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Polycrystalline thin films of CuIn1−xGaxTe2 have been deposited by flash evaporation on Corning glass 7059 substrates at Ts=200°C. Hall and resistivity measurements have been carried out down to 77 K. These films are p-type and the variation of the resistivity may be linked to defects, disorder of the material or grain boundaries. The PL spectra of these films after annealing in argon atmosphere at Ta=450°C have showed a broad band emission between 0.98 and 1.12 eV in which the main peak appears at 1.05 eV (at 4.2 K). [Copyright &y& Elsevier]

Abstract: Deposition of CuInSe2 thin film on CuGaSe2 thin film (CuInSe2/CuGaSe2) has been prepared by flash evaporation technique on Corning glass substrates heated at T s =250°C and annealed at 450°C in an argon atmosphere. The properties of the resulting films have been examined by scanning electron microscopy (SEM) and X-ray diffraction. The optical measurements have been carried out in the wavelength range 500–3000nm. X-ray diffraction revealed that the film was single-phase with chalcopyrite structure and has a preferred orientation along the (112) plane. The determined lattice parameters were a =5.75Å and c =11.56Å. SEM micrographs revealed grain sizes ranging from 0.03μm to 0.04μm. The thickness of the thin films is around 0.8μm. The absorption coefficient of this film was above 2.25×104 cm−1 and the band gap was found to be 1.14eV. The annealing in Ar did not influence the composition of the layers considerably but improved the crystalline structure quality. [Copyright &y& Elsevier]

Abstract: Thin films of (Cu/In/Se) were fabricated by evaporated elemental layers of Cu, In and Se on Si (100) and on glass substrates at T S =250°C. Films with phase chalcopyrite structure and strong (112) preferred orientation were produced. EDX showed uniform compositional properties of the films over a substrate area of 1cm2. The optical energy band gap of 0.984eV was obtained and photoluminescence measurements have been carried out in as-deposited polycrystalline Cu/In/Se thin films deposited onto (100) oriented Si wafers doped with 1015 cm−3 of boron. The PL spectra of CuInSe2 show emission peaks at 0.87eV ranging from 0.75 to 0.98eV. The broad emission band is ascribed to donor–acceptor pair (DAP) transition. [Copyright &y& Elsevier]

Abstract: Bulk and thin films of CuIn0.75Ga0.25Te2 have been grown using respectively the sealed quartz ampoule and the flash evaporation techniques. X-ray diffraction results showed that the semiconductor has the chalcopyrite structure. The gaps of the materials were determined from optical measurements and found to be 0.99 and 1.14eV, respectively for bulk and annealed films. Photoluminescence data showed a broad emission localised at 1.05eV. [Copyright &y& Elsevier]

Abstract: Using bulk crystals of CuInSe2 (CIS) grown in an evacuated sealed quartz ampoule, diffusion of zinc in the temperature range (550–700°C) was investigated. The computation of the parameters showed a coefficient of diffusion DZn varying from 10-11 to 10-10cm2s-1 and an energy of activation of 0.41eV. The results of optical analysis made on doped CuInSe2 showed that Zn can act as a donor and the energy EA of the acceptor level was found 23meV. [Copyright &y& Elsevier]

Abstract: Bulk crystals of CuInSe2 (CIS) were grown by vacuum fusion technique with specific proportions of Cu, In and Se. The studied samples, cut from the central part of the ingots, were first characterised by scanning electron microscopy, X-ray diffraction and energy dispersive spectroscopy. The conductivity of the crystals was investigated by using a contactless technique based on hyper-frequency microwave. The method consisted in measurements made in a rectangular resonance cavity at 9192 MHz. Conductivity has been also measured by conventional Van der Paw method and the values obtained, varied in the range [3.10−3–7.10−3]Ω−1cm−1, didn''t show significant discrepancies between the two techniques. [Copyright &y& Elsevier]

Comprehensive risk assessment of brownfield sites requires a broad range of knowledge and multi-disciplinary expertise. Whilst the identification of criteria requirements for preliminary risk assessment has received some attention, there appears to be no studies that have specifically examined professional perspectives relating to these requirements. Yet, variations in professional practitioners' assessments may have significant consequences for the assessment of risks, and how the criteria are imparted to stakeholders. This study aims to identify the criteria requirements for preliminary risk assessment, using the pollutant linkage model (Source-Pathway-Receptor), and explores cross-disciplinary professional perspectives related to these requirements. To this end, this study commenced with a systematic review to identify various criteria streams required for the preliminary risk assessment of brownfield sites. Thereafter, a questionnaire survey was design and shared with brownfield site professionals. Quantitative analysis of the survey responses (n = 76) reveals disciplines have markedly different priorities relating to the same hazard. For instance, geophysicists, geochemists, and hydrologists do not raise concerns regarding ground movement that can result from the removal of storage and tanks, whilst the same hazard was considered as having a high importance by other professions (such as geologists and geotechnical engineers). This example, amongst others revealed in the study, underpins potential issues and implications for various stakeholders compiling and/or using preliminary risk assessment criteria. This study clarifies both the key criteria requirements for the preliminary risk assessment of brownfield sites, as well as the importance of recognising how variation in professionals' perceptions plays in the risk assessment process. Although, specialist knowledge is essential for brownfield site investigation, so is the maintaining a broad-based view of other experts coming from different backgrounds, as this renders holistic risk assessment insights., (© 2022. The Author(s).)

Migration to a different culture may affect opportunities for play and social interaction, essential for children's developing cognitive and social skills. We asked Somali migrant women about experiences of childhood (both while growing up themselves, and subsequent observations) in Somalia and the UK. In Somalia, they described a supportive, connected community and safe environment enabling children to play and learn together. In the UK, by contrast, multiple local stressors constrained children's opportunities to play and interact. Understanding and improving neighbourhood geography, as experienced and shaped by parents and children, would seem important for promoting early child development in refugee families., (Copyright © 2019 Elsevier Ltd. All rights reserved.)