Particle Bombardment Research Articles

Effects of supersonic fine particle bombardment on the microstructure and corrosion properties of Ti-6Al-3Nb-2Zr-1Mo alloy

The surface of Ti-6Al-3Nb-2Zr-1Mo (Ti80) alloy was treated with supersonic fine particle bombardment (SFPB) for different time durations from 30 s to 90 s. The effects of different SFPB time on the microstructure and corrosion properties of the specimens were systematically investigated. The surface grains of the specimens with different SFPB treatment time were all refined and formed surface nanostructures, and the surface microhardness increased by 23.9 %, 31.8 % and 39.6 %, respectively, compared with the untreated specimens. After SFPB, compressive residual stress (CRS) was generated in the specimens, with maximum CRS of Ti80 alloy specimens at different SFPB time were −423 MPa, −451 MPa and −487 MPa, respectively. The results of electrochemical and immersion experiments showed that the corrosion rate of SFPB-treated specimens was reduced, and the passivation effect was best at 60 s of SFPB treatment and decreased with the increase of SFPB treatment time. The SFPB treatment improved the corrosion resistance of the specimens, which was the result of the combined effect of grain refinement and surface CRS.

A bifunctional selectable marker for wheat transformation contributes to the characterization of male-sterile phenotype induced by a synthetic Ms2 gene.

An engineered selectable marker combining herbicide resistance and yellow fluorescence contributes to the characterization of male-sterile phenotype in wheat, the severity of which correlates with expression levels of a synthetic Ms2 gene. Genetic transformation of wheat is conducted using selectable markers, such as herbicide and antibiotic resistance genes. Despite their proven effectiveness, they do not provide visual control of the transformation process and transgene status in progeny, which creates uncertainty and prolongs screening procedures. To overcome this limitation, this study developed a fusion protein by combining gene sequences encoding phosphinothricin acetyltransferase and mCitrine fluorescent protein. The fusion gene, introduced into wheat cells by particle bombardment, enabled herbicide selection, and visual identification of primary transformants along with their progeny. This marker was then used to select transgenic plants containing a synthetic Ms2 gene. Ms2 is a dominant gene whose activation in wheat anthers leads to male sterility, but the relationship between the expression levels and the male-sterile phenotype is unknown. The Ms2 gene was driven either by a truncated Ms2 promoter containing a TRIM element or a rice promoter OsLTP6. The expression of these synthetic genes resulted in complete male sterility or partial fertility, respectively. The low-fertility phenotype was characterized by smaller anthers than the wild type, many defective pollen grains, and low seed sets. The reduction in the size of anthers was observed at earlier and later stages of their development. Consistently, Ms2 transcripts were detected in these organs, but their levels were significantly lower than those in completely sterile Ms2TRIM::Ms2 plants. These results suggested that the severity of the male-sterile phenotype was modulated by Ms2 expression levels and that higher levels may be key to activating total male sterility.

Chlorobenzene Mineralization Using Plasma/Photocatalysis Hybrid Reactor: Exploiting the Synergistic Effect

Mineralization of gaseous chlorobenzene (major VOC from cement plants) was studied in a continuous reactor using three advanced oxidation processes: (i) photocatalysis, (ii) Dielectric Barrier Discharge (DBD) plasma and (iii) DBD/TiO2-UV coupling. The work showed an overproduction of OH * and O * radicals in the reaction medium due to the interaction of Cl * and O3. A parametric study was carried out in order to determine the evolution of the removal efficiency as a function of the concentration, the flow rate and the applied voltage. Indeed, a variation of the flow rate from 0.25 to 1 m3/h resulted in a decrease in the degradation rate from 18 to 9%. Similarly, an increase in concentration from 13 to 100 mg/m3 resulted in a change in degradation rate from 18 to 4%. When the voltage was doubled from 6 to 12 kV, the degradation rate varied from 22 to 29 % (plasma) and from 53 to 75% (coupling) at 13 mg/m3. The evolution of COX and O3 was monitored during the experiments. When the voltage was doubled, the selectivity increased from 28 to 37% in the plasma alone and from 48 to 62 % in the coupled process. In addition, at this same voltage range, the amount of ozone formed varied from 10 to 66 ppm in plasma and 3 to 29 ppm in coupling. This degradation performance can be linked to a synergistic effect, which resulted in an increase in the intensity of the electric field of plasma by the TiO2 and the improvement in the performance of the catalyst following the bombardment of various high-energy particles of the plasma.

Plant Virus-Derived Vectors for Plant Genome Engineering.

Advances in genome engineering (GE) tools based on sequence-specific programmable nucleases have revolutionized precise genome editing in plants. However, only the traditional approaches are used to deliver these GE reagents, which mostly rely on Agrobacterium-mediated transformation or particle bombardment. These techniques have been successfully used for the past decades for the genetic engineering of plants with some limitations relating to lengthy time-taking protocols and transgenes integration-related regulatory concerns. Nevertheless, in the era of climate change, we require certain faster protocols for developing climate-smart resilient crops through GE to deal with global food security. Therefore, some alternative approaches are needed to robustly deliver the GE reagents. In this case, the plant viral vectors could be an excellent option for the delivery of GE reagents because they are efficient, effective, and precise. Additionally, these are autonomously replicating and considered as natural specialists for transient delivery. In the present review, we have discussed the potential use of these plant viral vectors for the efficient delivery of GE reagents. We have further described the different plant viral vectors, such as DNA and RNA viruses, which have been used as efficient gene targeting systems in model plants, and in other important crops including potato, tomato, wheat, and rice. The achievements gained so far in the use of viral vectors as a carrier for GE reagent delivery are depicted along with the benefits and limitations of each viral vector. Moreover, recent advances have been explored in employing viral vectors for GE and adapting this technology for future research.

Inter-relationship of stress and microstructure in BCC and ‘beta’ tungsten films

In this work, a series of W films are deposited at different deposition rates (0.2, 0.5, and 1.0 nm/s) and pressures (0.27, 0.47, 0.67, and 1.33 Pa). Comparing the residual stresses between different deposition rates, the stress was found to become more tensile at higher depositions rates over the pressure ranges studied. Films deposited at the three highest pressures were tensile in stress, had small grains (~15 to 20 nm), and stabilized the metastable A15 phase often referred to as β-W. At the lowest pressure, 0.27 Pa, the films were compressive in stress, larger grain sizes (~70 to 90 nm), and primarily stabilized the body centered cubic α-W phase. If a W seed layer was grown under either the α-W or β-W growth conditions, the subsequent W layer adopted the phase state of the seed layer, independent of processing conditions and/or grain sizes, suggesting that the phase state is most likely determined in the initial stages of nucleation. The seed layer experiment also suggest that these layers can promote more controlled grain sizes in thicker β-W films, which has not been observed in previous work. The stress measurements are interpreted in terms of a previously developed kinetic model that includes effects of growth kinetics, microstructural evolution, and energetic particle bombardment.

Efficient genotype-independent cotton genetic transformation and genome editing.

Cotton (Gossypium spp.) is one of the most important fiber crops worldwide. In the last two decades, transgenesis and genome editing have played important roles in cotton improvement. However, genotype dependence is one of the key bottlenecks in generating transgenic and gene-edited cotton plants through either particle bombardment or Agrobacterium-mediated transformation. Here, we developed a shoot apical meristem (SAM) cell-mediated transformation system (SAMT) that allowed the transformation of recalcitrant cotton genotypes including widely grown upland cotton (Gossypium hirsutum), Sea island cotton (Gossypium barbadense), and Asiatic cotton (Gossypium arboreum). Through SAMT, we successfully introduced two foreign genes, GFP and RUBY, into SAM cells of some recalcitrant cotton genotypes. Within 2-3 months, transgenic adventitious shoots generated from the axillary meristem zone could be recovered and grown into whole cotton plants. The GFP fluorescent signal and betalain accumulation could be observed in various tissues in GFP- and RUBY-positive plants, as well as in their progenies, indicating that the transgenes were stably integrated into the genome and transmitted to the next generation. Furthermore, using SAMT, we successfully generated edited cotton plants with inheritable targeted mutagenesis in the GhPGF and GhRCD1 genes through CRISPR/Cas9-mediated genome editing. In summary, the established SAMT transformation system here in this study bypasses the embryogenesis process during tissue culture in a conventional transformation procedure and significantly accelerates the generation of transgenic and gene-edited plants for genetic improvement of recalcitrant cotton varieties.

The Role of a Soybean 14-3-3 Gene (Glyma05g29080) on White Mold Resistance and Nodulation Investigations Using CRISPR-Cas9 Editing and RNA Silencing.

The role of a soybean 14-3-3 gene (Glyma05g29080) in defense against white mold and in nodulation was investigated by loss-of-gene-function with CRISPR-Cas9 editing and silencing of RNA interference (RNAi). Particle bombardment was used to introduce the CRISPR expression cassette to target the soybean 14-3-3 gene and an RNAi construct to silence gene transcription. Transmission of the edited 14-3-3 gene and the RNAi construct was confirmed in their respective progeny. The recovered transgenic plants and their progeny were significantly more susceptible to Sclerotinia sclerotiorum infection and showed a significant reduction in nodulation, thus confirming the role of the 14-3-3 gene (Glyma05g29080) in both nodulation and defense.

Neutronics Assessment of the Spatial Distributions of the Nuclear Loads on the DEMO Divertor ITER-like Targets: Comparison between the WCLL and HCPB Blanket

The Plasma Facing Components (PFCs) of the divertor target contribute to the fundamental functions of heat removal and particle exhaust during fusion operation, being subjected to a very hostile and complex loading environment characterized by intense particles bombardment, high heat fluxes (HHF), varying stresses loads and a significant neutron irradiation. The development of a well-designed divertor target, which represents a crucial step in the realization of DEMO, needs the assessment of all these loads as accurately as possible, to provide pivotal data and indications for the design and structural performance prediction of the PFCs. In a particular way, this study is fully devoted to the comprehension of the distributions on the divertor target of the main nuclear loads due to neutron irradiation, performed for the first time using an extremely detailed approach. This work has been carried-out considering the latest configuration of the DEMO reactor, including the updated design of the divertor and ITER-Like PFCs geometry, varying the blanket layout (Water Cooled Lithium Lead—WCLL and Helium Cooled Pebble Bed—HCPB), thus evaluating the impact of the different blanket concept on the above-mentioned distributions. Neutronics analyses have been performed with MCNP5 Monte Carlo code and JEFF3.3 nuclear data libraries. 3D DEMO MCNP models have been created, focusing in particular on a thorough representation of the divertor and PFCs, allowing for the assessment of the distributions of the main nuclear loads: radiation damage (dpa/FPY), He-production rate (appm/FPY) and nuclear heating density (W/cm3) and total nuclear power deposition (MW). These results are presented by means of 2D maps and plots for each PFCs sub-component both for WCLL and HCPB blanket case: W-monoblocks, Cu-interlayers\CuCrZr-pipe and PFC-CB (Cassette Body) supports made of Eurofer steel.

Sulfur chemistry on the surface ice of Europa

Because Europa is embedded in Jupiter's magnetosphere, Europa's crust, which is mainly made of water ice, is continuously bombarded by energetic ions and electrons. The bombardment of the energetic particles not only sputters and dissociates water molecules on Europa's surface but also introduces impurities to its surface ice. Especially, sulfur ions deliver sulfur to the ice, which induces further chemical reactions in the ice and leads to the formation of sulfur-containing species. Observational and experimental studies have shown that sulfuric acid is formed from the sulfur ion implantation on ice. However, the sulfur chemistry on the surface ice of Europa is still poorly understood. In this study, we use a chemical-transport model to simulate chemical processes occurring in the surface ice of Europa during irradiation by ions and electrons. We show that sulfuric acid is the dominant species on the surface ice of Europa, whose mixing ratio may be as high as several percent in the first 100 μm of the ice. We also find that sulfur chemistry may play an important role in the formation of O2 on the surface ice of Europa. The results of our model can be used to estimate the transport rate of the key species (e.g., O2, H2O2, H2SO4) from Europa's surface ice to its subsurface ocean.

Genetic transformation and gene delivery strategies in <i>Carica papaya</i> L.

Papaya (<italic>Carica papaya</italic> L.) is a popular tropical fruit of high commercial value due to its nutritional, medicinal and industrial properties. However, conventional breeding methods for papaya have several limitations, including a scarcity of natural genetic resources in the <italic>Carica</italic> genus and sexual incompatibility among closely-related species. To overcome these challenges, particle bombardment, agrobacterium-mediated transformation, and pollen tube-mediated transformation have been developed for generating genetically modified papaya with the desired traits over the past three decades. These transformation methods have been successfully employed to improve papaya's resistance to biotic and abiotic stress, fruit quality, and even to produce edible vaccines. Notably, papaya ringspot virus-resistant transgenic papaya is the first successful commercial application of genetic engineering technology in a fruit crop. Recently, CRISPR/Cas9-mediated genome editing technology and viral vector-based gene delivery system have emerged as promising tools for papaya genetic improvement and functional genomic studies in papaya. Genome editing will open a new era of precision breeding for papaya. This review aims to highlight past and recent gene transformation methods and their applications in papaya breeding, as well as future perspectives and challenges in improving papaya via genetic engineering.

Inoculation of Maize with Sugarcane Mosaic Virus Constructs and Application for RNA Interference in Fall Armyworms.

Virus-mediated transient gene overexpression and gene expression silencing can be used to screen gene functions in plants. Sugarcane mosaic virus (SCMV) is a positive strand RNA virus in the Potyviridae family that has been modified to be used as vector to infect monocots, including maize (Zea mays), for transient gene overexpression and gene expression silencing. Relative to stable transformation, SCMV-mediated transient expression in maize has the advantages of being faster and less expensive. Here, we describe a protocol for cloning constructs into the plasmid vector pSCMV-CS3. After maize seedlings are transformed with pSCMV-CS3 constructs by particle bombardment, the virus replicates and spreads systemically in the plants. Subsequent infections of maize seedlings can be accomplished by rub inoculation with sap from SCMV-infested plants. As an example of a practical application of the method, we also describe virus-induced gene silencing (VIGS) of fall armyworm (Spodoptera frugiperda) gene expression. Transgenic viruses are created by cloning a segment of the fall armyworm target gene into pSCMV-CS3 prior to maize transformation. Caterpillars are fed on the virus-infected maize plants, which make dsRNA to silence the expression of the fall armyworm target gene after ingestion. This use of SCMV for plant-mediated VIGS in insects allows rapid screening of gene functions when caterpillars are feeding on their host plants. Graphical overview.

Transformation and gene editing in the bioenergy grass Miscanthus

BackgroundMiscanthus, a C4 member of Poaceae, is a promising perennial crop for bioenergy, renewable bioproducts, and carbon sequestration. Species of interest include nothospecies M. x giganteus and its parental species M. sacchariflorus and M. sinensis. Use of biotechnology-based procedures to genetically improve Miscanthus, to date, have only included plant transformation procedures for introduction of exogenous genes into the host genome at random, non-targeted sites.ResultsWe developed gene editing procedures for Miscanthus using CRISPR/Cas9 that enabled the mutation of a specific (targeted) endogenous gene to knock out its function. Classified as paleo-allopolyploids (duplicated ancient Sorghum-like DNA plus chromosome fusion event), design of guide RNAs (gRNAs) for Miscanthus needed to target both homeologs and their alleles to account for functional redundancy. Prior research in Zea mays demonstrated that editing the lemon white1 (lw1) gene, involved in chlorophyll and carotenoid biosynthesis, via CRISPR/Cas9 yielded pale green/yellow, striped or white leaf phenotypes making lw1 a promising target for visual confirmation of editing in other species. Using sequence information from both Miscanthus and sorghum, orthologs of maize lw1 were identified; a multi-step screening approach was used to select three gRNAs that could target homeologs of lw1. Embryogenic calli of M. sacchariflorus, M. sinensis and M. x giganteus were transformed via particle bombardment (biolistics) or Agrobacterium tumefaciens introducing the Cas9 gene and three gRNAs to edit lw1. Leaves on edited Miscanthus plants displayed the same phenotypes noted in maize. Sanger sequencing confirmed editing; deletions in lw1 ranged from 1 to 26 bp in length, and one deletion (433 bp) encompassed two target sites. Confocal microscopy verified lack of autofluorescence (chlorophyll) in edited leaves/sectors.ConclusionsWe developed procedures for gene editing via CRISPR/Cas9 in Miscanthus and, to the best of our knowledge, are the first to do so. This included five genotypes representing three Miscanthus species. Designed gRNAs targeted all copies of lw1 (homeologous copies and their alleles); results also confirmed lw1 made a good editing target in species other than Z. mays. The ability to target specific loci to enable endogenous gene editing presents a new avenue for genetic improvement of this important biomass crop.Graphical

Mechanical Properties and Formation Mechanism of Surface Hard Nanocrystalline Carbon Diffusion Layer on 18Cr2Ni4WA Steel Induced by Supersonic Fine Particle Bombarding

Mechanical Properties and Formation Mechanism of Surface Hard Nanocrystalline Carbon Diffusion Layer on 18Cr2Ni4WA Steel Induced by Supersonic Fine Particle Bombarding

Rapid Construction of LTO/CuO Heterojunctions by Active Screen Plasma for Excellent Lithium-Ion Storage

The lower intrinsic capacity and electron/ion transfer rate of Li4Ti5O12 limit its application and commercialization in high-specific-energy batteries. In this work, Li4Ti5O12/CuO heterojunctions are constructed by depositing CuO ultrafine nanoparticles on Li4Ti5O12 nanosheets using a controllable and high-efficiency active screen plasma (ASP) technique. It is found that the rich interface and built-in electric field provided by the heterojunction enhance the electron conductivity and ionic conductivity, and density functional theory calculations confirm that the heterojunction reduces the band gap and enhances the adsorption energy for lithium ions; in the lithium storage process, the conversion reaction between CuO and lithium ions not only provides additional capacity but also the product Cu facilitates electron transport and accelerates the electrochemical process. In addition, the increase in vacancies and specific surface area due to high-energy particle bombardment contributes to the increase in conductivity and the number of active sites, and the treated sample exhibits excellent reversible capacity (182.6 mAh·g–1 at 1C), high rate performance (170.6 mAh·g–1 at 30C), and long cycle stability (136.7 mAh·g–1 after 4500 cycles at 20C) in the half-cell, and the full cell assembled with NMC811 maintained 227.4 mAh·g–1 after 700 cycles at 1C.

An established protocol for generating transgenic wheat for wheat functional genomics via particle bombardment.

Wheat is one of the most important food crops in the world and is considered one of the top targets in crop biotechnology. With the high-quality reference genomes of wheat and its relative species and the recent burst of genomic resources in Triticeae, demands to perform gene functional studies in wheat and genetic improvement have been rapidly increasing, requiring that production of transgenic wheat should become a routine technique. While established for more than 20 years, the particle bombardment-mediated wheat transformation has not become routine yet, with only a handful of labs being proficient in this technique. This could be due to, at least partly, the low transformation efficiency and the technical difficulties. Here, we describe the current version of this method through adaptation and optimization. We report the detailed protocol of producing transgenic wheat by the particle gun, including several critical steps, from the selection of appropriate explants (i.e., immature scutella), the preparation of DNA-coated gold particles, and several established strategies of tissue culture. More importantly, with over 20 years of experience in wheat transformation in our lab, we share the many technical details and recommendations and emphasize that the particle bombardment-mediated approach has fewer limitations in genotype dependency and vector construction when compared with the Agrobacterium-mediated methods. The particle bombardment-mediated method has been successful for over 30 wheat genotypes, from the tetraploid durum wheat to the hexaploid common wheat, from modern elite varieties to landraces. In conclusion, the particle bombardment-mediated wheat transformation has demonstrated its potential and wide applications, and the full set of protocol, experience, and successful reports in many wheat genotypes described here will further its impacts, making it a routine and robust technique in crop research labs worldwide.

Bait microalga harboring antimicrobial peptide for controlling Vibrio infection in Argopecten irradians aquaculture

Vibrio infection is a longstanding and serious bacterial disease of various shellfish species that has caused high mortality rates for many decades. Antibiotics can effectively prevent and control bacterial diseases. However, the long-term abuse of antibiotics exacerbates the risk of environmental pollution, which also poses a threat to food safety. In this study, transgenic lines of the marine microalga Tetraselmis subcordiformis harboring antimicrobial peptide NZ2114 were attempted to be created as an oral drug-delivery system in shellfish aquaculture. Toward this, codon-optimized nz2114 was respectively assembled into nuclear and chloroplast expression vectors of T. subcordiformis. After particle bombardment, two stable transgenic lines Y1 (with nuclear transformation) and Y2 (with chloroplast transformation) were selected, each expressing a stable transgene inheritance for at least 12 months. In vitro experiments demonstrated the significant inhibition of total protein containing NZ2114 from transgenic lines on two marine Vibrio species and Staphylococcus aureus. To test the efficacy of transgenic baits, pathogen-infected scallops (Argopecten irradians) were fed with transgenic T. subcordiformis via oral delivery. The results showed that the survival rate (after 20 days of infection) of the scallops fed transgenic T. subcordiformis was much higher than that of scallop fed with wild-type algae (95.92% versus 80.41%). In summary, this strategy offers a new, efficient, and low-cost method for controlling Vibrio in scallop aquaculture through oral drug-delivery system, which is a promising step toward the development of safe and environment-friendly antimicrobial baits.

Enhanced impact and wear properties of gear steel by supersonic fine particle bombardment modification technology

In this work, the wear resistance and impact toughness of the carburized layer were improved by rare earth (RE) doped supersonic fine particle bombardment (SFPB) pretreatment assisted vacuum carburizing. On the surface of 17CrNiMo6 steel, vacuum carburizing (VC), SFPB vacuum carburizing (SC), and CeO2 doped SFPB vacuum carburizing (CSC) layers were formed, respectively. The effect of SFPB and CeO2 doping SFPB pretreatment on microstructure, impact toughness and wear resistance of carburized layers were investigated in detail. Results show that the microstructure of the CSC layer changes obviously, and equiaxed martensite and nano carbide are formed on the surface. The surface impact toughness and wear resistance of the SC layer and the CSC layer are significantly improved, compared with that of the VC layer. In particular, the impact absorbed energy of CeO2 doping SFPB carburized (CSC) (60.8 J) was 30.8% higher than that of the VC (46.5 J), which is attributed to the refinement of martensite and austenite by pretreatment. Among the carburized layers, the modified carburized layer doped with CeO2 (CSC) had the minimum wear rate (9.45 × 10−15m3N−1 m−1), indicating the strongest resistance to wear. Meanwhile, the wear rate of the CSC layer was increased by 11% compared to that of the VC layer. Moreover, the main wear mechanism of various carburizing layers was abrasive wear.

Biotechnological intervention in genetic improvement and regulation of secondary metabolites production in Ocimum sanctum L

Ocimum sanctum L. is the most significant wellspring of medications utilized in the pharmaceutical industries and in the field of medicine. O. sanctum has a distinctive combination of pharmacological actions that support resilience and wellbeing. The secondary metabolites of O. sanctum show beneficial effects in the treatment of various diseases. This plant contains anti-oxidant properties and high amount of phenolic compounds which protect the body from toxin-induced damage. Due to its very high demand and less yield of the pharmaceutical content or secondary metabolites, there has been a persistent need to improve the productivity of the plant by using modern technology. There are various biotechnological methodologies which are utilized for the genetic improvement of this therapeutic plants viz micropropagation, direct or indirect in vitro regeneration, secondary metabolite enhancement by different types of elicitors, somatic embryogenesis and genetic transformation by various gene transfer approaches like Agrobacterium tumefiaciens, particle bombardment, etc. Genetic engineering for improvement of production of secondary metabolite and its biosynthesis pathways by overexpressing vital genes involved in the metabolite biosynthesis were reviewed. Omics techniques were also studied for understanding the genome structure, candidate genes and candidate proteins involved in secondary metabolites production. Overall, this review paper discusses the application of biotechnological techniques for enhancement of secondary metabolites production in O. sanctum.

Bathocuproine:Ag Complex Functionalized Tunneling Junction for Efficient Monolithic Perovskite/TOPCon Silicon Tandem Solar Cell

The single‐crystalline silicon solar cell with tunnel oxide passivating poly‐Si contact (TOPCon) has developed into one of the most promising and high‐performance n‐type Si‐based solar cells in their mass production way because of its high conversion efficiency and robustness. Owing to its unique device structure, TOPCon shows superior advantages over amorphous Si‐based heterojunction one (HJT) in developing high‐performance monolithic perovskite/silicon tandem solar cell because TOPCon may have better tolerance than HJT to the particle bombardments and plasma fluorescence irradiations in the sputtering deposition process of transparent conductive oxide (TCO) recombination layer. Herein, bathocuproine (BCP):silver complex is introduced as a buffer recombination contact between TCO and poly‐SiCX, to modulate the tunneling junction between perovskite/TOPCon. Depending on fine film thickness and derived energy level tuning, BCP:Ag buffer layer can effectively prevent the sputter bombardments and passivate the interface of TCO/poly‐SiCX(n)/SiOX contact, as well as enhancing electron transport. As a result, a certified conversion efficiency of 25.84% is achieved in the monolithic perovskite/TOPCon silicon tandem solar cell. This work definitely paves a new and promising way to develop high‐performance monolithic perovskite/c‐Si tandem solar cells.

Spectroscopic investigation of the tungsten deuteride sputtering in the EAST divertor

• Behaviors of WD molecules sputtering were compared with W atoms sputtering in EAST. • Existence of energy threshold for WD sputtering in EAST was discussed. • Influences of heat flux and D retention on WD sputtering in EAST were analyzed in detail. Physical sputtering caused by particle bombardment is believed to be the main erosion mechanism of W materials in fusion devices, in which W atoms are the sputtering products. However, the tungsten deuteride molecule (WD) spectra have been observed in both TEXTOR and ASDEX Upgrade, which was believed to be the product of chemically assisted physical sputtering (CAPS), a new sputtering mechanism that has been proposed in recent years. In this paper, we report the spectroscopic observation of WD molecules in the EAST W divertor. The behaviors of WD molecules sputtering are compared with W atoms sputtering via the spectral measurements of the ro-vibrational band emission of WD 6 Π → 6 Σ + in the spectral range between 673 nm and 678 nm and the WI line emission at 400.9 nm. The physical sputtering characters and chemical sputtering characters of WD molecule sputtering were confirmed in EAST. The measurements in EAST showed that there is an energy threshold for WD molecules sputtering and that the sputtering energy threshold of WD molecules is smaller than that of W atoms. Furthermore, the dependence of WD molecule sputtering efficiency (the absolute WD photon flux ( Ph WD ) normalized to the particle flux ( Γ ion ) reaching the target with a constant T e ) on impact energy and heat flux were studied, presenting significantly different behaviors compared with W atom sputtering. In addition, it is found that the decrease of WD sputtering efficiency with the heat flux is accompanied by the rise of the photon flux of D δ (410.06 nm) normalized to the particle flux ( Γ ion ) at the divertor target, which may imply the enhanced deuterium desorption at the W surface. The further increase of heat flux hitting the target surface could elevate the surface temperature and benefit the deuterium release from the surface, which may influence the formation of WD molecules at the surface layer.