CuInS2 Photocathodes with Atomic Gradation-Controlled (Ta,Mo)x(O,S)y Passivation Layers for Efficient Photoelectrochemical H2 Production

2021 ◽  
Author(s):  
Sang Youn Chae ◽  
Yoolim Kim ◽  
Eun Duck Park ◽  
Sang Hyuk Im ◽  
Oh-Shim Joo
Keyword(s):  
H2 Production ◽  
Passivation Layers

PERLAKUAN ETHYL METHANE SULFONATE (EMS) PADA ENTEROBACTER AEROGENES AY-2 DARI LIMBAH METAN FERMENTASI UNTUK PENINGKATAN PRODUKSI GAS HIDROGEN

2018 ◽  
Vol 5 (1) ◽  
Author(s):  
Mahyudin Abdul Rachman
Keyword(s):  
Metabolic Pathway ◽  
Acid Production ◽  
Double Mutant ◽  
Enterobacter Aerogenes ◽  
H2 Production ◽  
Hydrogen Gas ◽  
Survival Ratio ◽  
Ethyl Methane Sulfonate ◽  
Methane Sulfonate ◽  
Ethyl Methane

Enterobacter aerogenes AY-2 mutant is known for hydrogen gas producer which ws obtained from the sludge of methane fermentation and the yield is 1.5 fold higher than wildtype. Hydrogen gas production can be gain via NADH oxidation in anaerobic metabolic pathway by blocking organic acid production. Metabolic pathway can be changed by mutagenesis. Enterobacter aerogenes AY-2 mutated with ethyl methane sulfonate in logarithmic phase with consentration 10, 11, 12, 13, 14 and 15 μl/ml cell suspention during 120 minute. Mutation that result lowest survival ratio (0,01%) was 14 μl EMS/ml cell suspention is repeated with variation incubation time, 30, 60, 90 and 120 minute. 166 double mutant colony has been collected and choosen randomly. The choosen 43 colony was fermented in glycerol complex medium for determining ten double mutant with the highest H2 production. Double mutant AD-H43 is a highest H2 producer that increase 20% H2 production from AY-2 and has a decrease lactid acid production, 31% less from AY-2. Increasing H2 production in double mutant AD-H43 is caused by lactate dehydrogenase deffi cient.Keywords: Enterobacter aerogenes AY-2, ethyl methane sulfonate (EMS), H2 and methane sludge

Localized Die Metallization Damage Induced During Laser-Marking of a Semiconductor Package

2007 ◽  
Author(s):  
Paul Eric B. Parañal
Keyword(s):  
Laser Beam ◽  
Direct Interaction ◽  
Silica Spheres ◽  
Layer By Layer ◽  
Laser Marking ◽  
Molding Compound ◽  
Molding Material ◽  
Die Surface ◽  
Passivation Layers ◽  
Propagation Medium

Abstract This paper presents a new fail mechanism for laser-marking induced die damage. Discovered during package qualification, silica spheres – commonly used as fillers in the molding material, was shown to act as a propagation medium that promote the direct interaction of the scribing laser beam and the die surface. Critical to the understanding of the fail mechanism is the deprocessing technique devised to allow layer by layer examination of the metallization and passivation layers in an encapsulated silicon die. The technique also made possible the inspection of the molding compound profile directly on top of the affected die area.

Studies on a Novel Qualification Method of Silicon Nitride Layer

2016 ◽  
Author(s):  
Younan Hua ◽  
Bingsheng Khoo ◽  
Henry Leong ◽  
Yixin Chen ◽  
Eason Chan ◽  
...  
Keyword(s):  
Silicon Nitride ◽  
Silicon Substrate ◽  
Nitride Layer ◽  
Passivation Layer ◽  
Wafer Fabrication ◽  
Wafer Surface ◽  
Si3n4 Layer ◽  
Silicon Nitride Layer ◽  
Passivation Layers ◽  
Pinhole Test

Abstract In wafer fabrication, a silicon nitride (Si3N4) layer is widely used as passivation layer. To qualify the passivation layers, traditionally chemical recipe PAE (H3PO4+ HNO3) is used to conduct passivation pinhole test. However, it is very challenging for us to identify any pinholes in the Si3N4 layer with different layers underneath. For example, in this study, the wafer surface is Si3N4 layer and the underneath layer is silicon substrate. The traditional receipt of PAE cannot be used for passivation qualification. In this paper, we will report a new recipe using KOH solution to identify the pinhole in the Si3N4 passivation layer.

scholarly journals MoS2 Based Photodetectors: A Review

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2758
Author(s):  
Alberto Taffelli ◽  
Sandra Dirè ◽  
Alberto Quaranta ◽  
Lucio Pancheri
Keyword(s):  
Electric Fields ◽  
Spectral Range ◽  
Performance Metrics ◽  
Transition Metal Dichalcogenides ◽  
Visible Spectral Range ◽  
Detector Performance ◽  
Strong Light ◽  
Near Ultraviolet ◽  
Passivation Layers ◽  
Low Dimensional

Photodetectors based on transition metal dichalcogenides (TMDs) have been widely reported in the literature and molybdenum disulfide (MoS2) has been the most extensively explored for photodetection applications. The properties of MoS2, such as direct band gap transition in low dimensional structures, strong light–matter interaction and good carrier mobility, combined with the possibility of fabricating thin MoS2 films, have attracted interest for this material in the field of optoelectronics. In this work, MoS2-based photodetectors are reviewed in terms of their main performance metrics, namely responsivity, detectivity, response time and dark current. Although neat MoS2-based detectors already show remarkable characteristics in the visible spectral range, MoS2 can be advantageously coupled with other materials to further improve the detector performance Nanoparticles (NPs) and quantum dots (QDs) have been exploited in combination with MoS2 to boost the response of the devices in the near ultraviolet (NUV) and infrared (IR) spectral range. Moreover, heterostructures with different materials (e.g., other TMDs, Graphene) can speed up the response of the photodetectors through the creation of built-in electric fields and the faster transport of charge carriers. Finally, in order to enhance the stability of the devices, perovskites have been exploited both as passivation layers and as electron reservoirs.

scholarly journals An Overview on Anodes for Magnesium Batteries: Challenges towards a Promising Storage Solution for Renewables

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 810
Author(s):  
Federico Bella ◽  
Stefano De Luca ◽  
Lucia Fagiolari ◽  
Daniele Versaci ◽  
Julia Amici ◽  
...  
Keyword(s):  
Reduction Potential ◽  
Literature Analysis ◽  
Organic Electrolytes ◽  
Boron Clusters ◽  
Passivation Film ◽  
Metallic Magnesium ◽  
Passivation Layers ◽  
Magnesium Batteries ◽  
Nanostructured Metal Oxides ◽  
Nanostructured Metal

Magnesium-based batteries represent one of the successfully emerging electrochemical energy storage chemistries, mainly due to the high theoretical volumetric capacity of metallic magnesium (i.e., 3833 mAh cm−3 vs. 2046 mAh cm−3 for lithium), its low reduction potential (−2.37 V vs. SHE), abundance in the Earth’s crust (104 times higher than that of lithium) and dendrite-free behaviour when used as an anode during cycling. However, Mg deposition and dissolution processes in polar organic electrolytes lead to the formation of a passivation film bearing an insulating effect towards Mg2+ ions. Several strategies to overcome this drawback have been recently proposed, keeping as a main goal that of reducing the formation of such passivation layers and improving the magnesium-related kinetics. This manuscript offers a literature analysis on this topic, starting with a rapid overview on magnesium batteries as a feasible strategy for storing electricity coming from renewables, and then addressing the most relevant outcomes in the field of anodic materials (i.e., metallic magnesium, bismuth-, titanium- and tin-based electrodes, biphasic alloys, nanostructured metal oxides, boron clusters, graphene-based electrodes, etc.).

scholarly journals Efficient Sequestration of Hexavalent Chromium by Graphene-Based Nanoscale Zero-Valent Iron Composite Coupled with Ultrasonic Pretreatment

2021 ◽  
Vol 18 (11) ◽  
pp. 5921
Author(s):  
Haiyan Song ◽  
Wei Liu ◽  
Fansheng Meng ◽  
Qi Yang ◽  
Niandong Guo
Keyword(s):  
Aqueous Solution ◽  
Removal Efficiency ◽  
Inhibitory Effect ◽  
Ultrasonic Cavitation ◽  
Zero Valent Iron ◽  
Ultrasonic Pretreatment ◽  
Nanoscale Zero Valent Iron ◽  
Passivation Layers ◽  
Initial Ph ◽  
Two Phases

Nanoscale zero-valent iron (nZVI) has attracted considerable attention for its potential to sequestrate and immobilize heavy metals such as Cr(VI) from an aqueous solution. However, nZVI can be easily oxidized and agglomerate, which strongly affects the removal efficiency. In this study, graphene-based nZVI (nZVI/rGO) composites coupled with ultrasonic (US) pretreatment were studied to solve the above problems and conduct the experiments of Cr(VI) removal from an aqueous solution. SEM-EDS, BET, XRD, and XPS were performed to analyze the morphology and structures of the composites. The findings showed that the removal efficiency of Cr(VI) in 30 min was increased from 45.84% on nZVI to 78.01% on nZVI/rGO and the removal process performed coupled with ultrasonic pretreatment could greatly shorten the reaction time to 15 min. Influencing factors such as the initial pH, temperature, initial Cr(VI) concentration, and co-existing anions were studied. The results showed that the initial pH was a principal factor. The presence of HPO42−, NO3−, and Cl− had a strong inhibitory effect on this process, while the presence of SO42− promoted the reactivity of nZVI/rGO. Combined with the above results, the process of Cr(VI) removal in US-nZVI/rGO system consisted of two phases: (1) The initial stage is dominated by solution reaction. Cr(VI) was reduced in the solution by Fe2+ caused by ultrasonic cavitation. (2) In the following processes, adsorption, reduction, and coprecipitation coexisted. The addition of rGO enhanced electron transportability weakened the influence of passivation layers and improved the dispersion of nZVI particles. Ultrasonic cavitation caused pores and corrosion at the passivation layers and fresh Fe0 core was exposed, which improved the reactivity of the composites.

Metabolically versatile Rhodobacter sphaeroides as a robust biocatalyst for H2 production from lignocellulose-derived mix substrates

Fuel ◽  
2021 ◽  
Vol 302 ◽  
pp. 121108
Author(s):  
Jun Hu ◽  
Wenwen Wei ◽  
Qing Li ◽  
Wen Cao ◽  
Anlong Zhang ◽  
...  
Keyword(s):  
Rhodobacter Sphaeroides ◽  
H2 Production
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