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The present work aims at investigating the electronic, optical, photovoltaic and thermoelectric properties of AgBiS 2 compound using the density functional theory (DFT) and the modified Becke-Johnson exchange-correlation potential (mBJ). Both hexagonal Matildite and cubic Schapbachite polymorphs were considered. The hexagonal phase is found to be indirect gap semiconductor with band gap energy of about 1.07 eV and high absorption coefficient of 106 cm−1, whereas the cubic phase were metallic. The analysis of band alignment of Matildite with some binary oxides and sulfides revealed interesting results. The photovoltaic properties of AgBiS 2 confirmed that Matildite phase could achieve a short-circuit current of 22 mA/cm2 and conversion efficiency of 20%. Also, we demonstrated that including photon recycling with a proper solar cell design could improve the conversion efficiency. Moreover, interesting thermoelectric performance has been confirmed. • Detailed ab initio investigation of AgBiS 2 polymorphs is presented. • AgBiS 2 semiconducting phase exhibit interesting electronic and optical properties. • Band alignment at interfaces with binary compounds (oxides and sulfides) is addressed. • High short-circuit current and SLME are achieved for Matildite AgBiS 2. • AgBiS 2 polymorphs exhibit interesting thermoelectric performance. [ABSTRACT FROM AUTHOR]

(Bi2S3) x (γ-MnS) 1-x composite thin films have been deposited onto glass substrates using spray pyrolysis method. The structural and compositional investigations confirmed the co-existence of Bi 2 S 3 and γ-MnS binary compounds in the thin films. The surface morphology indicated that the increase in Bi 2 S 3 concentration influences both the shape and the size of γ-MnS crystallites. The optical analysis via transmittance and reflectance measurements revealed that the band gap energy E g decreased from 3.29 eV to 1.5 eV in terms of Bi 2 S 3 content. The electrical parameters such as resistivity ρ, mobility μ, carrier concentrations and Hall coefficient have been obtained by Hall Effect measurements. It is found than incorporation of Bi 2 S 3 enhances the conductivity, and p-type conduction of γ-MnS could be converted to n-type at x = 0.5. The vibrating sample magnetometer measurement has revealed that (Bi2S3) x (γ-MnS) 1-x composite thin films have a ferromagnetic behavior at room temperature. [ABSTRACT FROM AUTHOR]

Titanium dioxide (TiO 2) thin films are deposited onto glass and silicon <100> substrates by high power impulse magnetron sputtering (HiPIMS) at various substrate positions from the substrate-holder center (x = 0, 10, 20 and 30 mm). The structural analysis conducted through XRD and Raman spectroscopy shows that all the films deposited at lower radial distance (x = 0–20 mm) are identified as pure anatase phase of TiO 2 , while those deposited at 30 mm contain a small trace of rutile phase with anatase phase remaining dominant. AFM analysis reveals homogenous surfaces with low values of roughness (2.6–3.8 nm) and a decrease of grain size with the substrate position. The films exhibit high refractive index and large indirect optical band gaps (3.25–3.38 eV). Finally, UV-blocking and antireflection characteristics are studied. [Display omitted] • TiO 2 thin films are deposited on glass substrates by HiPIMS technique at different radial positions. • Pure anatase TiO 2 is obtained at low distances from the substrate to the holder center. • Good UV-blocking and antireflection effects can be reached from a proper tuning of the sample position. [ABSTRACT FROM AUTHOR]

Abstract: A first principles study of structural, electronic and optical properties of zinc aluminum oxide (ZnAl2O4) by means of the full potential linear augmented plane wave method is presented. The local density approximation is used for the exchange-correlation potential. A direct band gap of 4.19eV, in agreement with experiment (E g =3.9eV), was determined. ZnAl2O4 is transparent in the visible spectral region; the excitonic transition associated with the fundamental band gap is 4.17eV. The refractive index value is 1.74 in the ultraviolet spectral region. [Copyright &y& Elsevier]

• First synthesis of Ag@AgCl nanocomposite thin films by spray pyrolysis technique. • XRD, XPS and Raman characterizations showed that the as-deposited films were subjected to compressive and tensile strains. • Optical characterization showed the performance of Ag@AgCl as antireflecting (AR) layer for silicon solar cell. • The films prepared at 350 °C exhibited localized surface Plasmon resonance (LSPR) peak at 704 nm due to embedded Ag NPs.. • The presence of Ag NPs was demonstrated by the TEM analysis. Silver chloride thin films were easily prepared for the first time by direct spraying of silver chloride (AgCl) solution with low molarity on glass substrates heated at 200 °C, 250 °C, 300 °C and 350 °C. The X-ray diffraction (XRD) data showed that the films have cubic symmetry and are subject to compressive and tensile strains. Transmission electron microscopy revealed the presence of Ag nanoparticles (NPs) of different sizes embedded in AgCl thin films. These nanoparticles were roughly spherical and well crystallized in the case of the film prepared at 350 °C. The Raman and X-ray photoelectron spectroscopy confirmed the XRD results. The UV–vis-NIR spectroscopy indicated a low reflectance with antireflecting properties and high optical transmission superior to 80 % at 350 °C. The obtained films have wide indirect band gap and exhibit localized surface plasmon resonance (LSPR) peak at 407 nm at deposition temperature of 350 °C due to the presence of Ag NPs. [ABSTRACT FROM AUTHOR]