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Digesta were collected from the intestines of seven species of bottom‐feeding fish to better understand the role of incidental ingestion of sediment in exposing fish to inorganic contaminants. A composite sediment tracer variable, based on concentrations of Co, Cr, Ni, Ti, V, and Y in digesta and in sediment, was calculated to estimate sediment content of digesta. Concentration factors (mg/kg in digesta divided by mg/kg in sediment) of eight elements of interest were linearly regressed on this tracer variable. The relative importance of sediment ingestion to oral exposure was quantified. Zinc, Cd, and Cu were ingested mainly from sediment‐free food. Arsenic, Cr, Ni, Al, and Pb, in contrast, were ingested mainly from sediment. As an example, 93% of the Ni in digesta from a brown bullhead (Ameiurus nebulosus) was from sediment and only 7% from food. Regressions of Al and Pb in digesta of suckers (Catostomidae) suggested an additional oral source, possibly from oxides coating biotic or abiotic surfaces. Overall, concentrations of 12 of 21 elements studied were positively correlated with sediment content (p < 0.005). Including sediment ingestion as a pathway for bottom‐feeding fish is essential for accurately estimating exposures in toxicological studies. Environ Toxicol Chem 2024;43:1036–1046. Published 2024. This article is a U.S. Government work and is in the public domain in the USA. [ABSTRACT FROM AUTHOR]

Surface passivation is essential for high-efficiency crystalline silicon (c-Si) solar cells. Despite the common use of transparent conductive oxides (TCOs) in the field of solar cells, obtaining surface passivation by TCOs has thus far proven to be particularly challenging. In this work, we demonstrate outstanding passivation of c-Si surfaces by highly transparent conductive ZnO films prepared by atomic layer deposition. Effective surface recombination velocities as low as 4.8 cm/s and 11 cm/s are obtained on 3 Ω cm n- and p-type (100) c-Si, respectively. The high levels of surface passivation are achieved by a novel approach by using (i) an ultrathin SiO2 interface layer between ZnO and c-Si, (ii) a sacrificial Al2O3 capping layer on top of the ZnO film during forming gas annealing, and (iii) the extrinsic doping of the ZnO film by Al, B, or H. A combination of isotope labeling, secondary-ion mass spectrometry, and thermal effusion measurements showed that the sacrificial Al2O3 capping layer prevents the effusion of hydrogen from the crystalline ZnO and the underlying Si/SiO2 interface during annealing, which is critical in achieving surface passivation. After annealing, the Al2O3 capping layer can be removed from the ZnO film without impairing the high levels of surface passivation. The surface passivation levels increase with increased doping levels in ZnO, which can be attributed to field-effect passivation by a reduction in the surface hole concentration. The ZnO films of this work are suitable as a transparent conductor, an anti-reflection coating, and a surface passivation layer, which makes them particularly promising for simplifications in future solar cell manufacturing. [ABSTRACT FROM AUTHOR]

The influence of implanted hydrogen (up to a concentration level of 3 at. %) on the microstructure of silicon (Si) materials is investigated by Fourier transform infrared spectroscopy as well as by effusion of hydrogen and of (low dose) implanted helium. Three materials of low original hydrogen concentration, crystalline Si, electron beam evaporated amorphous Si, and plasma-deposited hydrogenated amorphous Si (using high deposition temperature) were investigated. Significant differences between crystalline and amorphous materials were observed. In crystalline Si, implanted hydrogen is found to generate multivacancies that trap diffusing helium while this is not the case in amorphous Si. Accordingly, cavities where hydrogen is located in amorphous Si must be smaller than divacancies. Those cavities in amorphous Si, present from the growth process, that trap helium tend to disappear when the implanted hydrogen concentration increases. Annealing of the materials up to temperatures of 575°C was also studied. No significant change in the density of voids (trapping helium) occur but in case of crystalline Si the bonding sites of hydrogen as well as the diffusion paths of helium change. PACS Nos.: 61.43.Dq, 61.72.uf, 81.40.-z. Nous utilisons la spectroscopie infrarouge a transformee de Fourier, l'effusion d'hydrogene (H) et l'implantation d'helium (He; a basse dose), pour etudier l'influence de l'implantation d'H (jusqu'a des concentration de 3 at. %) sur les microstructures de materiaux de silicium. Nous etudions trois de ces materiaux de faible concentration initiale en H, le silicium cristallin, le silicium amorphe evapore par faisceau electronique et le silicium amorphe hydrogene par depot (a haute temperature). Des differences importantes apparaissent entre materiaux cristallins et amorphes. Dans le silicium cristallin, l'H implante cree des multi-lacunes qui piegent l'He en diffusion, ce qui n'est pas le cas pour le silicium amorphe. Consequemment, les cavites ou se trouve l'H dans le Si amorphe doivent etre plus petites que des bi- lacunes. Ces cavites qui piegent l'He dans le silicium amorphe, presentes lors de l'elaboration du materiau, tendent a disparaitre lorsque la concentration de l'H implante augmente. Nous etudions aussi l'effet d'un recuit des materiaux jusqu'il 575°C. Aucun changement significatif de la densite de pieges n'apparait, mais dans le cas cristallin, les sites de capture de H et les trajectoires de diffusion de He changent. [Traduit par la Redaction], 1. Introduction Void-related microstructure is an important issue in hydrogenated amorphous silicon (a-Si:H) technology as it may limit the performance and the lifetime of a-Si:H based devices. The relation between [...]