Cadmium-free Thin-Film Cu(In,Ga)Se2(In2S3) Heterophotoelements Fabrication and Properties

The method of heat treatment of metallic Cu–In–Ga layers in the N2 inert atmosphere in the presence of selenium and sulfur vapors was used to grow homogeneous films of Cu(In,Ga)(S,Se)2 alloys onto which the CdS or In2S3 films were deposited and, on the basis of these structures, the thin-film glass/Mo/p-Cu(In,Ga)(S,Se)2/n-(In2S3,CdS)/n-ZnO/Ni–Al photoelements were fabricated. The mechanisms of charge transport and the processes of photosensitivity in the obtained structures subjected to irradiation with natural and linearly polarized light are discussed. The broadband hotosensitivity of thin-film heterophotoelements and the induced photopleochroism were detected; these findings indicate that there is an interference-related blooming of the structures obtained. It is concluded that it is possible to use ecologically safe cadmium-free thin-film heterostructures as high-efficiency photoconverters of solar radiation

Optical Properties of Cu(In, Ga)(S, Se)2 Films for Solar Cells

In this paper, we present structural and optical properties of single-phase Cu(In, Ga)(S, Se)2 alloys, which have been prepared using a novel selenization/sulfurization growth process to react copper-indium-gallium alloy films. The grown scheme differs critically from standard two-step grown processes and was carried out without toxic H2S and H2Se gases. The calculated band gap values for layers with varying sulfur content (i.e. S/(S+Se) = 0.16 and 0.19), determined from optical transmission and reflectance measurements, were found to be 1.17 and 1.23 eV respectively. The low temperature PL measurements also confirmed the shift in the band gap of the CIGSS absorber films with sulfur incorporation. In summary, this reaction process produced single-phase CIGSS thin films with controlled sulfur amount suitable for photovoltaic application

Separated and overlapping neural coding of face and body identity

Recognising a person's identity often relies on face and body information, and is tolerant to changes in low-level visual input (e.g., viewpoint changes). Previous studies have suggested that face identity is disentangled from low-level visual input in the anterior face-responsive regions. It remains unclear which regions disentangle body identity from variations in viewpoint, and whether face and body identity are encoded separately or combined into a coherent person identity representation. We trained participants to recognise three identities, and then recorded their brain activity using fMRI while they viewed face and body images of these three identities from different viewpoints. Participants' task was to respond to either the stimulus identity or viewpoint. We found consistent decoding of body identity across viewpoint in the fusiform body area, right anterior temporal cortex, middle frontal gyrus and right insula. This finding demonstrates a similar function of fusiform and anterior temporal cortex for bodies as has previously been shown for faces, suggesting these regions may play a general role in extracting high-level identity information. Moreover, we could decode identity across fMRI activity evoked by faces and bodies in the early visual cortex, right inferior occipital cortex, right parahippocampal cortex and right superior parietal cortex, revealing a distributed network that encodes person identity abstractly. Lastly, identity decoding was consistently better when participants attended to identity, indicating that attention to identity enhances its neural representation. These results offer new insights into how the brain develops an abstract neural coding of person identity, shared by faces and bodies

Obituary: Leopold Dmitrievich Sulerzhitsky (1929-2012)

The Radiocarbon archives are made available by Radiocarbon and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform February 202

Investigation of defects in Cu(In,Ga)(S,Se)2 films using the photocurrent decay technique

In the present work we demonstrate the possibility of using the photoinduced current transient spectroscopy (PICTS) method to study the defects in Cu(In,Ga)(S,Se)2 films which can be used as an absorber layer in solar cells (SCs). The conducted experiments enable one to determine the parameters (activation energies and effective capture cross-sections) of the defects revealed in the films under study

ZnO based transparent conductive oxide films with controlled type of conduction

The transparent conductive oxide films with controlled type of conduction are of great importance and their preparation is intensively studied. In our work, the preparation of such films based on doped ZnO was realized in order to achieve controlled type of conduction and high concentration of the charge carriers. Sol-gel method was used for films preparation and several dopants were tested (Sn, Li, Ni). Multilayer deposition was performed on several substrates: SiO2/Si wafers, silica-soda-lime and/or silica glasses. The structural and morphological characterization of the obtained films were done by scanning electron microscopy, X-ray diffraction, X-ray fluorescence, X-ray photoelectron spectroscopy and atomic force microscopy respectively, while spectroscopic ellipsometry and transmittance measurements were done for determination of optical properties. The selected samples with the best structural, morphological and optical properties were subjected to electrical measurement (Hall and Seebeck effect). In all studied cases, samples with good adherence and homogeneous morphology as well as monophasic wurtzite type structure were obtained. The optical constants (refractive index and extinction coefficient) were calculated from spectroscopic ellipsometry data using Cauchy model. Films with n- or p-type conduction were obtained depending on the composition, number of deposition and thermal treatment temperature