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Low Temperature Solution-Processable 3D-Patterned Charge Recombination Layer for Organic Tandem Solar Cells

Low Temperature Solution-Processable 3D-Patterned Charge Recombination Layer for Organic Tandem Solar Cells

Keywords: organic tandem solar cell; 3D nano-ripple pattern; ZnO sol-gel; charge recombination layer; low temperature solution process 1. Introduction Finding alternatives for the current energy sources (i.e., burning fossil fuels, nuclear materials) has become one of the most important societal challenges for relieving the environmental pollution problem [ 1 ]. One of the most promising next-generation energy sources is solar energy, which can be converted to electric power via photovoltaic technology. Currently industrialized photovoltaic panels are based on inorganic materials such as silicon [ 2 – 4 ]. Recently, organic solar cells (OSCs) emerged as an alternative to inorganic photovoltaics devices [ 5 – 7 ]. The merits of OSC technology are: a low-cost solution process, a low temperature process, flexibility, and a tailorable material for further improvement. Recently, the champion single-junction OSC has reached a power conversion efficiency (PCE) of 12.6% [ 8 ]. However, it is still necessary for improving PCE and air-stability for large-scale commercialization.
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Low‐Temperature & Transfer‐Free Graphene Growth: Process and Underlying Mechanisms

Low‐Temperature & Transfer‐Free Graphene Growth: Process and Underlying Mechanisms

Figure 3. 2. GNR-based FETs characteristics (a) SEM image of GNR devices fabricated on a 200 nm-thick SiO 2 substrate. Temperature-dependent electrical characteristics as a function of gate voltage with (b) 100 nm, (c) 20 nm width of GNR, respectively. Cited from Z. Chen et al., Physica E 40, 228-232 (2007) 54 In 2008, a chemical route to produce GNR with width below 10 nm has been developed by Stanford University 55, 56 . Unlike single-walled carbon nanotubes (SWCNTs), all of the sub-10 nm GNRs produced were semiconductors and afforded graphene filed effect transistors with on/off ratios of about 10 7 at room temperature. They exfoliated commercial expandable graphite by brief heating to 1000 o C in forming gas. The resulting exfoliated graphite was dispersed in a 1,2-dichloroethane (DCE) solution of poly(m- phenylenevinylene-co-2,5-dioxtoxy-p-phenylenevinylene) (PmPV) by sonication for 30 min to form a homogeneous suspension. Centrifugation then removed large pieces of materials from the supernatant. Room temperature on/off current switching (I on /I off ) induced by the gate voltage increased exponentially as the GNR
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Hydrodeoxygenation Using Magnetic Induction: High-Temperature Heterogeneous Catalysis in Solution

Hydrodeoxygenation Using Magnetic Induction: High-Temperature Heterogeneous Catalysis in Solution

in all the cases studied), which can be of interest in terms of scalability of the process. Finally, furfural and HMF, two platform molecules derived from biomass, were successfully and very selectively transformed into the corresponding alkylfurans 2-MF and 2,5-DMF respectively. This may be of further interest to perform selective oxygen removal avoiding ring-opening of heterocyclic molecules. In conclusion, these results prove the high potential of magnetic heating of magnetic NPs for catalysis in solution and, in the context of biomass valorization, demonstrate that using this new approach, the reactions can be performed very selectively under much milder conditions, and remarkably, very low pressures of H 2 .
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Preparation of nitrogen doped zinc oxide nanoparticles and thin films by colloidal route and low temperature nitridation process

Preparation of nitrogen doped zinc oxide nanoparticles and thin films by colloidal route and low temperature nitridation process

After distillation of 9 mL of the as-obtained solution in a preheated (125°C) oil bath of a rotary evaporator, 9 mL of tetramethylammonium hydroxide (TMAOH) in methanol (Alfa Aesar, 25 % w/w in methanol) were rapidly added in the still hot solution. This addition induced the formation of a turbid solution which immediately disappeared after a strong agitation, the mixture being transformed into a clear colloidal suspension. This solution was kept 24 hours under magnetic stirring before being precipitated with 80 mL of diethyl ether (Carlo Erba, 99.8%). The white ZnO powders were separated by centrifugation (12 000 rpm during 5 min) and were dried with acetone to obtain ZnO nanoparticles.
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Chromium carbide growth at low temperature by a highly efficient DLI-MOCVD process in effluent recycling mode

Chromium carbide growth at low temperature by a highly efficient DLI-MOCVD process in effluent recycling mode

In this paper, “new” coatings refer to coatings elaborated using a freshly prepared liquid solution of as-received precursor and solvent, while “recycled” coatings concern coatings deposited using directly a recycled liquid solution of precursor, by-products and solvent. The same experimental parameters were used for new and recycled coat- ings: temperatures, pressure, injection parameters, carrier gas flow rate (the deposition time was about 1 h to inject about 160 mL of solution). The only difference was that the precursor concentration of the recycled solution was significantly lower due to consumption during previous runs. As a result, the growth rate in recycling mode was significantly lower. No attempt was made to change the deposition parameters in order to compare the characteristics of the coatings under identical growth conditions. The main CVD conditions are reported in Table 1 .
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Chromium carbide growth at low temperature by a highly efficient DLI-MOCVD process in effluent recycling mode

Chromium carbide growth at low temperature by a highly efficient DLI-MOCVD process in effluent recycling mode

In this paper, “new” coatings refer to coatings elaborated using a freshly prepared liquid solution of as-received precursor and solvent, while “recycled” coatings concern coatings deposited using directly a recycled liquid solution of precursor, by-products and solvent. The same experimental parameters were used for new and recycled coat- ings: temperatures, pressure, injection parameters, carrier gas flow rate (the deposition time was about 1 h to inject about 160 mL of solution). The only difference was that the precursor concentration of the recycled solution was significantly lower due to consumption during previous runs. As a result, the growth rate in recycling mode was significantly lower. No attempt was made to change the deposition parameters in order to compare the characteristics of the coatings under identical growth conditions. The main CVD conditions are reported in Table 1 .
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Characterization of TFETs made using a Low-Temperature process and innovative TFETs architectures for 3D integration

Characterization of TFETs made using a Low-Temperature process and innovative TFETs architectures for 3D integration

Figure 1.3. Power consumption of Intel’s CPUs in history. In early 2000’s the limit of 100 Watts was already reached [7]. Due to a lower switching energy in successive technology generations, each new released microprocessor could operate at higher frequencies and therefore, offered higher computer performance. Unfortunately, device shrinking was accompanied by an increase in IC power density. Figure 1.3 shows that the power consumption has increased from almost 2 W/cm 2 in the i386 processor (1.5 µm gate length) to nearly 100 W/cm 2 in Pentium processors (0.13 µm gate length). At this point it became clear that it would be impossible to simultaneously increase the transistor density and the operation frequency of microprocessors. Finally, the solution adopted was to continue increasing the number of transistors according to Moore’s law, while limiting the microprocessors operating frequency to a few GHz in order to make ICs able to work under practical thermal conditions. However, to solve the limitations of this constraint with respect to the output performance, it was necessary to modify the process architecture from single core to multi-core. With this approach, each core would run up to 2 GHz, while the total output rate of the microprocessor is fold by the output combination of the multiple cores.
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2020 — Suspended carbon nanotube beams fabricated by a low temperature surface micromachined process for humidity and gas sensing

2020 — Suspended carbon nanotube beams fabricated by a low temperature surface micromachined process for humidity and gas sensing

61 The detailed fabrication process has been discussed previously in (Arunachalam et al. 2018). Notably, the fabrication process features a very low temperature budget (i.e. below 110°C) and is amenable to integration above integrated circuits. The following is a brief overview of the fabrication process. The process is carried-out on a Silicon (Si) substrate. SU8, an epoxy based negative photoresist is used as a sacrificial layer to obtain suspended CNTs. SU8 was chosen as the sacrificial material due to its uniform surface profile and ease of availability. The SU8 is partially crosslinked by UV lithography. The Crosslinked SU8, of thickness 3.6 µm, is used as anchors for the CNT beam while the uncrosslinked SU8 is used as a sacrificial layer. The uncrosslinked SU8 is prevented from dissolving in further processing steps by depositing a 60 nm barrier layer of Aluminum by filament evaporation. The CNTs used in this work are obtained pre-functionalized with a carboxylic acid group (-COOH) from Carbon Solutions Inc. and used without any further material processing. 0.125 g of the as-obtained CNTs in powder form were dispersed in a 1 weight percent SDS solution. The as-prepared solution was then ultrasonicated for 6 hours at room temperature resulting in a uniformly dispersed CNT solution. The solution is then ultra-centrifuged at 47300 rpm for 60 minutes. The top half of the solution is then decanted for further use. Then, the CNT films are formed using vacuum filtration. Vacuum filtration enables the formation of a homogenous film with a uniform distribution of CNTs. This process also ensures strict control over film thickness. The CNT films used here are 0.7 µm thick. 20 nm thick aluminum (Al) electrodes are deposited on the CNTs before release to form the suspended CNT beams. The schematic of the resulting suspended CNT beam cross-section is shown in Fig. 5.1(a) and a SEM micrograph of a fabricated beam is shown in Fig. 5.1(b).
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Low-temperature plasma nitriding of martensitic stainless steel

Low-temperature plasma nitriding of martensitic stainless steel

Chromium–molybdenum–vanadium-based tool steels used for wood machining have shown to possess good mechanical properties. However, the wear and corrosion resistance of these steels need to improve for the wide- spread applications. The tool industries demand the enhancement of these properties to prolong the life of tools. Hard and corrosion resistant coating, e.g. by following physical or chemical vapour deposition, on the surface of the steel can solve this problem but the poor adhesion and the delamination of the deposited layer limits its applica- tions [ 1 , 2 ]. In this regard, nitriding has already been proved to be a successful method to improve these prop- erties without the problem of delamination of the deposited layers [ 3 , 4 ]. Conventional ammonia nitriding has prob- lems related to controllability of process parameters and side effects to the environment. Later, plasma nitriding, a versatile eco friendly, economical and more efficient method with good controllability of the process parameters has been recognized. A host of literature supports the enhancement of mechanical and corrosion resistance properties of various steels, Ti/Ti alloys, etc., by following plasma nitriding [ 5 – 31 ]. Plasma nitriding is vacuum-based process, involves the acceleration of nitrogen ions from its plasma source and at the desirable temperatures, heat the substrate. Nitrogen diffuses into the substrate whereupon it forms the nitrides of the substrate material and the solid solution. The details of the nitriding reactor have been presented elsewhere [ 12 , 29 ].
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Pressure promoted low-temperature melting of metal–organic frameworks

Pressure promoted low-temperature melting of metal–organic frameworks

More similarities between MOFs and minerals are apparent in terms of topological structure. Zeolitic imidazolate frameworks (ZIFs), an important subgroup of MOFs 26 , comprise tetrahedral ZnN4 units as their main building blocks. This structural motif, interlinked with imidazolate (Im, C3H3N2 - ) based ligands, forms continuous low- density networks. ZIFs can be directly compared to natural zeolites, which form frameworks of interlinked tetrahedral SiO4 and AlO4 units. Both, ZIFs 27,28 and zeolites 29,30 retain their microporosity even at relatively high T and P. Even higher T and P ultimately induces phase transitions 31–35 and melting 36 . The formation of glasses from such MOF-liquids 37 is of special interest due to their nature as a new class of melt-quenched glass material formed of amorphous SiO2-like continuous random networks 38 . The formation of MOF glasses via solid state conversion or melt- quenching is of great importance due to their inherent MOF-like chemical
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Low Temperature Plasma Nitriding of Low Alloy Steel for the Enhancement of Hardness

Low Temperature Plasma Nitriding of Low Alloy Steel for the Enhancement of Hardness

1. Introduction In recent past, the cutting tool industries were much concerned about the wear and corrosion resistance properties of the tool surface to prolong the service life of the cutting tools. Hard coatings improve the wear and corrosion resistance of cutting tools but the poor adhesion and delamination limit its application [1, 2]. Instead of coating surface with the hard layer, if the surface is alloyed the risk of poor adhesion and delamination can be eliminated. Nitriding of the surface was found to be a successful process for the improvement of these properties. It has also been realized that nitriding followed by the coating improves the adhesion of the coated layer [3, 4]. Conventional nitriding uses ammonia with no controllability of the process to achieve the desired properties or the modification of the microstructure. Plasma nitriding as one of the most industrially accepted and eco friendly plasma based processes which has successfully enhanced these properties of steels with a good controllability of the process parameters which enable the surface microstructure modified to desired properties [5-10].
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Low Temperature Strain Rate Sensitivity of Titanium Alloys

Low Temperature Strain Rate Sensitivity of Titanium Alloys

Material and experimental procedure The Ti-6Al-4V alloy is part of a hot-forged billet, with the chemical composition as given in Table 1, obtained through a three-step thermo-mechanical treatment. The first step consisted of die forging in the α + β temperature domain, just below the β-transus temperature. The last two steps consisted of heat treatments in the α + β domain. These two steps lead to the α precipitates coarsening and to the releasing the internal stresses. The final microstructure obtained is a duplex microstructure with primary α grains and α/β lamellar grains, see Fig. 1a. Both types of grains show an equiaxed shape and are roughly the same size, about 25 µm. In the lamellar grains, 2 µm wide α lamellae are separated by very thin β layers.
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Low-temperature transport in highly boron-doped nanocrystalline diamond

Low-temperature transport in highly boron-doped nanocrystalline diamond

films. The metal-insulator transition is induced by the increasing doping, thereby also controlling the intragran- ular conductance. Low temperature transport measure- ments suggest that metallic nanocrystalline diamond fol- lows dependencies for the conductivity typical for a gran- ular system with metallic/superconducting grains and strong or low intergranular coupling. On the insulat- ing side of the transition, Efros-Shklovskii-like variable range hopping was observed, while on the metallic side a logarithmic temperature dependence of the conductiv- ity was found. The granular structure influences the superconducting properties and the magnetoresistance in highly boron-doped metallic nanocrystalline diamond films. Tuning of the microscopic parameters leads to rich behaviour and similarities to the superconductor- insulator transition are pointed out, explained on the ba- sis of superconducting fluctuations and the importance of granularity.
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Developing new joining materials for low-temperature electronics assembly

Developing new joining materials for low-temperature electronics assembly

atmosphere Figure 5 : Bismuth oxalate decomposition into bismuth (thermal analysis under nitrogen) [1] H. R. Kotadia, “A review: On the development of low melting temperature Pb-free solders,” Microelectron. Reliab., vol. 54, no. 6–7, pp. 1253–1273, 2014.

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A room temperature process for forming highly conductive features

A room temperature process for forming highly conductive features

INTRODUCTION Conductive traces are the most basic elements in printed electronic devices. They are normally printed using silver conductive inks, either nano particles-based or micro particles-based. While the former one can be used to print conductive traces with a resistivity over 3 times of that of bulk silver, the later one is suitable for printing the races with a resistivity over 7 times of that of bulk silver. The nano particle-based silver inks are expensive to produce and are generally used in the area where high conductivity is essential and features are small. A post thermal annealing or solvent drying process at a typical temperature of 120°C or higher is required for treating the printed traces printed to get the optimum performance for all the inks.
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Temperature induced stresses on modified bituminous low-slope roofing systems

Temperature induced stresses on modified bituminous low-slope roofing systems

As shown in Figure 4a, significant membrane ridging occurred across the roof area. These ridges appeared to occur over insulation joints primarily, but due to being a mechanically attached system, the ridges extend beyond insulation joints in some areas. The membrane ridges were spaced at 4 ft intervals (Figure 4b).The thermographic image of the ridge area (Figure 4d) shows heated air within the ridges (Figure 4e). Different temperature variations can also be observed along the runs of insulation indicating uneven thermal value. At the roof perimeter as shown in Figure 4f, heat loss was observed both at the membrane ridges and at roof perimeter. When the membrane was cut at a large ridges as shown in Figure 4g , gaps were found in the in the polyisocyanurate insulation right below the ridge. The gaps between the boards were found to be ½ in. (12mm) and in some cases it was found be closer to 1 in. (25mm) as shown in Figure 4h and 4i. A small amount of drag was also observed on the exposed screw and fastener indicating the friction between the insulation shrinkage and membrane Figure 4j.
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Low-temperature superstructure and charge-ordering effect in η-Na1.286V2O5

Low-temperature superstructure and charge-ordering effect in η-Na1.286V2O5

phase transition resulting in the doubling of the unit cell in the b direction. The diffractometric study confirmed this first result. The superstructure spots were found to have the same half width at half maximum 共HWHM兲 as that for the main Bragg reflections 共1.69, 0.22, and 0.26 nm ⫺1 in the a * , b * , and c * directions, respectively 兲, indicating the stabilization of a long-range order below T c . Figure 2 shows the peak intensity of the (1 3.5 4) and (1 3.5 4) superstructure reflec- tions as a function of temperature. These curves gradually changed during the experiment. At the beginning of the ex- periment, the structural phase transition was observed at T c , as evidenced by the continuous increase of the intensity be- low T c typical of a second-order phase transition. 15 Two days or one week later, a gradual decrease of the low-temperature intensity was observed. A possible origin for this phenom- enon could be an effect of irradiation, although this is rarely observed in inorganic systems in such experimental condi- tions. Another possibility could also be a stress effect since, in our experiment, the sample was fixed with silver dag and hence was not free to move while undergoing its structural phase transition.
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Domain decomposition methods for the diffusion equation with low-regularity solution

Domain decomposition methods for the diffusion equation with low-regularity solution

is of low-regularity. Identical conclusions can be drawn in R =] − 1, 1[ 3 , partitioned into four sub-parallelepipeds with a wirebasket now equal to the edge (0, 0) ×]−1, 1[. As a matter of fact, high contrast between piecewise constant diffusion coefficient often appears in neutronics [7]. The notion of low-regularity solutions is used in section 6 devoted to numerics, where we study the convergence of non-conforming domain decompositions.

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The periodic Schur process and free fermions at finite temperature

The periodic Schur process and free fermions at finite temperature

We revisit the periodic Schur process introduced by Borodin in 2007. Our contribution is threefold. First, we provide a new simpler derivation of its correlation functions via the free fermion formalism. In particular, we shall see that the process becomes determinantal by passing to the grand canonical ensemble, which gives a physical explanation to Borodin’s “shift-mixing” trick. Second, we consider the edge scaling limit in the simplest nontrivial case, corresponding to a deformation of the poissonized Plancherel measure on partitions. We show that the edge behavior is described, in a certain crossover regime different from that for the bulk, by the universal finite-temperature Airy kernel, which was previ- ously encountered by Johansson and Le Doussal et al. in other models, and whose extreme value statistics interpolates between the Tracy–Widom GUE and the Gumbel distributions. We also define and prove convergence for a stationary extension of our model. Finally, we compute the correlation functions for a variant of the periodic Schur process involving strict partitions, Schur’s P and Q functions, and neutral fermions.
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Protective Alumina Coatings by Low Temperature
Metalorganic Chemical Vapour Deposition

Protective Alumina Coatings by Low Temperature Metalorganic Chemical Vapour Deposition

To cite this version : Sovar, Maria-Magdalena and Samélor, D. and Gleizes, Alain and Alphonse, Pierre and Perisanu , S. and Vahlas, Constantin ( 2007) Protective Alumina Coatings by Low Temperature Metalorganic Chemical Vapour Deposition. Advanced Materials Research, vol. 23 . pp. 245-248. ISSN 1022-6680

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