling accuracy by using precise RCS values. The integrated upper computer software extracts amplitude and phase information from received echo signals, processes these data, and provides detailed outputs including the target’s RCS, one-dimensional image, and two-dimensional image. The experimental results obtained prove that this system can not only achieve effective long-distance signal transmission but also substantially enhance the accuracy of RCS measurements, offering reliable support for multipath channel modeling. However, the conclusions drawn are preliminary and require further experimental validation to fully substantiate this system’s performance. Future work will focus on improving system accuracy, minimizing the impact of environmental noise, and optimizing data-processing methods to enhance the efficiency of wireless communication and radar applications.

Graphene and related two-dimensional materials have attracted great research interests due to prominently optical and electrical properties and flexibility in integration with versatile photonic structures. Here, we report an in-fiber photoelectric device by wrapping a few-layer graphene and bonding a pair of electrodes onto a tilted fiber Bragg grating (TFBG) for photoelectric and electric-induced thermo-optic conversions. The transmitted spectrum from this device consists of a dense comb of narrowband resonances that provides an observable window to sense the photocurrent and the electrical injection in the graphene layer. The device has a wavelength-sensitive photoresponse with responsivity up to 11.4 A/W, allowing the spectrum analysis by real-time monitoring of photocurrent evolution. Based on the thermal-optic effect of electrical injection, the graphene layer is energized to produce a global red-shift of the transmission spectrum of the TFBG, with a high sensitivity approaching 2.167×104 nm/A2. The in-fiber photoelectric device, therefore as a powerful tool, could be widely available as off-the-shelf product for photodetection, spectrometer and current sensor.

The manufacturing of flutes has always relied on traditional ceramics and metals, which may be affected by various factors during the manufacturing process, as well as the lack of intelligent sensing functions, resulting in poor sound quality and performance of the instrument. The purpose of this article is to explore the use of the intelligent sensing function of conjugated materials to create intelligent flute training equipment, achieve automatic tuning, volume control, etc., and improve the playing experience and training effect of the instrument. This article first analyzes the smart sensing function of conjugate materials and applies it to smart flute training equipment; then, introduces photosensitive materials at appropriate locations to change the size and shape of the flute’s sound hole, thereby adjusting the timbre; finally, uses smart flute training based on conjugate materials for real-time perception of performers’ performance experiments. The test results show that the average delay time of the conjugate material trench is reduced by 73.1% compared with the average delay time of the ceramic trench, and is reduced by 63.5% compared with the average delay time of the metal trench. This shows that the conjugated material flute is more intelligent and can quickly respond to the player’s performance and automatically control and respond.

Molecular self–assembly is the automatic formation of functional assemblies of different structural components through weak, reversible, non–covalent interactions on the basis of molecular recognition. Amphiphilic molecules have a natural advantage in self–assembly at the gas/liquid interface. In this work, two amphiphilic molecules with a special molecular structure, indocyanine green (ICG) and a derivative of indocyanine green (CCS), were combined with two dye molecules (tetraphenylporphyrin tetrasulfonic acid hydrate (TPPS) and nickel (II) phthalocyanine–tetrasulfonic acid tetrasodium salt (TsNiPc) for self–assembly through the Langmuir–Blodgett (LB) technique. The nanostructure and assembly behavior in ordered self–assembled films are effectively regulated by inducing dye molecules to form different types of aggregates (H– and J–aggregates). In addition, we prepared composite films containing the same functional components using the conventional drop–casting technique and performed a series of comparative experiments with LB films. The degree of hydrophilicity was found to be related to roughness, with LB composite films being flatter and denser, with the lowest roughness and the best hydrophobicity compared to drop–casting films. Notably, the LB films showed better optoelectronic properties under the same conditions, providing new clues for the application of optoelectronic functional ultrathin film devices. [ABSTRACT FROM AUTHOR]

In order to address the issue of a solar utilization system with low efficiency, this paper designs a new solar conversion system based on photovoltaic concentration and spectral splitting. The system concentrates sunlight through a Fresnel lens and uses a hollow concave cavity to evenly distribute the incident energy flow. The spectral splitting medium separates the useful irradiance for the PV cell from those wavelengths that are more suited to heat generation. By considering the available wavelength of photovoltaic cells, the GaAs cell and a ZnO nanofluid were selected for this paper. It was found that installing the hollow concave cavity improved the spot uniformity of the PV cell surface by 17%. The output efficiency of the system under various circumstances was analyzed. The results show that at a concentration ratio of 50 and a light intensity of 1000 W/m2, photoelectric conversion efficiency increased by 0.81%. When compared to direct concentration, the photoelectric conversion efficiency increased by at least 7%. Meanwhile, the comprehensive electrical efficiency was 36.7%, which is higher than that of the normal concentration PV and comprehensive thermal system. [ABSTRACT FROM AUTHOR]

Abstract Parameter estimation for solar photovoltaic (PV) models is a challenging issue due to the complex nonlinear multivariable of the current‐voltage and power‐voltage characteristics. In this article, an improved heap‐based algorithm (IHBA) is proposed to improve the performance of a recently published algorithm called heap‐based algorithm (HBA). The HBA's performance is enhanced by applying an effective exploitation feature to boost the searching around the leader position with the goal of enhancing its global search capabilities and avoiding becoming trapped in a local optimum. The proposed IHBA and the standard HBA are developed considering the practical limits of the electrical parameters of PV models to minimize the root mean square error (RMSE) between the experimental and simulated results. The numerical analyses for the PVM‐752GaAs PV module including single‐diode model (SDM), double‐diode model (DDM) and triple‐diode model (TDM) are investigated to estimate five, seven, and nine electrical parameters of these models, respectively. Besides, different recent optimization techniques are simulated with fair comparisons, which are forensic‐based investigation (FBI), equilibrium optimizer (EO), Jellyfish Search (JFS), HBA, Marine Predator Algorithm (MPA) and Enhanced MPA (EMPA), and are compared with the proposed IHBA. Several separate runs are illustrated for the proposed IHBA in comparison with others, whereas the whisker box plot and T‐tests are activated to evaluate their effectiveness metrics. The simulation results derive higher superiority of the proposed IHBA with the minimum RMSE objective and standard deviation of (0.000228 and 3.7 × 106), (0.000184 and 1.93 × 105) and (0.000017 and 2.11 × 105) for SDM, DDM, and TDM, respectively, with respect to the standard HBA, other recent and reported optimization techniques. Additionally, the P‐indicator is applied in this study to illustrate the evidence for the alternative hypothesis. Small values of the P‐indicator for the proposed IHBA are obtained compared to the standard HBA and other recent optimization techniques, where IHBA achieves p‐value of 1.0336 × 1017, 4.037 7× 1011 and 2.1490 × 1010 for SDM, DDM and TDM, respectively. The H‐value is always one which elucidates that the hypothesis probability is not more than 5% for all algorithms for SDM, DDM and TDM. Moreover, the proposed IHBA demonstrates higher efficiency as it provides the first ranks in the confidence interval values compared with other algorithms. Furthermore, the proposed IHBA is significantly employed for the SQ_150 PV module considering the TDM with diverse solar irradiance and temperatures, where significant closeness between the emulated and experimental P–V curves is evidently demonstrated.

A tri-state optical signal detector (TOD) is designed in this article to improve the accuracy and stability of decoding results of the ternary optical computer (TOC). The TOD consists of three modules: a light-sensing module, a voltage divider module, and a data latching and conversion module. First, a voltage divider circuit with adjustable resistors is used to achieve parallel optical–electrical signal conversion for each LCD pixel on a photosensitive sensor plus a latch structure. Second, the problem of the parallel storage of data after photoelectric conversion is solved. Third, a transcoding circuit from the output signal of the TOD to the input signal of the tri-state optical encoder (TOE) is given. The experimental results show that the tri-state optical signal detector designed in this paper is effective and feasible. [ABSTRACT FROM AUTHOR]

The incorporation of high‐precision intelligent manufacturing technologies into patterned metal halide perovskite production has attracted scientific and commercial interest because of advantages in terms of designable and controllable processes, multiscale and multimaterial construction strategies, and improved energy‐conversion performance. Here, the current developments in intelligent manufacturing technologies are reviewed for patterned and tailored perovskite structures. Six high‐precision approaches, namely, nanoimprint lithography, space‐confined growth, ink‐based direct printing, laser‐induced nucleation, modification using a laser, and high‐energy etching, are investigated and summarized. The focus of the review is on the basic principles of intelligent manufacturing methods, process optimization, and controllable perovskite microstructures. Additionally, the performance improvements of patterned and tailored perovskites and their devices, including photodetectors, solar cells, lasers, information storage and encryption devices, anticounterfeiting devices, and full‐color display applications, are discussed. The potential future applications of shaped perovskites fabricated via intelligent manufacturing technologies are promising. [ABSTRACT FROM AUTHOR]

[Display omitted] • Three-dimensional Mo-WO 3 and N719/Al-TiO 2 were synthesized. • A multifunctional Mo-WO 3 @N719/Al-TiO 2 was constructed. • Under dual-control, Mo-WO 3 @N719/Al-TiO 2 shows the most excellent performance. Under optical and electrical control, a multifunctional electro-optical dual-control color-changing and energy-storage device not only realizes quick color conversion, but also achieves good storage performance. In this work, Mo doped WO 3 (Mo-WO 3) films were synthesized through one-step hydrothermal method and N719/Al doped TiO 2 (N719/Al-TiO 2) films were synthesized by hydrothermal and dip-dyeing method. Eventually, choosing Mo-WO 3 as cathode and N719/Al-TiO 2 film as anode, a multifunctional electro-optical dual-control Mo-WO 3 @N719/Al-TiO 2 color-changing and energy-storage device was constructed. Under electrical control, the device shows excellent coloration efficiency (73.99 cm2/C), fast color switching rate (coloring/ bleaching time is 3.6 s/1.4 s), obviously improved area capacitance (about 82.6 mF/cm2) and excellent cycle stability. Under optical control, the device also shows shortened response time (coloring/ bleaching is 64.3 s/143.4 s), outstanding coloration efficiency (70.49 cm2/C), better area capacitance (about 58.6 mF/cm2) and excellent photoelectric conversion efficiency (10.56 %). [ABSTRACT FROM AUTHOR]

The Langmuir-Blodgett (LB) technique can be used to obtain highly ordered arrangement and assembly of high polymer molecular chains, and the obtained LB films exhibit the controllable structures and special physicochemical properties. Here, we successfully prepared the composite LB films based on bisphenol fluorene (BPF) and epoxy bisphenol fluorene (DGPF) by LB technique, as well as explored the microstructures of the composite LB films by atomic force microscopy (AFM) and transmission electron microscopy (TEM). The different aggregation states of various dye molecules in the composite LB films are investigated by UV–vis. Interestingly, the composite LB film electrodes exhibit promising photoelectrochemical properties. In particular, BPF/MB and DGPF/MB LB films show better photoelectric conversion efficiency. It is attributed to the ordered arrangement of BPF and DGPF and their effective aggregation with dye molecules, which improves the light absorption ability and charge transfer efficiency of the materials. Therefore, the prepared LB films based on the synthetic polymers BPF and DGPF are expected to play an important role in microelectronics. [Display omitted] • Develop novel Bisphenol fluorene and Epoxy bisphenol fluorene-based composite Langmuir-Blodgett films. • Demonstrate the photoelectric conversion performance. • Composite LB films showed high photoelectric conversion efficiency. • Potential applications in microelectronics functional device. [ABSTRACT FROM AUTHOR]

An optoelectronic integrated chip combining vernier coding and Gray coding is designed in this study. The structure that combines two encoding methods provides a more accurate delineation of the angles. This improves the accuracy of angle measurement. In addition, the chip incorporates a specially shaped photodiode array. It is designed with a special boundary function to filter out odd harmonics. The chip also integrates a fully differential amplifier to reduce common mode noise and filter out even harmonics. Based on the 0.35 μm CMOS process, the chip area is 3.41 mm × 2.91 mm. The measurement shows that the chip can operate normally in the ambient temperature of −40 °C–125 °C. Moreover, the chip can output sinusoidal signals and Gray code signals with good orthogonality and accuracy when the motor speed is within 3000 rpm. [ABSTRACT FROM AUTHOR]

Semiconductive metal-organic frameworks (MOFs) with donor-acceptor (D-A) characteristics have garnered attractive attention due to their capacity for separating and transferring photogenerated charges, making them promising candidates for high-performance X-ray detectors. However, the low charge transfer efficiency between the metal nodes and organic ligands limits the X-ray-to-electricity conversion efficiency of these materials. Herein, an additional photoactive donor (D') is introduced by incorporating a heavy atom-containing polyoxometalate (POM) [α-SiW 12 O 40 ] 4- into a binary {[Ni·bcbp·(H 2 O) 2 ]·(H 2 O) 4 ·Cl} n (Ni-bcbp, bcbp: H 2 bcbp·2Cl = 1,1'-bis(4-carboxyphenyl)(4,4'-bipyridinium) dichloride) MOF, resulting in a semiconductive ternary D-D'-A framework {[Ni 2 (bcbp) 2 ·(H 2 O) 4 ·(DMA)]·(SiW 12 O 40 )} n (SiW@Ni-bcbp, DMA: dimethylacetamide). The obtained material features an unprecedented porous 8-connected bcu-net structure that accommodates nanoscale [α-SiW 12 O 40 ] 4- counterions, displaying uncommon optoelectronic responses. In contrast to binary Ni-bcbp, the SiW@Ni-bcbp framework exhibits distinctive photochromism and robust X-ray responsiveness, which can be attributed to the synergistic effects of the electron reservoir and multiple photoinduced electron transfer originating from the POMs. As a result, the X-ray detector based on SiW@Ni-bcbp demonstrates a sensitivity of 5741.6 µC Gy air -1 cm -2 with a low detection limit of 0.49 µGy air s -1 . Moreover, the devices demonstrated the capability of producing clearness X-ray images, providing a feasible and stable solution for constructing high-performance direct X-ray detectors., (© 2024 Wiley‐VCH GmbH.)

Abstract This paper presents a new hybrid successive discretisation algorithm, used to calculate the parameters of the photovoltaic cells and panels, by the one diode model and the two diode model. Nine known datasets from the specialised literature were used to validate the new algorithm and then it was firstly applied for two new datasets. For the first time only one algorithm is applied to extract the parameters, in both cases—one and two diode models. The new datasets are for commercial monocrystalline silicon and amorphous silicon photovoltaic cells. The main test used to prove the performance of HDSA is the root mean square error. Other four tests were used for comparison: the mean absolute error, the mean bias error, t‐statistic, and the coefficient of determination. The hybrid successive discretisation algorithm proved its accuracy and reliability for parameter extraction of different types of photovoltaic cells and panels for all datasets used. Comparing the hybrid successive discretisation algorithm with the best algorithms from the specialised literature shows an improvement of the root mean square error by up to10.4% for the one diode model and by up to 7.5% for the two diode model, respectively.

Abstract The present study introduces an analytical approach for predicting net power for high‐concentrating photovoltaic systems (HCPV). Wind speed, surface radiation, and size of the backplate, which acts as a heat spreader, were found to be of high impact in increasing solar cell efficiency and maximum produced power. The efficiency increased by 5% as the wind shifted from light air (0.5 m/s) to fresh breeze (10 m/s). Also, it increased by 1.64% as the aluminium backplate shifted from a shiny (ɛ = 0) to a dark (ɛ = 1) surface. Furthermore, increasing heat‐spreader length or wind velocity caused a logarithmic increase in solar cell efficiency. On the other hand, both parameters caused an exponential increase in consumed power due to the operation of a tracking system. Thus, optimal values of heat‐spreader length at which maximum net power is produced exist. A case study based on the annual average values of the hourly‐basis meteorological data for the period 2015 to 2018 for two cities in Saudi Arabia was conducted. It was found that the size of the heat spreader could be reduced by 36% for concentration ratio up to 2000 while concurrently increasing the net power by 2.6% and 6% for the systems built in Riyadh and Dammam, respectively.

Highly‐polarizable materials are favorable for photoelectric conversion due to their efficient charge separation, while precise design of them is still a big challenge. Herein a novel polar oxyselenide, Sr6Cd2Sb6O7Se10, is rationally designed. It contains lateral sublattices of polarizable [Sb2OSe4]4− chains and highly‐orientated [CdSe3]4− chains. The intense polarization was evaluated by significant second‐harmonic generation (SHG) signal (maximum: 12.6×AgGaS2) in broad spectrum range. The polarization was found to mainly improve the carrier separation with a much longer recombination lifetime (76.5 μs) than that of the nonpolar compound Sr2Sb2O2Se3 (18.0 μs), resulting in better photoelectric performance. The single‐crystal photoelectric device exhibited excellent response covering broad spectrum in 500–1000 nm with stable reproducibility. This work provides some new insights into the structure design of highly‐polarizable heteroanionic materials for photoelectric conversion. [ABSTRACT FROM AUTHOR]

Abstract The photovoltaic (PV) cells are highly sensitive to temperature variations. The linear variation of PV cells with operating temperature could lead to the loss of conversion efficiency and permanent damage of PV material. To address this critical issue, while improving the performance of solar photovoltaic system (SPVS) during the operating period, the deployment of a proper cooling system is a prime requisite in the design process. Considering this, two new and cost‐effective cooling techniques are proposed in this study, which can improve efficiency and increase the life of the PV panel. The first technique is the active cooling design with water. The proposed design enhances the access to PV cells to maximize cooling. The second one is an improved passive cooling technique that uses fins mounted on the backside of PV module. This further reduces the temperature by increasing the heat dissipation. Additionally, a third PV module without any cooling system is deployed as a reference margin. The techniques have been experimentally evaluated and a recommendation is made in order to reduce the temperature variation across the PV panel.

Abstract The increased energy demand with recent advancement in technology has led the global energy producers to move towards solar energy. Partial shading is a phenomenon that can severely affect the production of the solar power in the photovoltaic system. With partial shading situation, the cascaded solar panels show numerous dummy peaks both in power–voltage (P–V) and current–voltage (I–V) curves, resulting in difficulty of extracting maximum power. A dummy peak elimination based MPPT technique is introduced in proposed work for accurate tracking of maximum power. The proposed dummy peak elimination based MPPT estimates the dummy peaks without imposing any high computational burden for the processor. The proposed technique has better dynamic response and is more compatible for real time application compared to existing optimization‐based techniques. The proposed dummy peak elimination based MPPT is tested on a practical system with 3S configuration having three 249 W PV panels for different shading patterns, which displays acceptable outputs with good dynamic performance and better efficiency.

Abstract As a clean and renewable energy source, solar energy is a competitive alternative to replace conventional fossil fuels. Nevertheless, its serious fluctuating nature usually leads to a poor alignment with the actual energy demand. To solve this problem, the direct solar‐to‐electrochemical energy conversion and storage have been regarded as a feasible strategy. In this context, the development of high‐performance integrated devices based on solar energy conversion parts (i.e., solar cells or photoelectrodes) and electrochemical energy storage units (i.e., rechargeable batteries or supercapacitors [SCs]) has become increasingly necessary and urgent, in which carbon and carbon‐based functional materials play a fundamental role in determining their energy conversion/storage performances. Herein, we summarize the latest progress on these integrated devices for solar electricity energy conversion and storage, with special emphasis on the critical role of carbon‐based functional materials. First, principles of integrated devices are introduced, especially roles of carbon‐based materials in these hybrid energy devices. Then, two major types of important integrated devices, including photovoltaic and photoelectrochemical‐rechargeable batteries or SCs, are discussed in detail. Finally, key challenges and opportunities in the future development are also discussed. By this review, we hope to pave an avenue toward the development of stable and efficient devices for solar energy conversion and storage.

Abstract Solar panels around the globe are primarily designed as a plug‐and‐play solution and the end users are not allowed to repair the panel in case of damage. Natural loadings such wind, snow, sand and hail can lead to irreparable damage to the solar panels and the easiest solution to fix the damaged solar panel is to replace it. This design philosophy leads to a huge quantity of electronic waste as it completely ignores the repairability of the solar panels. In this regard, the presented research work details the development and testing of modular solar panel with performance similar to the traditional design. The modular design was tested for power transfer, re‐connection upon impact and the ability to replace the selected parts in case of permanent damage without the need of replacing the entire solar panel. This experimental research work delivers a modular solar panel design that has ease of repairability in case of damage. Furthermore, a detailed economic analysis has been provided for several real‐world scenarios that indicate its suitability over existing commercially available solutions.

Abstract The maximum power generation in the solar photovoltaic (PV) array is reduced due to the abnormal conditions such as module mismatch, string faults and damage of the PV modules, which reduces the efficiency and reliability of the system. Conventional protection devices fail to detect the faults, which leads to protection issues and fire threats in the PV plants. This paper proposes a new fault detection algorithm to identify the faults in the PV array and the PV string. A simple analysis is developed for fault detection under different fault conditions, such as line–line (L‐L) fault, line–ground (L‐G) fault and short‐circuit fault with multiple strings, and the values of their current indicator and threshold are predetermined. Based on these values, the proposed fault detection algorithm identifies the fault in the PV array and the PV string, with a reduced number of current sensing devices. The effectiveness of the proposed algorithm is tested and verified through MATLAB simulation and experimentation under various operating conditions of the solar PV plant.

Abstract Photovoltaic emulators are a specific type of power electronics system to mimic the behaviour of a photovoltaic (PV) panel or array and facilitate the testing of energy systems. Existing solutions usually require sophisticated hardware design and fast computing. This paper presents a simple, reliable, and effective circuit‐based photovoltaic (PV) emulator based on the equivalent PV stacked cells. The PV emulator can be used for solar system testing and analysis, such as maximum power point tracking (MPPT) and partial shading effect. The I–V and P–V characteristic curves of the emulator have been generated by using an LTspice simulator. It is experimentally investigated and compared with a real PV panel and existing emulator products. The experiment results show good agreement with the mimicked actual PV panel. The proposed PV emulator shows a better dynamic response and shorter settling time than several benchmarked commercial products. The enhancement in the time response is due to the simplicity of the emulator, where a few power diodes and some resisters are used. In addition to simplicity, the PV emulator is very cost‐effective.

Abstract In this work, a new method for obtaining the current–voltage curve for crystalline silicon and thin‐film flat panels is presented. It is based on the single‐diode model, with a variable shunt resistance and series resistance. New expressions for the shunt resistance and open circuit voltage as a function of the temperature and irradiance are deduced. Besides, a procedure to translate the series resistance to arbitrary conditions is proposed. The diode ideality factor and shunt resistance are obtained by optimization. The rest of the parameters that appear in the current–voltage curve are obtained from the module measurements by means of theoretical expressions. The procedure for obtaining the current–voltage curve under arbitrary operating conditions is also described. The results obtained with the developed model are compared with experimental measurements in cadmium telluride and amorphous silicon modules, and with results published in the literature for other technologies. The model faithfully reproduces the experimental values. For all the modules, the root mean square error for the maximum power is lower than 2% (below 1.5% in most cases). These errors are lower than those reported in the literature for other models. In particular, the results are significantly more exact in the case of thin‐film modules.

Organic-inorganic hybrid perovskite solar cells have attracted much attention due to their excellent optoelectronic properties and low preparation cost. However, a large number of defects exist on the surface and grain boundaries of perovskite films, which lead to non-radiative recombination of carriers and affect the photoelectric conversion efficiency of solar cells. In this work, acetylsalicylic acid (ASA) was introduced into the lead salt solution as a passivator to prepare perovskite films and solar cells via a two-step method. The impacts of acetylsalicylic acid on film quality and cell performance were investigated by means of optical spectroscopy, scanning electron microscopy and various electrical measurements. The results show that the introduction of appropriate amount of ASA can obviously increase the grain size of perovskite films and effectively reduce the defect density of perovskite films via Lewis acid-base interaction. The solar cell prepared with the incorporation of 2.5 mmol/L ASA achieves the highest photoelectric conversion efficiency of 19.83%, appreciably outperforming the control device (17.47%). This work highlights the efficacy of ASA in passivating defects of perovskite films and provides a facile method to improve the performance of perovskite solar cells. [ABSTRACT FROM AUTHOR]

Bioelectronics, an emerging discipline formed by the biology and electronic information disciplines, has maintained a state of rapid development since its birth. Amongst the various functional bioelectronics materials, bacteriorhodopsin (bR), with its directional proton pump function and favorable structural stability properties, has drawn wide attention. The main contents of the paper are as follows: Inspired by the capacitive properties of natural protoplast cell membranes, a new bio-capacitor based on bR and artificial nanochannels was constructed. As a point of innovation, microfluidic chips were integrated into our device as an ion transport channel, which made the bio-capacitor more stable. Meanwhile, a single nanopore structure was integrated to improve the accuracy of the device structure. Experiments observed that the size of the nanopore affected the ion transmission rate. Consequently, by making the single nanopore's size change, the photocurrent duration time (PDT) of bR was effectively regulated. By using this specific phenomenon, the original transient photocurrent was successfully transformed into a square-like wave. [ABSTRACT FROM AUTHOR]

Abstract An effective and efficient photovoltaic performance is significantly affected by the interface between different constituents of dye sensitized solar cells (DSSC). A novel dual post treatment of TiCl4 and urea solutions on different layers of TiO2 electrode is addressed and the TiO2 particle morphology, dye‐adsorption amount on the TiO2 electrode and the photovoltaic performance of the DSSC based on those electrodes are characterised in this work. TiCl4 treatment can form more binding site on TiO2 particles and urea treatment structures a thin layer of g‐C3N4 on the surface of TiO2 particles. This strategy can not only effectively increase the dye‐adsorption for light‐harvesting, but also facilitate the electron transfer through inhibiting the charge recombination between TiO2 and electrolyte, and moreover, it provides excess electrons for the photoanodes. The DSSC fabricated from TiO2 electrode processed with urea treatment on the sixth layer exhibited the highest power conversion efficiency of 8.94% with a short current density Jsc of 24.09 mA cm–2, an open circuit voltage Voc of 583 mV and a fill factor of 63.8.

Abstract Optical wireless power transmission (OWPT) systems are attractive photonic systems based on light sources and solar cells. To improve the visual design of practical consumer applications, we applied visible colour filters to change the normal black appearance of solar cells. Different colours made by multilayer‐type filters on solar cells were investigated for control of visible colour with maintained power transmission efficiency. The surface colours seen by the eyes and standard cameras were controlled by the filter as expected from the filter spectral response. The electrical output characteristics of the solar cell covered with the filter were experimentally measured in order to confirm the OWPT performance. The results showed that the OWPT system can change colour appearance with an acceptable slight deterioration of performance.

Abstract This work aims at developing and validating mathematical models and empirically evaluating a water‐film cooling system for commercial photovoltaic modules. Methodologically, thermal, electrical and climatological data measured in a specific purpose on‐grid outdoor test unit were used. In this work they are used to study the improvement in the performance of photovoltaic energy production due to temperature reduction. The first‐order state‐space linear parametric model presents the best performance to predict the temperature of the uncooled photovoltaic modules, with normalised mean square error (NRMSE) of 86.75%. In contrast, the non‐linear model performance of cooled photovoltaic modules is lower, with NRMSE of 44.5%; however, the results show that the performance of the complete thermoelectric model is satisfactory, with NRMSE of 76.38%. On the other hand, empirical tests showed that the cooling system reduces temperature in 15–19%, on average, and to a maximum of 35%. In terms of power, there are average gains of 5–9%, and maximum gains of 12%. Regarding gross generation, there are average gains of 2.3–6%, and maximum gains of 12%. It was concluded that it is possible to mathematically model and predict this generation using non‐linear models with a 0.2% error between modelled and measured generation.

The photochargeable materials have drawn growing research interest for the application of direct photoelectric storage of solar energy. Carbon‐rich conjugated carbon nitride polymers with hybrid π‐conjugated structure combining heptazine motifs with graphitic carbon rings have drawn a lot of attention for the extended conjugation length, tunable band gap, and 2D thin‐layer structure. The carbon‐rich polymeric carbon nitride (CPCN) with a band gap of 1.74 eV is successfully applied in direct photoelectric storage of solar energy. However, the ambiguous underlying mechanism limits the performance improvement. Herein, the relationship of microstructure and photoelectrochemical properties of the CPCN material is further investigated using the techniques including nuclear magnetic resonance spectroscopy, transmission electron microscopy, X‐ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy, and cyclic voltammetry. The influence of the ratio of conjugated CNC to CCC on the band edge positions of the CPCN material, which directly relates to electron transport paths of the photo‐charging and discharging processes, is revealed. With the diffusion‐controlled charge storage regime, the CPCN cell obtains a specific capacity of 44.6 C g–1. [ABSTRACT FROM AUTHOR]

Photoelectric conversion (PC) is an essential process for the devices based on the utilization of electrical signals, such as solar cells, sensors, imaging, and communication. As an emerging research field, great advances are made in the PC devices based on the metamaterials (MMs) hitherto. The MMs exhibit unique electromagnetic resonance properties, which can be used for perfect absorbers and are promising for efficient PC from microwave to optical range, though the absorption mechanism varies with the waveband. Perfect absorption in the microwave is mainly induced by the electromagnetic polariton resonance, and surface plasmon resonance (SPR) becomes dominant as the frequency approaches to optical band. Thus, the MMs‐based photoelectric devices are realized via an electronic approach in the microwave band, and are based on the SPR‐induced hot carriers in the optical band. Since terahertz wave falls between the microwave and optical band, terahertz photoelectric devices exhibit unique characteristic different from the electronics and optics, while still bear similarity to both of them, which is dependent on the frequency. Hence, this review covers major advances in the aspects of fundamentals and engineering for the MMs‐based photoelectric devices from microwave to optical range. [ABSTRACT FROM AUTHOR]

The conventional thermal diffusion process for preparing P-N junction emitter of solar cells mainly consists of two steps: pre-deposition and high temperature drive-in. In this paper, high sheet resistance (Rs) emitters with a low surface phosphorus doping concentration were prepared on p-type multicrystalline silicon wafers by introducing a constant temperature process after the high temperature drive-in step. The influence of constant temperature on the Rs and phosphorus atom doping profile of P-N junction emitter was investigated. The results show that the Rs of the P-N junction with a certain constant temperature treatment can increase reversely. Correspondingly, the doping profiles tested by secondary ion mass spectrometry (SIMS) indicate that the phosphorus doping concentration at the surface of silicon was reduced when the constant thermal treatment at temperatures of 650 °C to 750 °C was carried out after the high temperature drive-in step. Compared with the conventional diffusion process, the Rs of the P-N junction with a constant temperature treatment at 700 °C for 15 min increased by about 3. 2 Ω/□, and the conversion efficiency Eff of the corresponding solar cells increases to 18. 69%, which is higher by 0. 23% than that of the Baseline. [ABSTRACT FROM AUTHOR]

Dielectric metamaterials with high refractive indices may have an incredible capability to manipulate the phase, amplitude, and polarization of the incident light. Combining the high refractive index and the excellent electrical characteristics of the hybrid organic-inorganic perovskites (HOIPs), for the first time we experimentally demonstrate that metamaterial made of HOIPs can trap visible light and realize effective photon-to-electron conversion. The HOIP metamaterials are fabricated by focused ion beam milling on a solution-grown single-crystalline HOIP film. The optical absorption is significantly enhanced at the visible regime compared to that of the flat HOIP film, which originates from the excited Mie resonances and transverse cavity modes with inhibited interface reflection. Furthermore, compared to the flat film, the HOIP metamaterial shows increased photocurrent of up to ~40%, where the effective photocarrier generation efficiency increases by ~40% and the related internal efficiency by ~20%. Our data point to the potential application of HOIP metamaterials for high-efficiency light trapping and photon-to-electron conversion.

According to the solar-blind characteristic of the pantograph arc spectrum distribution, an arc detection method based on the photoelectric conversion mechanism for urban rail was proposed, and the design of each part of the arcing detection system was completed. Through the analysis of arc spectral distribution, the 275-285 nm band was determined as the detection characteristic waveband. The optical acquisition system located on the roof of the train collects the arc characteristic light and transmits it to the photoelectric conversion module, which converts the received optical signal into the corresponding current signal linearly. After amplification, comparison and screening in this module, the optical signal is sent to the data processing module for output display. Finally, a field test conducted on an urban rail transit line shows that this arc detection system can effectively detect the pantograph arc phenomenon and reflect the arc intensity linearly avoiding the influence from natural light, train load and train running direction.

A tri-state optical signal detector (TOD) is designed in this article to improve the accuracy and stability of decoding results of the ternary optical computer (TOC). The TOD consists of three modules: a light-sensing module, a voltage divider module, and a data latching and conversion module. First, a voltage divider circuit with adjustable resistors is used to achieve parallel optical–electrical signal conversion for each LCD pixel on a photosensitive sensor plus a latch structure. Second, the problem of the parallel storage of data after photoelectric conversion is solved. Third, a transcoding circuit from the output signal of the TOD to the input signal of the tri-state optical encoder (TOE) is given. The experimental results show that the tri-state optical signal detector designed in this paper is effective and feasible.

Covalent carbon nitrides (CNs) have been widely used in photocatalysis and energy storage for their graphitic 2D structure and semiconducting properties. However, carbon nitrides, normally with a bandgap of 2.7 eV, can absorb only the ultraviolet and blue fraction of solar spectrum (λ

The immobilization of natural photosystem II (PSII) enzyme onto an artificial electrode offers an ingenious and promising avenue for semiartificial solar energy conversion. However, this process is significantly limited by the poor stability and the short life of PSII. Here, a new prototype of a semiartificial system is reported by anchoring PSII on polyethylenimine‐coated macroporous carbon electrode with a high load. Good electronic communication is established at the biointerface of this PSII electrode, enabling excellent photoelectrochemical (PEC) water oxidation and lasting electricity generation. The maximum turnover number of 10 200 ± 1380 mol O2 per mol PSII dimer is obtained in this system at around 10 h before complete deactivation, reaching high current‐to‐O2 conversion efficiencies. The functions of PSII to release O2 both in light and dark conditions as well as for H2O2 formation are revealed. Under periodic irradiation (AM 1.5G 1 sun), this PSII electrode allows for stable mediated photocurrent output of ≈4.31 µA cm−2 after five days, which represents the most stable photoelectric performance achieved so far for PSII‐related electrodes. [ABSTRACT FROM AUTHOR]

Strong ambient light and the resultant photoelectric conversion saturation of an avalanche photo diode (APD) may signficantly deteriorate the received signal in visible light communication (VLC) systems. Hence, in this paper we characterize the signal received from an APD under strong ambient light based on our experimental data. To illustrate the phenomenon of APD saturation, we investigate the transmission rate and analyze the link budget. In order to achieve dimming control, we then conceive a unary-coded VLC system for maintaining the user-defined dimming level. We calculate both the upper and lower bounds of the achievable transmission rate of the unary-coded VLC system.

As a clean and renewable energy source, solar energy is a competitive alternative to replace conventional fossil fuels. Nevertheless, its serious fluctuating nature usually leads to a poor alignment with the actual energy demand. To solve this problem, the direct solar‐to‐electrochemical energy conversion and storage have been regarded as a feasible strategy. In this context, the development of high‐performance integrated devices based on solar energy conversion parts (i.e., solar cells or photoelectrodes) and electrochemical energy storage units (i.e., rechargeable batteries or supercapacitors [SCs]) has become increasingly necessary and urgent, in which carbon and carbon‐based functional materials play a fundamental role in determining their energy conversion/storage performances. Herein, we summarize the latest progress on these integrated devices for solar electricity energy conversion and storage, with special emphasis on the critical role of carbon‐based functional materials. First, principles of integrated devices are introduced, especially roles of carbon‐based materials in these hybrid energy devices. Then, two major types of important integrated devices, including photovoltaic and photoelectrochemical‐rechargeable batteries or SCs, are discussed in detail. Finally, key challenges and opportunities in the future development are also discussed. By this review, we hope to pave an avenue toward the development of stable and efficient devices for solar energy conversion and storage. [ABSTRACT FROM AUTHOR]

We report the synthesis of a novel metal–organic capsule constructed from six pyrogallol[4]arene macrocycles, which are switched together by 16 FeIII and 16 CoII ions. This supramolecular structure is the first instance of a spheroidal heterometallic nanocage assembled through a one‐step metal–ligand coordination approach. This new assembly also demonstrates an important proof of concept through the formation of multiple heterometallic metal–metal interactions within the capsule framework. Photophysical and electrochemical studies of self‐assembled capsule films indicate their potential as semiconductors. These materials display unexpected photoelectric conversion properties, thus representing an emergent phenomenon in discrete metal–organic supramolecular assemblies. [ABSTRACT FROM AUTHOR]