Sputtered nickel oxide thin film for efficient hole transport layer in polymer–fullerene bulk-heterojunction organic solar cell
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bio-inspired↗
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Pervasive liquid metal based direct writing electronics with roller-ball pen
A roller-ball pen enabled direct writing electronics via room temperature liquid metal ink was proposed. With the rolling to print mechanism, the metallic inks were smoothly written on flexible polymer substrate to form conductive tracks and electronic devices. The contact angle analyzer and scanning electron microscope were implemented to disclose several unique inner properties of the obtained electronics. An ever high writing resolution with line width and thickness as 200 μm and 80 μm, respectively was realized. Further, with the administration of external writing pressure, GaIn{sub 24.5} droplets embody increasing wettability on polymer which demonstrates the pervasive adaptability of the roller-ball pen electronics.
36 MATERIALS SCIENCE↗
PEM Electrode Assembly Manufacturing and Automated Stack Assembly US Operation (CRADA Final Report)
NLR will perform experiments and simulations to validate catalyst layer coating processes. Catalyst inks will be formulated to tune rheology, surface tension, and other ink properties to achieve uniform coatings and appropriate thicknesses.
08 HYDROGEN↗
Laser sintering of a TiO{sub 2} nanoporous film on a flexible substrate for application in solar cells
The selective laser sintering of TiO{sub 2}-film nanoparticles on a plastic conductive substrate is considered for application in flexible dye-sensitized solar cells. It is shown that the absorbed energy of the laser radiation during laser sintering promotes electrical-contact formation between TiO{sub 2} nanoparticles without damaging the plastic conductive substrate. The choice of a near-infrared laser radiation (wavelength of 1064 nm) provides an efficient laser-sintering process. The laser-sintering method promotes a decrease in recombination losses in the TiO{sub 2} film and an improvement in the charge-collection efficiency, which can result in an increase in the efficiency of such solar cells. Furthermore, the efficient-laser sintering method has a great potential for application in the roll-to-roll technology of the fabrication of high-efficiency flexible solar cells.
36 MATERIALS SCIENCE↗
Carbon nanotube coated metal mesh: Bridging nanoscale and macroscale
A novel hybrid structure has been developed by growing carbon nanotubes (CNTs) on a metal mesh that functions as a literally unlimitedly extendable backbone. This hybrid material structure provides a new approach of extending CNTs’ advantageous properties such as ultrahigh thermal and electrical conductivities, high sensitivity to gases, and distinctive wettability for different liquids with chemical inertness to macroscale—otherwise available only in nano- and microscales. In this feasibility work, CNTs were grown on a Type 316 stainless steel (SS) mesh by self-catalytical chemical vapor deposition (CVD) without the need of an externally added catalyst or catalyst support. For the radially aligned and entangled CNT forest on the SS mesh, the average CNT diameter is around 50 nm, while the length varies from 20 to 25 µm. High-resolution transmission electron microscopy analysis revealed the multiwall structure of the CNTs with >30 rolled-up graphitic sheets. Raman spectra of the CNTs showed a dominant G band, indicating a well-ordered graphitic nanostructure. Being highly hydrophobic with a water contact angle of ∼145° and oleophilic, the CNT-coated SS mesh could be used in fluid separation and organic contaminant removal from water. Moreover, CNTs are recognized for their exceptional thermal conductivity and the CNT-coated mesh offers a supportive structure with directly connected CNTs for efficient heat transfer. Proof of concept has been achieved for the CNT-coated mesh’s potentials as a liquid filter and an thermal interface material (TIM). Specifically, the CNT-coated mesh demonstrated the capability of capturing water from a water-organic mixture with a 100 % efficiency while allowing organic liquids to pass through the filter. Furthermore, when used as a TIM, the CNT-coated mesh reduced the interfacial thermal impedance by >30 %.
Carbon nanotubes (CNTS)↗
Method for mask-free OLED deposition and manufacture
A method for making an OLED lighting panel is disclosed. A patterned inorganic insulating layer is used to enclose an area over a first electrode layer leaving portions of the first electrode layer and substrate adjacent to the outside of the enclosure exposed. After uniform deposition of the organic layer(s), the organic layer(s) are selectively removed over the inorganic insulating layer and an adjacent portion of the substrate to form a sealing region. After uniform deposition of the second electrode, the enclosed area is encapsulated and any overlying layers over the first and second electrodes outside the enclosed area are removed resulting in an OLED within the enclosed area with electrode contact pads outside the enclosed area. The OLED can be manufactured at low cost with no or limited use of shadow masking and is suitable for roll-to-roll processes.
Hamer, John↗
DMS Update Manager
The DMS Update Manager is used to keep automated processing manager software up-to-date. Although it is part of PRISM (the Proteomics Research Information and Management System), it is a standalone program and does not contact any databases. The program compares the files on a central distribution share to files on the local computer, updating any files that are out of date. It supports rolling back local files to an older version and auto-deleting extra files.
Monroe, Matthew↗
Fabrication of Ag-Fe{sub 3}O{sub 4}/Fe superhydrophobic surface on galvanic sheet for its application
Highlights: • Ag-Fe{sub 3}O{sub 4}/Fe superhydrophobic surface (SHS) was fabricated on galvanic sheet. • The SHS has water contact angle of 165° and sliding angle of 2°. • The SHS has excellent properties of anti-icing, self-cleaning and catalysis. • This is an easy and cheap method to fabricate SHS on the galvanic sheet. - Abstract: Durable Ag-Fe{sub 3}O{sub 4}/Fe superhydrophobic surface (SHS) with dendritic structures on the galvanic sheet was obtained by chemical etching, deposition and following annealing process. The promising SHS showed fine superhydrophobicity having the water contact angle of 165° and dynamic sliding angle of 2°. Experimental results showed that the obtained SHS sample has excellent properties of anti-corrosion, catalysis, anti-icing, rolling-off and self-cleaning. The conditions of etching, chemical immersion, and annealing to obtain SHS were investigated. Chemical stability and durability of SHS were investigated via storage in air for ten months. The SHS as a catalyst showed long-term stability, catalytic activity, and reusability, as compared to the substrate of the un-annealed surface. It is an effortless and cheap method to fabricate SHS on the galvanic sheet for industrial applications. The SHS has a potential utilization in a diverse range of bio-medicines, chemistry, microfluidics fields, and electronics.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Cyclic steady states of treaded rolling bodies
The analysis of spinning axisymmetric bodies undergoing finite deformation is useful for understanding the behavior of a wide variety of engineering systems - for example, rolling tires. Furthermore, progress beyond the axisymmetric case has been lacking. In this work, we present a methodology for the treatment of treaded rolling bodies by devising a Newton-Krylov shooting scheme for the computation of cyclic steady states of motion. The scheme advocated permits one to determine the entire transient (cyclically steady) motion of a spinning treaded body with consideration of viscoelasticity as well as contact. We demonstrate the viability of the method through three examples, (1) a viscoelastic cylinder with eight sinusoidal tread blocks, (2) a viscoelastic cylinder with 16 square tread blocks, and (3) a viscoelastic oval in which repeated contact and separation from a rigid plane excites distinct transient vibrational modes in the body during each cycle. For practical values of the viscoelastic relaxation time, the new approach is found to converge faster than the naïve approach of evolving an initial guess over many cycles until a cyclic steady state is reached.
42 ENGINEERING↗
Structural Insights into the Functional Role of the Hcn Sub-domain of the Receptor-Binding Domain of the Botulinum Neurotoxin Mosaic Serotype C/D
Botulinum neurotoxin (BoNT), the causative agent of the deadly neuroparalytic disease botulism, is the most poisonous protein known for humans. Produced by different strains of the anaerobic bacterium Clostridium botulinum, BoNT effects cellular intoxication via a multistep mechanism executed by the three modules of the activated protein. Endocytosis, the first step of cellular intoxication, is triggered by the ~50 kDa, heavy-chain receptor-binding module (HCR) that is specific for a ganglioside and a protein receptor on neuronal cell surfaces. This dual receptor recognition mechanism between BoNT and the host cell’s membrane is well documented and occurs via specific intermolecular interactions with the C-terminal sub-domain, Hcc, of BoNT-HCR. The N-terminal sub-domain of BoNT-HCR, Hcn, comprises ~50% of BoNT-HCR and adopts a B-sheet jelly roll fold. While suspected in assisting cell surface recognition, no unambiguous function for the Hcn sub-domain in BoNT has been indentified. To obtain insights into the potential function of the Hcn sub-domain in BoNT, the first crystal structure of a BoNT with an organic ligand bound to the Hcn sub-domain has been obtained. Here, we describe the crystal structure of BoNT/CD-HCR determined at 1.70 Å resolution with a tetraethylene glycol (PG4) molecule bound in an hydrophobic cleft between B-strands in the B-sheet jelly fold roll of the Hcn sub-domain. The molecule is completely engulfed in the cleft, making numerous hydrophobic (Y932, S959, W966, and D1042) and hydrophilic (S935, W977, L979, N1013, and I1066) contacts with the protein’s side chain and backbone that may mimic in vivo interactions with the phospholipid membranes on neuronal cell surfaces. A sulfate ion was also observed bound to residues T1176, D1177, K1196, and R1243 in the Hcc sub-domain of BoNT/CD-HCR. In the crystal structure of a similar protein, BoNT/D-HCR, a sialic acid
botulinum neurotoxin↗
The next generation CdTe technology- Substrate foil based solar cells
The main objective of this project was the development of one of the most promising Photovoltaic (PV) materials CdTe into a versatile, cost effective, and high throughput technology, by demonstrating substrate devices on foil substrates using high throughput fabrication conditions. The typical CdTe cell is of the superstrate configuration where the solar cell is fabricated on a glass superstrate by the sequential deposition of a TCO, n-type heterojunction partner, p-CdTe absorber, and back contact. Large glass modules are heavy and present significant challenges during manufacturing (uniform heating, etc.). If a substrate CdTe cell could be developed (the main goal of this project) a roll-to-toll high throughput technology could be developed.
14 SOLAR ENERGY↗
Impact of K-Optimization on Trap Concentration in (Ag,Cu)(In,Ga)Se 2 Solar Cells
Recent progress has been made in improving efficiency in Cu(In,Ga)Se 2 (CIGS) absorbers with steady increases in peak efficiency. One way this has been achieved is by adding Ag to CIGS (ACIGS) to achieve higher V OC . However, these efficiencies are still well below the Shockley-Queisser efficiency limit, and traps acting as recombination centers and compensating centers are one thing limiting the solar efficiency. Past research in CIGS has shown that alkali treatment can improve the efficiency and metastability problems in CIGS, but less is understood about the role of alkali treatments in ACIGS. Here, we investigate the impact of potassium in ACIGS through its impact on trap incorporation and minority carrier lifetime. The samples in this study were grown in a roll-to-roll coater with Mo, ACIGS, CdS, and ZnO structure. Both cells were grown identically except the second (K-optimized) cell was grown with increased K-doping of the Mo contact and was more Cu-poor near the surface to optimize the K profile. This resulted in an efficiency increase from 16.8% to 18.7% for the K-optimized cell, which was mostly due to a 65 mV V OC increase. The doping profile showed a 2X increase in acceptor concentration of the K-optimized cell (2.5×10 15 cm -3 ) which suggests that the K was better incorporated into the ACIGS after these optimizations. To characterize the traps in these cells, deep level transient and optical spectroscopy were used. The DLOS measurements showed an EV+0.98 eV trap whose concentration was reduced 10X in the K-optimized cell (4×10 14 cm -3 ). This is consistent with previous results from the alkali treatment in CIGS, which also showed a decrease in near-conduction band trap concentration [1], but the reduction was larger than previous studies possibly indicating the combination of K and Cu-poor surface may both have aided in reducing the EV+0.98 eV trap concentration. The other primary trap is the mid-gap trap (EV+0.58 eV), which was quantified using DLTS. Its concentration decreased from 9×10 13 cm -3 to 4×10 13 cm -3 in the K-optimized sample, which is a 2X reduction. Previous studies have shown this trap is likely an efficient recombination center [2], which makes sense because it is near mid-gap. This trap has also been associated with V OC instability and reduction, so reducing this trap concentration is essential to achieve high V OC and cell efficiency. To help confirm this association, time-resolved photoluminescence measurements have shown in this sample set and a previous study that the minority carrier lifetime (19 ns baseline to 56 ns K-optimized) and this EV+0.56 eV trap concentration are inversely proportional, which would be expected for a recombination-limited carrier lifetime. The K optimization of ACIGS results in significantly improved cell efficiency and reduced trap concentrations that correlate with the improved material and electrical properties. We will report on this and the impact of the K optimization on the cell metastability.
14 SOLAR ENERGY↗
Densification Pressure Optimization of MOF-808-Based Membranes for Lithium Metal Batteries
The use of metal–organic frameworks (MOFs) in hybrid electrolytes for lithium (Li) metal batteries has grown in prominence in recent years, primarily due to the chemical tunability of the MOF’s pore structures, which can directly influence Li–ion transport properties. The most attractive form factor for a MOF electrolyte is a thin, flexible membrane, which requires the application of pressure to increase the contact between the MOF particles. Herein, a systematic study of the influence of pressure on the properties of MOF-808-based membranes is presented. It is shown that when a dry, roll-pressed membrane is subjected to pressure ≥120 MPa, a total loss of crystallinity and a significant loss of porosity is observed. Alternatively, a slurry-cast membrane, compressed under controlled pressures, can maintain crystallinity and porosity while decreasing the interparticle void space. Interesting, the conductivity of the membranes infiltrated with liquid electrolyte is not greatly affected by the pressure applied, though ultimately it is shown that for cycling with Li metal, compressed membranes with compact particles are preferred. In conclusion, this study highlights the critical importance of controlling the pressure applied to MOF-based membranes during fabrication and during cell assembly and lays out the foundation for further investigation of how to optimize membrane fabrication for hybrid electrolytes that use MOFs as the dominate component.
25 ENERGY STORAGE↗
The double-soft limit in cosmological correlation functions and graviton exchange effects
The graviton exchange effect on cosmological correlation functions is examined by employing the double-soft limit technique. A new relation among correlation functions that contain the effects due to graviton exchange diagrams in addition to those due to scalar-exchange and scalar-contact-interaction, is derived by using the background field method and independently by the method of Ward identities associated with dilatation symmetry. We compare these three terms, putting small values for the slow-roll parameters and (1− n {sub s} ) ≈ 0.042, where n {sub s} is the scalar spectral index. It is argued that the graviton exchange effects are more dominant than the other two and could be observed in the trispectrum in the double-soft limit. Our observation strengthens the previous work by Seery, Sloth and Vernizzi, in which it has been argued that the graviton exchange dominates in the counter-collinear limit for single field slow-roll inflation.
79 ASTRONOMY AND ASTROPHYSICS↗
Method of manufacturing large dish reflectors for a solar concentrator apparatus
A method of manufacturing monolithic glass reflectors for concentrating sunlight in a solar energy system is disclosed. The method of manufacturing allows large monolithic glass reflectors to be made from float glass in order to realize significant cost savings on the total system cost for a solar energy system. The method of manufacture includes steps of heating a sheet of float glass positioned over a concave mold until the sheet of glass sags and stretches to conform to the shape of the mold. The edges of the dish-shaped glass are rolled for structural stiffening around the periphery. The dish-shaped glass is then silvered to create a dish-shaped mirror that reflects solar radiation to a focus. The surface of the mold that contacts the float glass preferably has a grooved surface profile comprising a plurality of cusps and concave valleys. This grooved profile minimizes the contact area and marring of the specular glass surface, reduces parasitic heat transfer into the mold and increases mold lifetime. The disclosed method of manufacture is capable of high production rates sufficiently fast to accommodate the output of a conventional float glass production line so that monolithic glass reflectors can be produced as quickly as a float glass production can make sheets of float glass to be used in the process.
14 SOLAR ENERGY↗
Nanowire CdS-CdTe solar cells with molybdenum oxide as contact
Using a 10 nm thick molybdenum oxide (MoO 3-x ) layer as a transparent and low barrier contact to p-CdTe, we demonstrate nanowire CdS-CdTe solar cells with a power conversion efficiency of 11% under front side illumination. Annealing the as-deposited MoO 3 film in N2 resulted in a reduction of the cell’s series resistance, from 9.97 Ω/cm 2 to 7.69 Ω/cm 2 , and increase in efficiency from 9.9% to 11%. Under illumination from the back, the MoO 3-x /Au side, the nanowire solar cells yielded Jsc of 21 mA/cm 2 and efficiency of 8.67%. Our results demonstrate use of a thin layer transition metal oxide as a potential way for a transparent back contact to nanowire CdS-CdTe solar cells. As a result, this work has implications toward enabling a novel superstrate structure nanowire CdS-CdTe solar cell on Al foil substrate by a low cost roll-to roll fabrication process.
14 SOLAR ENERGY↗
Air maintenance tire and valve assembly
A self-inflating tire assembly includes an air tube mounted within a tire sidewall groove. The air tube is in contacting engagement with opposite angled groove surfaces surrounding the air tube. A segment of the air tube is flattened from an expanded diameter to a flat diameter by bending and compression of the groove in a rolling tire footprint to force air evacuated from the flattened segment along a tube air passageway. A tube is positioned within the groove, wherein the tube has a circular cross-sectional shape and an outside diameter D, and the groove does not have a circular cross-sectional shape, wherein said groove has a width W and a length L, wherein D is greater than W.
42 ENGINEERING↗
Air maintenance tire
A self-inflating tire assembly includes an air tube mounted within a tire sidewall or chafer groove. The air tube is in contacting engagement with opposite angled groove surfaces surrounding the air tube. A segment of the air tube is flattened from an expanded diameter to a flat diameter by bending and compression of the groove in a rolling tire footprint to force air evacuated from the flattened segment along a tube air passageway. A coverstrip overlays and seals the groove and provides an abrasion resistant surface on the exterior of the tire. The coverstrip is made from a vulcanizable rubber composition comprising from 50 to 80 phr of a polybutadiene, from 50 to 20 phr of natural rubber, and from 0.1 to 5 phr of a vulcanization modifier.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗