High resolution 3D chemical characterisation of a cadmium telluride solar cell by dynamic SIMS

Impurity elements such as chlorine and sulphur can have significant effects on the electrical performance of cadmium telluride (CdTe) solar cells. Here, the 3D distribution of such elements in a cadmium chloride treated CdTe device has been determined by high resolution dynamic SIMS, a novel technique that has not been applied to thin-film PV cells. It is found that as well as segregating to grain boundaries following treatment, chlorine also segregates to the CdS/CdTe interface. Conversely, sulphur shows a U-shaped diffusion profile. These results have potential implications for the processing thin-film CdTe devices

6-methyl-11a,12-dihydro-6H-quino[3,2-6] [1,4]benzothiazine: An amidine formed under unusual conditions

The crystal structure determination of the title compound, C 16H14N2S, confirms the amidine nature of this reaction product. In N,N′-diphenylamidines both phenyl groups are nearly orthogonal with the N-C(-C)=N grouping, whereas in this constrained amidine the benzene groups are substantially less twisted [C-C-N-C torsion angles = -17.2 (7) and 38.1 (6)°]. The result is a slightly cupped molecule with the ring-fused benzene rings appearing like the extended wings of a butterfly. The S-C distances of 1.807 (4) and 1.760 (5) A° are significantly different, with the shorter distance representing the S-C bond to a benzene ring. © 2003 International Union of Crystallography Printed in Great Britain - all rights reserved

1-[(1,3-Dihydro-2-benzothienyl)acetyl]-1H-Indole S-oxide

The title compound, C18H15NO2S, consists of two heterocycles, namely an indole and a 1,3-dihydro-2- benzothienyl S-oxide moiety, connected by an acetyl bridge. An S - O distance of 1.5007 (15) Å was observed and the two C - S distances differ, with S - CH2 = 1.8217 (16) Àand S - CH= 1.8516 (16) Å

Highly ²⁸Si Enriched Silicon by Localised Focused Ion Beam Implantation

Solid-state spin qubits within silicon crystals at mK temperatures show great promise in the realisation of a fully scalable quantum computation platform. Qubit coherence times are limited in natural silicon owing to coupling to the 29Si isotope which has a non-zero nuclear spin. This work presents a method for the depletion of 29Si in localised volumes of natural silicon wafers by irradiation using a 45 keV 28Si focused ion beam with fluences above 1×1019 ions cm−2. Nanoscale secondary ion mass spectrometry analysis of the irradiated volumes shows residual 29Si concentration down to 2.3 ± 0.7 ppm and with residual C and O comparable to the background concentration in the unimplanted wafer. After annealing, transmission electron microscopy lattice images confirm the solid phase epitaxial re-crystallization of the as-implanted amorphous enriched volume extending over 200 nm in depth

Traditional Fermented Foods: Challenges, Sources, and Health Benefits of Fatty Acids

Traditional fermented foods harbor microbes that transform raw food components, improving their nutritional, shelf life, organoleptic, and health-promoting characteristics. Fermented foods are an important conduit of contact between bioactive components that act like antigens and the human body system. Versatile microbes in traditional fermented foods are associated with many health-promoting end-products, including dietary fatty acids and inherent fermenting microbial cells. Evidence shows that dietary fatty acid components regulate genes in a hormonally dependent manner, either directly via specific binding to nuclear receptors or indirectly by changing regulatory transcription factors. Fatty acids are implicated in anti-inflammatory, anti-obesogenic, immunoregulatory, cardioprotective, etc., activities. Challenges with scaling the production of traditional fermented foods stem from losing effective consortiums of microbial groups and the production of differential end-products. Industrialists scaling the production of traditional fermented foods must overcome safety and consistency challenges. They need to combine processes that lessen the advent of public health issues and introduce omics technologies that identify and maintain effective consortium groups, prune genes that code for toxic products, and inculcate microbes with additional beneficial characteristics. Incorporating omics in production will avail the benefits of traditional fermented foods to a larger population that craves them outside their native areas

Traditional Fermented Foods: Challenges, Sources, and Health Benefits of Fatty Acids

Traditional fermented foods harbor microbes that transform raw food components, improving their nutritional, shelf life, organoleptic, and health-promoting characteristics. Fermented foods are an important conduit of contact between bioactive components that act like antigens and the human body system. Versatile microbes in traditional fermented foods are associated with many health-promoting end-products, including dietary fatty acids and inherent fermenting microbial cells. Evidence shows that dietary fatty acid components regulate genes in a hormonally dependent manner, either directly via specific binding to nuclear receptors or indirectly by changing regulatory transcription factors. Fatty acids are implicated in anti-inflammatory, anti-obesogenic, immunoregulatory, cardioprotective, etc., activities. Challenges with scaling the production of traditional fermented foods stem from losing effective consortiums of microbial groups and the production of differential end-products. Industrialists scaling the production of traditional fermented foods must overcome safety and consistency challenges. They need to combine processes that lessen the advent of public health issues and introduce omics technologies that identify and maintain effective consortium groups, prune genes that code for toxic products, and inculcate microbes with additional beneficial characteristics. Incorporating omics in production will avail the benefits of traditional fermented foods to a larger population that craves them outside their native areas

Sodium Diffuses from Glass Substrates through P1 Lines and Passivates Defects in Perovskite Solar Modules

Most thin film photovoltaic modules are constructed on soda lime glass (SLG) substrates containing alkali oxides, such as Na2O. Na may diffuse from SLG into a module’s active layers through P1 lines, an area between a module’s constituent cells where the substrate-side charge transport layer (CTL) is in direct contact with SLG. Na diffusion from SLG is known to cause several important effects in II-VI and chalcogenide solar modules, but it has not been studied in perovskite solar modules (PSMs). In this work, we use complementary microscopy and spectroscopy techniques to show that Na diffusion occurs in the fabrication process of PSMs. Na diffuses vertically inside P1 lines and then laterally from P1 lines into the active area for up to 360 μm. We propose that this process is driven by the high temperatures the devices are exposed to during CTL and perovskite annealing. The diffused Na preferentially binds with Br, forming Br-poor, I-rich perovskite and a species rich in Na and Br (Na-Br) close to P1 lines. Na-Br passivates defect sites, reducing non-radiative recombination in the perovskite and boosting its luminescence by up to 5x. Na-Br is observed to be stable after 12 weeks of device storage, suggesting long-lasting effects of Na diffusion. Our results point to a potential avenue to increase PSM performance, but also highlights the possibility of unabated Na diffusion throughout a module’s lifetime, especially if accelerated by the electric field and elevated temperatures achievable during device operation.Published versionF.U.K. thanks the Jardine Foundation and Cambridge Trust for a doctoral scholarship. F.D.G. thanks the European Union (EU) Horizon 2020 research and innovation program under grant No. 764047 (ESPResSo). This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No. 823717 - ESTEEM3. J.F.O. acknowledges funding from the Engineering and Physical Sciences Research Council (EPSRC) Nano Doctoral Training Centre (EP/L015978/1). J.F.O., G.K., and R.A.O. acknowledge Attolight and EPSRC (EP/R025193/1) for funding and supporting the SEM-CL system. E.M.T. thanks the EU Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement no. 841265. S.D.S. and E.M.T. acknowledge funding from the EPSRC (EP/R023980/1), the EPSRC Centre for Advanced Materials for Integrated Energy Systems (CAM-IES, EP/P007767/1), and Cambridge Royce facilities grant (EP/P024947/1). S.D.S. acknowledges funding from the Royal Society and Tata Group (UF150033) and from the European Research Council under the EU Horizon 2020 research and innovation program under grant No. 756962 (HYPERION). W.L. and J.L.M.-D. acknowledge support from the EPSRC (EP/L011700/1, EP/N004272/1), the Leverhulme Trust (RPG-2015-017), and the Royal Academy of Engineering Chair in Emerging Technologies (CiET1819_24). We wish to acknowledge the support of the Henry Royce Institute (HRI) for F.U.K. through the Royce PhD Equipment Access Scheme enabling access to the NanoSIMS facility at Manchester. The NanoSIMS was funded by UK Research Partnership Investment Funding (UKRPIF) Manchester RPIF Round 2. This work was supported by the HRI, funded through EPSRC grants EP/R00661X/1, EP/S019367/1, EP/P025021/1, and EP/P025498/1. F.U.K. thanks Dr. Thomas Aarholt (University of Oslo) for providing a function to read CAMECA NanoSIMS data in Python and Prof. Nripan Mathews (Nanyang Technological University) for useful comments and suggestions