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We report the results of an extensive study employing numerous methods to characterize carrier transport within copper indium gallium sulfoselenide (CIGSS) photovoltaic devices, whose absorber layers were fabricated by diverse process methods in multiple laboratories. This collection of samples exhibits a wide variation of morphologies, compositions, and solar power conversion efficiencies. An extensive characterization of transport properties is reported here—including those derived from capacitance–voltage, admittance spectroscopy, deep level transient spectroscopy, time-resolved photoluminescence, Auger emission profiling, Hall effect, and drive level capacitance profiling. Data from each technique were examined for correlation with device performance, and those providing indicators of related properties were compared to determine which techniques and interpretations provide credible values for transport properties. Although these transport properties are not sufficient to predict all aspects of current-voltage characteristics, we have identified specific physical and transport characterization methods that can be combined using a model-based analysis algorithm to provide a quantitative prediction of voltage loss within the absorber. The approach has potential as a tool to optimize and understand device performance irrespective of the specific process used to fabricate the CIGSS absorber layer. Copyright © 2005 John Wiley & Sons, Ltd.

The low-lying singlet states of biphenylene have been studied using ab initio methods. Vertical excitation energies were calculated by multiconfigurational perturbation theory (CASPT2), starting from a complete active space self-consistent field (CASSCF) reference. The geometries of the most important low-lying excited states were individually optimized at the CASSCF level to study the difference between vertical and adiabatic excitations. Extended atomic natural orbital (ANO)-type basis sets were used to calculate state energies. Geometry optimizations were done with smaller ANO-type basis sets. Excitations from the ground state to the 1 1B3g and 1 1B2u excited singlet states lead to pronounced geometry changes which alter the bond alternation pattern. The theoretical results provide a solid basis for the assignment and interpretation of experimental spectra.

Thin-film copper indium diselenide was prepared by selenization of copper indium oxide deposited by spray pyrolysis of an aqueous solution containing copper and indium salts. The degree of reproducibility in thickness, composition and electrical parameters was found to be good. The electrical parameters could be controlled and tuned for photovoltaic applications reproducibly by means of this cost-efficient fabrication technique.

Three-stage co-evaporation of CIGS imposes stringent limits on the parameter space if high-efficient devices are to result. Substrate temperatures during the 1st stage (as well as during the 2nd and 3rd stage), Se partial pressure, and amount of Na supplied are critical for good nucleation, proper In-Ga-selenide precursor phase, and diffusion of Cu into the precursor, as well as diffusion of Ga through the film. In addition, the degree of Cu-rich excursion impacts maximum performance and process tolerance. Enveloping the above is the basic time-temperature profile inextricably linked to the metals delivery rates. Although high-efficiency, three-stage deposited CIGS devices on the RD i.e., substrate temperatures. Finally, one key advantage of a RTR deposition approach (compact equipment) restricts post CIGS Se exposure and cool-down rates to be vastly different than those practiced in the laboratory.

Global Solar Energy, Inc. (GSE) and lower-tier subcontractor ITN Energy Systems, Inc. (ITN) are addressing process tolerance issues in this program. The definition and resolution of process tolerance issues satisfy many of the goals of the Thin Film Photovoltaics Partnerships Program (TFPPP). First, the investigation is likely to identify acceptable ranges for critical deposition parameters. This will have the benefit of providing upper and lower control limits for in-situ process monitoring components, thus increasing average efficiency as well as yield of product. Second, the exploration may uncover insensitivities to some processing procedures, allowing manufacture of modules at increased throughput and decreased cost. The exploration allows a quantitative evaluation of the trade-offs between performance, throughput, and costs. Third, the proposed program also satisfies the TFPPP goal of establishing a wider research and development base for higher-efficiency processing. Four th, the acquisition of data defining sensitivity to processing has important implications for the required accuracy of process sensors and control. Finally, the program helps the photovoltaic community advance toward a better understanding of CIGS growth, a longer-term goal of the TFPPP.

Global Solar Energy, Inc. (GSE) and subcontractor ITN Energy Systems, Inc. (ITN) are addressing process tolerance issues in this program. The definition and resolution of process tolerance issues satisfy many of the goals of the Thin Film Photovoltaics Partnership Program (TFPPP). First, the investigation is likely to identify acceptable ranges for critical deposition parameters. This will have the benefit of providing upper and lower control limits for in-situ process-monitoring components, thus increasing average efficiency, as well as yield of product. Second, the exploration may uncover insensitivities to some processing procedures, allowing manufacture of modules at increased throughput and decreased cost. The exploration allows a quantitative evaluation of the trade-offs between performance, throughput, and costs. Third, the proposed program also satifies the TFPPP goal of establishing a wider research and development base for higher-efficiency processing. Fourth, the acquisition of data defining sensitivity to processing has important implications for the required accuracy of process sensors and control. Finally, the program helps the photovoltaic community advance toward a better understanding of CIGS growth, which is a longer-term goal of the TFPPP.

PRINTS is a compendium of protein motif 'fingerprints'. A fingerprint is defined as a group of motifs excised from conserved regions of a sequence alignment, whose diagnostic power or potency is refined by iterative databasescanning (in this case the OWL composite sequence database). Generally, the motifs do not overlap, but are separated along a sequence, though they may be contiguous in 3D-space. The use of groups of independent, linearly- or spatially-distinct motifs allows protein folds and functionalities to be characterised more flexibly and powerfully than conventional single-component patterns or regular expressions. The current version of the database contains 200 entries (encoding 950 motifs), covering a wide range of globular and membrane proteins, modular polypeptides, and so on. The growth of the databaseis influenced by a number of factors; e.g. the use of multiple motifs; the maximisation of sequence information through iterative database scanning; and the fact that the database searched is a large composite. The information contained within PRINTS is distinct from, but complementary to the consensus expressions stored in the widely-used PROSITE dictionary of patterns.

The spontaneous formation of voids has been observed in Cu(In,Ga)Se2 films deposited by multistage evaporation processes but was not found commonly in single-stage evaporated material. These voids may be isolated in the grains or may occur at the grain boundaries. The voids exhibit strongly faceted geometries with interior surfaces being close-packed {112} planes of the chalcopyrite structure. A model based on the Kirkendal effect [Trans. AIME 171, 130 (1947)] and the interdiffusion and phase reaction in the bilayer process is proposed to explain the observation. The void shape is analyzed and an approximate Wulff construction [Z. Kristallogr. Mineral. 34, 449 (1901)] is used to estimate the relative surface energies of the predominant facets. Certain dislocation cores are also found to be unstable and convert to nanovoids in the presence of sufficient atomic vacancies moving in the lattice.

Hospital isolates of Escherichia coli resistant to tetracycline (TC) were studied to identify mechanisms which regulate TC resistance levels and ability to transfer TC resistance. Antibiotic resistance patterns, resistance levels to TC, and ability to transfer TC resistance were determined for the isolates. Similar data were obtained for the transferable plasmids after transfer to several new host strains of E. coli . Of the 110 isolates, 50% were able to transfer TC resistance by conjugation. There was a nearly linear relationship between the minimum inhibitory concentration (MIC) of TC for the hospital strains and the percentage of strains at a given MIC that could transfer TC resistance. The strains that were simultaneously resistant to tetracycline, streptomycin, and ampicillin had relatively high MICs of TC and high ability to transfer TC resistance. These results and surveys of TC-resistant E. coli by others suggest that TC resistance levels and transmissibility may be influenced by other resistance markers. The isolates which did not transfer TC resistance by conjugation were tested for the presence of TC resistance plasmids by mobilization or by transformation with deoxyribonucleic acid from the isolates. Evidence for plasmid-mediated TC resistance was found in 92 (84%) of the 110 hospital strains.

Combinations of certain antibiotics and normal human serum at concentrations at which there was no killing by the agents when used alone were found to be bactericidal for Escherichia coli K-12 cells. This effect was observed with tetracycline, streptomycin (SM), trimethoprim, and ampicillin, but not with chloramphenicol or nalidixic acid. Synergy between SM and human serum was also observed against four of nine smooth strains of E. coli . A plasmid-bearing strain of E. coli K-12 was also killed by combinations of tetracycline or SM plus serum, even though the plasmid conferred resistance to tetracycline and SM. Evidence is presented that the synergy between antibiotics and serum is due to a complement-mediated effect on the bacterial cells that makes the cells more susceptible to the bactericidal effects of the antibiotics.

The ability of normal rabbit serum to kill Escherichia coli J6-2 was measured. With the concentration of serum adjusted so that approximately 2% of the cells survived after 2 h of incubation, there was no killing of the same strain bearing the F-like plasmid R100. Other F-like plasmids also provided the host strain with resistance to serum bactericidal activity, whereas none of the I-like plasmids used provided the host strain with resistance. When E. coli J6-2 bore both R100 and an I-like plasmid, there was some resistance to serum but less than with R100 alone. The effects of lysozyme on E. coli J6-2, which had been treated with tris(hydroxymethyl)aminomethane and ethylenediaminetetraacetate, were not altered by the presence of R100. The plasmids from 16 clinical E. coli isolates were transferred to J6-2N, a nalidixic acid-resistant mutant of J6-2. Four of the 16 plasmids provided J6-2N with resistance to normal rabbit serum.

Preliminary measurements of magnetic properties of Triassic diabase in southeastern Pennsylvania imply a Triassic geomagnetic pole in central Siberia, at 62°N, 105°E. This pole is virtually identical to that obtained from paleomagnetic studies of rocks of similar age in New Jersey and Arizona. A North American Triassic pole, the mean of six independent determinations, is located at 62°N, 101°E. Dispersion in directions of magnetization, examined to estimate the intensity of Triassic geomagnetic secular variation, is less than half that predicted by Creer (1962) from an analysis of the present field, which may indicate an episode of relative geomagnetic ‘quiet’ during the Late Triassic. These magnetic measurements also define certain linear distributions of site-mean directions of magnetization, probably caused by differential rotations of diabase units about the regional geologic strike. A preliminary tabulation of magnetic properties suggests several correlations with lithology, including the observation that the strongest, but least stable, magnetic moment is associated with the late-stage granophyric diabase facies. The effective average ratio of remanent to induced magnetization for these intrusions probably falls in the range 1.60 to 1.89.

The North American Cordillera has many instances of rotated crustal blocks. The most important processes causing rotation seem to be: 1) Small-block rotations in discrete shear zones, caused by ductile deformation below the seismogenic layer. 2) Small-block rotations caused by distributed shear within zones of oblique subduction. 3) Rotation caused by northward transport along the western edge of North America. 4) Rotation by terrane transport within the Pacific basin. Other processes may be locally important: 5) Oroclinal bending. 6) Rotation during accretion. 7) Rotation during overthrust faulting.