Combined in-depth scanning Auger microscopy and Raman scattering characterisation of CuInS2 polycrystalline films
ABSTRACT In this work, the combination of in-depth scanning Auger microscopy with Raman microprobe spectroscopy is applied for the detailed microstructural characterisation of CuInS2 (CIS) thin films. CIS films are used for the fabrication of high efficiency solar cell devices. These films are obtained by sequential sputtering of Cu and In layers on a Mo-coated glass substrate, followed by a sulphurisation step at 500°C in a rapid thermal processing furnace. In order to study this process, samples obtained at intermediate steps are investigated. The obtained data show the formation of the CIS phase already at the first stages of the sulphurisation process, although with a highly disordered structure. Moreover, segregation of CuS towards the surface is observed before sulphurisation is completed. This fact is accompanied by a significant increase of the structural quality of the CIS film, which allows for the fabrication of high efficiency solar cell devices. The performed analysis corroborates the strong complementarity between the used techniques for the detailed microstructural analysis of complex multilayer systems.
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ABSTRACT: This paper describes the detailed microstructral characterisation of S-rich CuIn(S,Se)<sub>2</sub> absorbers fabricated by single step electrodeposition (ED) of nanocrystalline CuInSe<sub>2</sub> precursors followed by rapid thermal annealing under sulphurising conditions. This has allowed identifying the main secondary phases in the precursors as elemental Se, CuSe and Cu<sub>2</sub>Se. The Raman spectra from these precursors also show the presence of Cu-poor OVC domains, which contrasts with the Cu-rich conditions used in the ED growth. This has been related to the presence in the annealed layers of In rich secondary phases, which lead to a slightly Cu poor composition. Moreover, the used sulphurising conditions also lead to the formation of a relatively thick MoS<sub>2</sub> layer between the absorber and the Mo back contact. The high microcrystalline quality of the layers is likely responsible of the relatively high efficiency value of 11% of the solar cells fabricated with these absorbers.Electron Devices, 2007 Spanish Conference on; 01/2007
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ABSTRACT: Didecyldimethylammonium chloride (DDAC) is a Quaternary Ammonium Compound (QAC) disinfectant often used in the poultry industry to disinfect hard surfaces. DDAC is a membrane active agent and causes the leakage of important intracellular material. Understanding the mode of action and possible resistance is important; in particular, the pending post antibiotic era that the poultry industry is facing. Staphylococcus aureus strain ATCC2357 treaded with DDAC revealed protruberances or bleb formations on their cell walls when observed with scanning electron microscopy. The DDAC treated cells were further investigated using NanoSAM. This technology showed morphological changes as well as structural detail on control cells caused by the disinfectant that scanning electron microscopy could not. NanoSAM also showed a decrease in the elemental intensities during the etching of the cells treated with QAC. This proved that QAC leads to the leakage of cellular material.Scientific research and essays 01/2013; 8(3):152-160. · 0.32 Impact Factor