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[IEEE 2019 Compound Semiconductor Week (CSW) - Nara, Japan (2019.5.19-2019.5.23)] 2019 Compound Semiconductor Week (CSW) - Organic Light-Emitting Diode Composed of an Oligomer Crystal Emission Layer
摘要： This paper considers a full-duplex (FD) point-to-point system consisting of one multi-antenna FD access point (FD-AP) and one two-antenna FD mobile station (FD-MS). We adopt simultaneous wireless information and power transfer scheme and apply the self-energy recycling at FD-MS. In order to minimize the weighted sum transmit power, we jointly design the transmit beamforming vector of FD-AP, the receive power splitting ratio of FD-MS, and the transmit power value of FD-MS. Since the original problem is non-convex, we apply semidefinite relaxation and obtain a new convex problem. We further prove that both problems have exactly the same solutions. Finally, simulations are provided to verify our analysis, and the comparison with a half-duplex system demonstrates the significant performance gain from self-energy recycling.
关键词： Full-duplex,SDR,optimality,self-energy recycling,SWIPT
更新于2025-09-19 17:13:59
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Waste to wealth translation of e-waste to plasmonic nanostructures for surface-enhanced Raman scattering
摘要： Here we report, for the first time, a simple one-step recycling of discharged batteries, a major constituent of electronic waste (e-waste), into value-added fluorescent nanomaterials-carbon quantum dots (CQDs). The e-waste derived CQDs (eW-CQDs) were systematically characterized for their optical properties, including absorption, photoluminescence, quantum yield, and emission lifetime. The morphology of these nanomaterials was determined by high-resolution transmission electron microscopy, selected area electron diffraction, and X-ray diffraction, whereas Raman spectroscopy was used to confirm their carbonaceous architecture. To broaden the range of applications, the eW-CQDs were employed in the synthesis of plasmonic nanostructures (eW-Au@CQDs) via a one-step chemical reduction strategy. Both eW-CQDs and eW-Au@CQDs were further tested for their suitability to be used as surface-enhanced Raman (SERS) substrates for the detection of methylene blue (MB), a model dye and Raman reporter. Our results show that while eW-CQDs are not ideal for SERS applications, eW-Au@CQDs, when deposited on a gold-modified screen-printed carbon electrode (SPE), produce strong MB SERS signals. With further optimization, these eW-Au@CQDs-modified SPEs could find applications in SERS-based sensing. This study demonstrates a new, promising, and sustainable approach of converting e-waste such as discharged batteries into value-added products with potential for a wide range of applications.
关键词： E-waste,Discharged batteries,Recycling,SERS,Carbon quantum dots,Methylene blue
更新于2025-09-19 17:13:59
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Device physics of back-contact perovskite solar cells
摘要： Back-contact perovskite solar cells (PSCs) are a promising candidate to further increase power conversion efficiency (PCE) and have been the subject of many investigations. However their full potential has not been achieved due a lack of a complete understanding of their operation from a device physics perspective. In this study, a detailed photoelectrical model for back-contact PSCs is developed by coupling a drift-diffusion description of free charge transport model with ion migration currents and emitted-carrier generation resulting from photon recycling. By studying the influence of relevant electrical parameters, the interplay between charge generation, transport and recombination, is revealed to further clarify the design principles based on devices with a back-contact structure. Although devices featuring the back-contact structure exhibit a sensitivity to electrical parameters, a high PCE exceeding 25% is predicted if the interface passivation and perovskite film quality can be well controlled. Different conduction band and valence band offsets offer various screening opportunities for functional materials with high efficiencies are introduced. Additionally, the simulated results revealed that mobile ions degrade the device performance if the average ion concentration exceeds 1016 cm?3. Furthermore, we point out that photon recycling can effectively compensate against radiative recombination, thereby resulting in an improved open circuit voltages. The results provide a new understanding of the carrier transport dynamics, ion migration, and photon recycling effects for the back-contact structure, which can be applied to a systematic improvement in the design of high efficiency PSCs.
关键词： Power conversion efficiency,Ion migration,Back-contact perovskite solar cells,Photoelectrical model,Photon recycling
更新于2025-09-19 17:13:59
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Potential environmental risk of solar cells: Current knowledge and future challenges
摘要： Photovoltaic (PV) technology such as solar cells and devices convert solar energy directly into electricity. Compared to fossil fuels, solar energy is considered a key form of renewable energy in terms of reducing energy-related greenhouse gas emissions and mitigating climate change. To date, the development and improvement of PV technologies has received substantial attention; however, their potential environmental risks remain unknown. Therefore, this review focuses on the potential risks of leachates derived from solar cell devices. We collect scientific literature on toxicity and leaching potential, tabulate the existing data, and discuss related challenges. Insufficient toxicity and environmental risk information currently exists. However, it is known that lead (PbI2), tin (SnI2), cadmium, silicon, and copper, which are major ingredients in solar cells, are harmful to the ecosystem and human health if discharged from broken products in landfills or after environmental disasters. Several research directions and policy initiatives for minimizing the environmental risks of PV technology are suggested. This review contributes to both solar energy and environmental science research.
关键词： Solar cell,Photovoltaic,Recycling,Toxicity,Leaching
更新于2025-09-19 17:13:59
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Environmental Criteria for Assessing the Competitiveness of Public Tenders with the Replacement of Large-Scale LEDs in the Outdoor Lighting of Cities as a Key Element for Sustainable Development: Case Study Applied with PROMETHEE Methodology
摘要： The technological change to LEDs is an unstoppable reality which, little by little, is becoming increasingly important in terms of the lighting inside and outside our homes. The exterior lighting of our cities is moving decisively and clearly towards the incorporation of this technology in urban spaces. The energy efficiency, light quality, and economic benefits of LED technology are an unquestionable reality. This is causing public administration projects involving large-scale switches to LEDs to be promoted and financed; however, it is beginning to be observed that the commitment to the policies decided by this technology should take into account some environmental aspects which have not been studied to date. The environmental impact of the substitutions is caused by the need to valorize the replaced luminaires. Until now, most have been stored without the possibility of use, reuse, or recovery. The environmental impact produced in the manufacture of LED luminaires that replace the old sodium vapor (VSAP) or metal halide (MH) discharge lamps must also be considered. In addition, in the administrative clauses specifications that govern the public tenders, it is observed that the fundamental environmental aspects both of recycling the old lamps, and of the life cycle analysis (LCA) of the luminaires that are replacing them, have not been contemplated or valued with sufficient weight. In addition, there are very few public substitution contests in which environmental criteria are rewarded or valued in an important way. This work intends to summarize a methodological proposal using the techniques of multiple decision-making criteria for the selection of bidding companies for public outdoor lighting competitions. We propose the use of the PROMETHEE method multi-criteria analysis for the application of the most commonly used criteria for the luminaire LED selection process, including an environmental impact assessment with LCA techniques, and propose this as a case or model guide in the public contests of cities. A model of the bidding conditions that addresses and assesses the environmental aspects which are absolutely key to sustainable development is supported by the ecological criteria of the circular economy.
关键词： environmental criteria,circular economy,Life cycle assessment LCA,lighting pollution,lighting public tender,PROMETHEE,recycling waste,LED luminaires,decision tool,streetlight waste
更新于2025-09-16 10:30:52
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Ultrasensitive and label-free detection of ATP by using gold nanorods coupled with enzyme assisted target recycling amplification
摘要： Abnormal concentration of adenosine triphosphate (ATP) is directly asscociate with several diseases. Thus, sensitive detection of ATP is essential to early diagnosis of disease. Herein, we described an ultrasensitive strategy for ATP detection by using positively charged gold nanorods ((+)AuNPs) as an efficient fluorescence quenching platform, coupled with exonuclease (cid:1) (Exo (cid:1)) assisted target recycling amplification. To construct the sensor, DNA template that contained ATP aptamer was used for the formation of AgNCs signal probe (DNA/AgNCs), the structure of it could change to duplex after the interaction of it with ATP. Such DNA template or duplex DNA product could electrostatically adsorb onto (+)AuNRs surface, resulting in the quenching of the fluorescence signal due to the vicinity of AgNCs to (+)AuNRs. With the addition of Exo (cid:1), DNA duplex could be hydrolyzed and released from (+)AuNRs surface, leading to the recovery of a strong fluorescent signal, while ATP could be regenerated for next target recycling. Combing the good fluorescence quenching ability of (+)AuNRs and the Exo (cid:1) assisted signal amplification, a low detection limit of 26 pM was achieved for ATP detection. Notably, the proposed method can be successfully applied for detecting ATP in serum samples, indicating a potential application value in early cancer diagnosis.
关键词： Exo (cid:1),Fluorescent sensor,(+)AuNRs,DNA/AgNCs,ATP detection,Target recycling amplification
更新于2025-09-16 10:30:52
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An enzyme-free FRET nanoprobe for ultrasensitive ketamine detection based on ATP-fueled target recycling
摘要： Ketamine is a commonly abused drug due to its stimulant, dissociative and hallucinogenic effects. An overdose of ketamine has been found to cause a variety of side effects. Therefore, the identification and quantification of ketamine are of significant importance for clinical purposes and drug seizing. However, conventional methods for ketamine detection possess some disadvantages such as sophisticated procedures, expensive instruments and low sensitivity. Herein, we develop a novel fluorescent nanoprobe for ultrasensitive ketamine detection with signal amplification based on Adenosine Triphosphate (ATP)-fueled target recycling and FRET (fluorescence resonance energy transfer) occurring between the FAM (Fluorescein, tagged with Y-shape DNA) and AuNPs. Based on the combination of FRET and signals circle amplification, the gold nanospheres functionalized with Y-motif DNA (Y@AuNPs) nanoprobe was utilized for effective ketamine detection with the limit of detection (LOD) down to 3 pg mL?1, which was lower than previously reported. Furthermore, the high sensitivity of Y@AuNPs facilitated quantitative analysis in biological media and practical samples.
关键词： Ultrasensitive detection,Ketamine,FRET,ATP-fueled target recycling,Fluorescent nanoprobe
更新于2025-09-16 10:30:52
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All-Waste Hybrid Composites with Waste Silicon Photovoltaic Module
摘要： Nowadays, global warming, energy issues and environmental concern have forced energy production stakeholders to find new low carbon solutions. Photovoltaic technologies as renewable energy resources represent a competitive way for the transition from conventional fossil fuels towards a renewable energy economy. The highest renewable energy systems (RES) market share is based on silicon photovoltaic (Si-PV). The installed RES have rapidly increased over the last two decades, but, after the end of their service life, they will be disposed of. Therefore, the constant increase of the installed RES has attracted the global concern due to their impact on the environment and, most of all, due to the content of their valuable resources. However, the rational management of RES waste has not been addressed so far. The paper represents an extension of a previous work focused on Si-PV recycling by developing all waste hybrid composites. The extension research conducted in this paper is related to the influence of Si-PV characteristics on the mechanical performances and water stability of the hybrid composites. All waste hybrid composites developed by embedding different Si-PV grain sizes were tested before and after water immersion in terms of mechanical strength, interfacial adhesion, crystallinity and morphology by scanning electron microscopy (SEM) analyses. The results revealed the better performance of such Si-PV composites compared to that of sieved composites even after long term water immersion. Therefore, high-content Si-PV hybrid composites could be developed without Si-PV powder sieving. Further on, all waste hybrid composites could be used as paving slabs, protective barriers for outdoor applications.
关键词： silicon photovoltaic module,water stability,all waste hybrid composite materials,interfacial adhesion,recycling,mechanical properties
更新于2025-09-16 10:30:52
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The role of photon recycling in perovskite light-emitting diodes
摘要： Perovskite light-emitting diodes have recently broken the 20% barrier for external quantum efficiency. These values cannot be explained with classical models for optical outcoupling. Here, we analyse the role of photon recycling (PR) in assisting light extraction from perovskite light-emitting diodes. Spatially-resolved photoluminescence and electroluminescence measurements combined with optical modelling show that repetitive re-absorption and re-emission of photons trapped in substrate and waveguide modes significantly enhance light extraction when the radiation efficiency is sufficiently high. In this manner, PR can contribute more than 70% to the overall emission, in agreement with recently-reported high efficiencies. While an outcoupling efficiency of 100% is theoretically possible with PR, parasitic absorption losses due to absorption from the electrodes are shown to limit practical efficiencies in current device architectures. To overcome the present limits, we propose a future configuration with a reduced injection electrode area to drive the efficiency toward 100%.
关键词： external quantum efficiency,light-emitting diodes,photon recycling,optical outcoupling,perovskite
更新于2025-09-16 10:30:52
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Light Shaping for Reconfigurable Microscale Temperature Control
摘要： Recycling rare-earth elements (REEs) from Nd-Fe-B magnet waste is an important step towards building a sustainable REE supply chain. In this study, two different processes were systematically investigated and compared. In the leaching stage, the effect of increasing H2SO4 or HCl concentrations were studied and it was determined that, although both can successfully promote REEs, B, Fe and Co leaching, HCl solutions extracted a wider range of metals. After leaching, the oxalate and double-sulfate precipitation methods were utilized to separate REEs from either HCl or H2SO4 leachates. Results suggest that, although > 99% REEs precipitation rates could be achieved with oxalate, the purity of REE-containing products is significantly affected by impurities like Fe and Co. In contrast, REE double-sulfate precipitation resulted in a product purity of > 99%; however, high levels of Na2SO4 (8 times the stoichiometric amount) were needed to achieve > 98% of REE precipitation.
关键词： rare-earth elements,precipitation,leaching,Nd-Fe-B magnets,recycling
更新于2025-09-12 10:27:22