- 标题
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- 实验方案
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Electrodeposition of hierarchical zinc oxide nanostructures on metal meshes as photoanodes for flexible dye-sensitized solar cells
摘要： Hierarchical zinc oxide (ZnO) nanorod arrays (ZNRAs) were fabricated on stainless steel meshes via a two-step electrodeposition approach as flexible dye-sensitized solar cells (DSSCs) photoanodes. The two-step electrodeposition was realized by deposition of primary ZNRAs followed by growth of secondary branched ZnO nanorods on the primary ZnO nanorods surfaces. The morphologies of ZNRAs and the photovoltaic performances of the assembled DSSCs with different deposition conditions of primary ZNRAs were compared in detail. After modulating electrodeposition conditions, the DSSC assembled with hierarchical ZNRAs obtained an optimum photovoltaic performance with power conversion efficiency of 1.81 %.
关键词： Electrodeposition,Zinc oxide,Stainless steel mesh,Dye-sensitized solar cells,Flexible photovoltaic devices
更新于2025-09-23 15:19:57
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Removal of humic acid from <b>aqueous solutions</b> using ultraviolet irradiation coupled with hydrogen peroxide and zinc oxide nanoparticles
摘要： In this study, individual performance of ultraviolet irradiation (UV), zinc oxide nanoparticles (ZnO) and hydrogen peroxide (H2O2) processes, as well as a performance of combined processes of UV/H2O2 and UV/H2O2/ZnO, were assessed for the removal of humic acid (HA) from aqueous solutions. Various process-related factors, such as the concentration of ZnO (0.2 and 0.5 g/L), the concentration of H2O2 (20, 30 and 50 mg/L), UV = 125 W, pH (4, 7 and 10), initial HA concentrations (at wavelength of 254 nm) of 2, 5, 7 and 10 mg/L, and three types of interferences (nitrate, sulphate and chloride) were studied and optimised. The results showed that removal e?ciency decreased by increasing the concentration of HA and pH values in all processes, but it increased by increasing the time of exposure and the concentration of H2O2. In the combined process of UV/ZnO/H2O2, the nanoparticle concentration of 0.2 g/L yielded the highest e?ciency, whereas in the other processes, the highest e?ciency was observed at nanoparticle concentration of 0.5 g/L. Based on these results, under the optimum conditions (HA = 2 mg/L, H2O2 = 50 mg/L, ZnO = 0.2 g/L, pH = 4.0 and contact time of 15 min), UV/ZnO/H2O2 process was found as the most e?cient combination in removing of HA with an e?ciency of 99.99%. Furthermore, the modelling results indicated that the adsorption reaction of HA onto ZnO nanoparticles was very well described by the pseudo-second-order kinetic model (R2 > 0.99).
关键词： hydrogen peroxide,Ultraviolet irradiation,zinc oxide nanoparticles,humic acid
更新于2025-09-23 15:19:57
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High Performance Organic Solar Cells Fabricated Using Recycled Transparent Conductive Substrates
摘要： The power conversion e?ciency (PCE) of organic solar cells (OSCs) has been gradually increasing over the past years, but these emerging photovoltaic devices still su?er from relatively short lifetimes. To promote circular economy and reduce costly electronic materials wastes, we explore the possibility of recycling durable zinc oxide coated indium tin oxide (ITO/ZnO) from nonfullerene OSCs through sequential ultrasonication in a series of solvents followed by thermal annealing. With the adequate cleaning sequence, the recycled ITO/ZnO substrates produce PCEs of 8.65%, a value comparable to the PCEs obtained with freshly prepared substrates (8.73%). Our results also indicate that isopropanol gradually removes the zinc oxide layer and should thus be avoided when attempting multiple successive recycling of the same substrate. ITO/ZnO substrates recycled 10 times with and without isopropanol yield PCEs of 5.14% and 7.93%, respectively. By optimizing the recycling procedure, we introduce a simple strategy to considerably increase the lifecycle of transparent electrode substrates employed in organic electronic devices and decrease the amount of wastes from the electronic industry.
关键词： Recycling,Zinc oxide,PBDB-T,Organic electronics,Nonfullerene acceptors
更新于2025-09-23 15:19:57
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Amplified Fluorescence by ZnO Nanoparticles vs. Quantum Dots for Bovine Mastitis Acute Phase Response Evaluation in Milk
摘要： Bovine mastitis (BM) is a prominent inflammatory disease affecting the dairy industry worldwide, originated by pathogenic agent invasion onto the mammary gland. The early detection of new BM cases is of high importance for infection control within the herd. During inflammation, various biomarkers are released into the blood circulation, which are consequently found in milk. Herein, the lysosomal activity of N-acetyl-β-D-glucosaminidase (NAGase), a predominant BM indicator, was utilized for highly sensitive clinical state differentiation. The latter is achieved by the precise addition of tetraethyl orthosilicate-coated zinc oxide nanostructures (quantum dots or nanoparticles, individually) onto a conventional assay. Enhanced fluorescence due to the nanomaterial accumulative near-field effect is achieved within real milk samples, contaminated with Streptococcus dysgalactiae, favoring quantum dots over nanoparticles (> 7-fold and 3-fold, respectively), thus revealing significant differentiation between various somatic cell counts. The main advantage of the presented sensing concept, besides its clinically relevant concentrations, is the early bio-diagnostic detection of mastitis (subclinical BM) by using a simple and cost-effective experimental setup. Moreover, the assay can be adapted for BM recovery prognosis evaluation, and thus impact on udder health status, producing an alternative means for conventional diagnosis practices.
关键词： zinc oxide,quantum dots,signal enhancement,mastitis biomarker,nanoparticles,N-acetyl-β-D-glucosaminidase
更新于2025-09-23 15:19:57
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[IEEE 2019 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting - Atlanta, GA, USA (2019.7.7-2019.7.12)] 2019 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting - A Unit-Cell Discontinuous Galerkin Scheme for Analyzing Plasmonic Photomixers
摘要： Disordered ionic-bonded transition metal oxide thin-film transistors (TFTs) show promise for a variety of dc and RF switching applications, especially those that can leverage their low-temperature, substrate-agnostic process integration potential. In this paper, enhancement-mode zinc-oxide TFTs were fabricated and their switching performance evaluated. These TFTs exhibit the drain-current density of 0.6 A/mm and minimal frequency dispersion, as evidenced by dynamic current–voltage tests. A high-frequency power switch figure of merit RON QG of 359 mΩ · nC was experimentally determined for 0.75-μm long-channel devices, and through scaling 45.9 mΩ · nC is achievable for 11 V-rated devices (where RON is ON-state drain–source resistance, and QG is gate charge). An RF switch cutoff frequency fc of 25 GHz was measured for the same 0.75-μm TFT, whereas fc exceeding 500 GHz and power handling in the tens of watts are projected with optimization.
关键词： zinc oxide,dc switch,Cutoff frequency,pulse measurements,gate charge,monolithic ICs,RF switch,ionic semiconductors,thin-film transistors (TFTs)
更新于2025-09-23 15:19:57
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Atomic layer deposition of metal oxides for efficient perovskite single-junction and perovskite/silicon tandem solar cells
摘要： Aluminum-doped and undoped zinc oxide films were investigated as potential front and rear contacts of perovskite single and perovskite/silicon tandem solar cells. The films were prepared by atomic layer deposition (ALD) at low (<200 °C) substrate temperatures. The deposited films were crystalline with a single-phase wurtzite structure and exhibit excellent uniformity and low surface roughness which was confirmed by XRD and SEM measurements. Necessary material characterizations allow for realizing high-quality films with low resistivity and high optical transparency at the standard growth rate. Spectroscopic ellipsometry measurements were carried out to extract the complex refractive index of the deposited films, which were used to study the optics of perovskite single junction and perovskite/silicon tandem solar cells. The optics was investigated by three-dimensional finite-difference time-domain simulations. Guidelines are provided on how to realize perovskite solar cells exhibiting high short-circuit current densities. Furthermore, detailed guidelines are given for realizing perovskite/silicon tandem solar cells with short-circuit current densities exceeding 20 mA cm?2 and potential energy conversion efficiencies beyond 31%.
关键词： Zinc oxide,Tandem solar cells,Perovskite solar cells,Atomic layer deposition,Optical simulations
更新于2025-09-23 15:19:57
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Enhanced efficiency of quantum dot light-emitting diode by sol-gel derived Zn1-xMgxO electron transport layer
摘要： In this study, sol-gel derived Zn1-xMgxO (ZMO) is proposed as an electron transport layer (ETL) for solution-processed quantum-dot light-emitting diodes (QLEDs). It is demonstrated that the increase of Mg content in Zn1-xMgxO films from 0% to 20% causes a dramatic suppression of electron current, which is attributed to the lifting of conduction band minimum and reduction of electron mobility. As a result of Mg-doping, the charge carrier balance might be achieved in the QLED with the Zn0.85Mg0.15O layer resulting in maximum external quantum efficiency of 5.74% and current efficiency of 18 cd·A-1, which are over 3-fold higher than in the case of the device with ZnO layer. Improved device performance is further explained by reduced exciton quenching at QDs/ZMO interface, which is confirmed by time-resolved PL experiments. Obtained results indicate that sol-gel derived ZMO is a promising candidate for ETL in quantum-dot based optoelectronic devices.
关键词： quantum dot,doped zinc oxide,sol-gel process,light-emitting diode,electron transport layer
更新于2025-09-23 15:19:57
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Nanostructured paper-based platform for phenylalanine neonatal screening by LED-induced fluorescence
摘要： In this work, a novel paper-based analytical device (PAD) coupled to LED-induced fluorescence (LIF) detection (fPAD) for the rapid, selective, and sensitive quantification of phenylalanine (Phe) in neonatal samples was developed. Enzymes Phenylalanine dehydrogenase (PheDH) and diaphorase were immobilized on a paper microzone previously modified with zinc oxide nanoparticles (ZnONPs) coated with chitosan (CH-ZnONPs). Phe was extracted from the blood spots collected samples on filter paper and was mixed with nicotinamide adenine dinucleotide (NAD+) and resazurin. Then the mixture was deposited on the reaction microzone of the fPAD where PheDH converts the Phe and NAD+ to phenylpyruvate and NADH, respectively. Finally, NADH was oxidized by diaphorase with the consequent reduction from resazurin to resorufin. This latter was detected by LIF using an excitation wavelength of 535 nm and an emission of 580 nm in a synchronized video microscope. We compare the responses of the PADs with and without nanomaterials to demonstrate the improved analytical performance of the developed devices. For this, the PADs were modified with the same concentration of horseradish peroxidase (HRP). The fluorescent signal obtained from the PADs with nanomaterials was higher than that of the unmodified PADs. Our method exhibited within- and between-assay variation coefficients below 5.23% and 6.67%, respectively. The detection limit obtained by the developed device was 0.125 μM. The proposed fPAD allowed the simple, rapid, low-cost, and sensitive detection of Phe in neonatal blood samples.
关键词： zinc oxide nanoparticles,Phenylalanine,Paper-based analytical device,Enzymatic method,Fluorometric detection
更新于2025-09-23 15:19:57
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Controlled Engineering Nano-sized FeOOH@ZnO Hetero-Structures on Reduced Graphene Oxide for Lithium ion Storage and Photo-Fenton Reaction
摘要： In this work, a nano-sized goethite and zinc oxide hetero-structure (FeOOH@ZnO) dispersed on reduced graphene oxide (RGO) sheets to construct a ternary composite (FeOOH@ZnO/RGO) is first synthesized by a stepped graphene oxide (GO) deoxygenation process. Ferrous ion (Fe2+) and metal Zn were employed as reducing agents, which were transformed to corresponding FeOOH and ZnO nanoparticles to form a hetero-structure in the reaction. Particularly, the size of the nanoparticles can be controlled by limiting the growth kinetics in this work. As a result, porous RGO architecture is constructed with well-dispersed hetero-structured nanoparticles constituted by FeOOH and ZnO nano-crystals encapsulated. The FeOOH@ZnO/RGO composite exhibits unique lithium ion storage properties as anode for lithium ion batteries. And compared with the binary FeOOH/RGO and ZnO/RGO composites, the ternary FeOOH@ZnO/RGO composite shows the best battery performance as anode for lithium ion batteries and the best photo-Fenton degradation activity toward methylene blue (MB) degradation under simulated sunlight irradiation. The preparation route for FeOOH@ZnO/RGO composite is straightforward, effective and has great potential to be scaled-up.
关键词： zinc oxide,goethite,graphene,methylene blue degradation,photo-Fenton,lithium ion batteries
更新于2025-09-23 15:19:57
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[IEEE 2020 IEEE Latin America Electron Devices Conference (LAEDC) - San Jose, Costa Rica (2020.2.25-2020.2.28)] 2020 IEEE Latin America Electron Devices Conference (LAEDC) - New Deposition Technique for Inverted Polymer Solar Cells Using ZnO-ETL
摘要： In this research work, efficient inverted polymer solar cells (iPSCs) were fabricated for the first time using simple and low cost spray pyrolysis (SP) technique to deposit ZnO thin film as electron transporting layer (ETL) with the structure of ITO/ZnO/PTB7-Th: PC70BM/V2O5/Ag. The effect of the different number of running cycles with the SP technique on the iPSC performance has been investigated. In addition, a state of the art for iPSCs fabricated by spin coating technique has been used as reference. In the spray pyrolysis technique, ZnO thin films were fabricated by spraying the ZnO precursor solution onto the pre-heated ITO substrate. Two different numbers of running cycles of ZnO were performed, namely, 15R and 20R. By increasing the running cycles of the sprayed ZnO film, the fill factor and the power conversion efficiency were enhanced by 20% and 32 %, respectively. This improvement might be attributed to enhancing the roughness with compacted film formation and the matched band gap between the active layer (PTB7-Th: PC70BM) and the ZnO-ETL. Hence, this promising spray pyrolysis technique might facilitate the commercialization of polymer solar cells based on mass production besides the possibility of improving its efficiency.
关键词： Polymer solar cells,Spray pyrolysis technique,Zinc Oxide deposition,Electron transporting layer
更新于2025-09-23 15:19:57