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In this work, we reported TEM observations of several CdS thin films prepared by close space submission, sputtering, chemical bath deposition and electronic deposition technologies. The CdS layers prepared by close space submission and sputtering methods had larger grains (50–80 nm), while the CdS layers deposited by chemical bath had very small grains with the size of 5–10 nm. Electro deposited CdS yielded more like an epitaxial film. The optical and chemical properties showed good quality of CdS films prepared by all methods. In this work we proposed a suitable CdS multilayer structure to use it as a window layer in thin film solar cells. [ABSTRACT FROM AUTHOR]

In this work, copper indium gallium selenide (CIGS) thin films were prepared by sputtering CIGS quaternary target and subsequent annealing in the 450–550 °C range. For analyses purpose, the films were peeled off from Mo-coated glass and both parts were named as ‘CIGS side’ and ‘Mo side’ respectively. Raman spectroscopy and X-Ray Photoelectron Spectroscopy (XPS) were performed to identify crystalline phases and chemical compositions. On the ‘Mo side’, a MoSe x layer was evidenced with increased thickness for higher annealing temperature. On the ‘CIGS side’, XPS highlighted a continuous Ga enrichment and a Cu content decrease with increasing temperature. Na was detected on both Mo and CIGS sides. Its concentration and distribution relied on the temperature. Finally, relationships between interface modifications and annealing temperature were discussed . [ABSTRACT FROM AUTHOR]

Graphical abstract Highlight • Wide photoresponse in the visible to near infrared wavelength. • High optical absorption coefficient. • New materials used in the field of infrared detector. Abstract In this work, we prepared BiCuSeO polycrystalline films by evaporating precursors following with selenization treatment. Their optical and photoelectrical properties were investigated from visible to infrared light. Optical absorption spectrum indicated that the absorption coefficient was 104–105 cm−1 from 0.4 μm to 2 μm. Photo induced voltages were clearly detected when the film surfaces were irradiated by the lasers with various wavelengths and powers. The voltage had a linear dependence with the laser illumination intensity, which indicated the main response mechanism of photo-thermal electric effect in the films. All the results suggested that the BiCuSeO film was a potential material for near infrared detector application. [ABSTRACT FROM AUTHOR]

• Novel C 2 N based electrode for Hydrogen Evolution Reaction (HER). • C 2 N based electrode has an excellent stability for HER. • Pt coated C 2 N shows a Tafel slope of 53 mV/dec and an overpotential 33 mV. In this work, a novel catalyst based on holey nitrogenated graphene (C 2 N) was developed for hydrogen evolution reaction (HER). C 2 N nanosheets were deposited on Fluorine doped Tin Oxide substrate by using a facile drop-coating method. Electrochemical tests indicated that C 2 N based work electrode exhibited excellent stability in acidic environment. To improve its catalytic performance, various noble-metal nanoparticles were deposited on the surface of C 2 N using physical vapor deposition, including Au, Cu, Co, Ni and Pt. The size most particles was observed to be 3–5 nm, which was beneficial for catalyst reaction. Among those samples with different metal particles, Pt coated C 2 N multi-catalysts exhibited an overpotential of 33 mV and Tafel slope of 53 mV/dec, which outperformed other metal particles, and also pure Pt particles or C 2 N nanosheets without metallic particles, demonstrating its great potential of multi-catalyst Pt/C 2 N for HER application. [ABSTRACT FROM AUTHOR]

In this work, copper indium gallium selenide (CIGS) absorbers were prepared by sputtering a CIGS quaternary target followed by a subsequent annealing process. The electronic properties and microstructure of the CIGS films with various annealing time were investigated. The various annealing time changes the content of the Cu–Se compounds. A high Cu–Se content leads to a high carrier concentration and a low mobility. An improved efficiency of the solar cell device was found to be highly correlated with the decrease of the Cu–Se content. By decreasing the Cu–Se content, a device with a highest efficiency of 8.63% was achieved in this work. [ABSTRACT FROM AUTHOR]