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Semiconducting CdIn2Se4 thin films have been deposited on to the conducting glass substrates using pulsed electrodeposition technique. X-ray diffraction (XRD) shows the films are polycrystalline in nature having cubic crystal structure. Energy dispersive analysis (EDAX) spectrum of the surface composition confirms the nearly stoichiometric CdIn2S4 nature of the film. Atomic force microscope (AFM) shows that the deposited films are well adherent and grains are uniformly distributed over the surface of substrate. The surface roughness and grain size increased from 0.2 nm and 12 nm to 0.7 nm and 20 nm respectively with increase of duty cycle. The films are highly transparent in the visible region with an average transmittance reaching up to 80%, which indicates the better crystalline nature with less defects. The CdIn2Se4 thin films show band gap energies of the films decreased from 3.12 eV to 3.77 eV. Keywords: Structural studies, XPS, AFM, Optical properties and photosensitivity

X-ray fluorescence, themogravimetric-differential thermal analysis, Fourier Transform Infrared spectroscopy, X-ray diffraction, particle size analysis and Atterberg limits were used to study physico-chemical, mineralogical and thermal properties of two types of clays from four different locations of Tamilnadu, India. The chemical and mineralogical compositions of these clays differ considerably. The mineralogy indicated that the alluvial clays (G1 and G2) comprise highly quartz, illite, kaolinite, plagioclase and small amount of chlorite. The red clays (R1 and R2) were also rich in quartz, well-ordered kaolinite and abundant Fe-bearing minerals such as goethite and hematite. With respect to chemical composition, the G1 and G2 clays contained high amount of SiO2, low amount of Al2O3 and low loss on ignition, however, the R1 and R2 clays contain moderate amount of SiO2, Al2O3, and high amount of Fe2O3 and high loss on ignition. The results indicate that clays from alluvial deposit have adequate characteristics for common brick fabrication. However, clays collected from red clay deposit possessing adequate properties for roofing tile manufacturing and can be used for the manufacturing of common brick with some modification.As técnicas de fluorescência de raios X, análise termogravimétrica-térmica diferencial, espectroscopia no infravermelho com transformada de Fourier, difração de raios X, análise de tamanho de partículas e limites de Atterberg foram utilizadas para o estudo de propriedades físico-químicas, mineralógicas e térmicas de dois tipos de argilas de quatro diferentes localizações em Tamilnadu, India. As composições químicas e mineralógicas dessas argilas diferem consideravelmente. A mineralogia indica que argilas aluviais (G1 and G2) são compostas principalmente de quartzo, ilita, caulinita, plagioclases e pequenas quantidades de cloretos. As argilas vermelhas (R1 and R2) são também ricas em quartzo, caulinita bem ordenada, e minerais abundantes em ferro tais como goetita e hematita. Com relação à composição química, as argilas G1 e G2 contém alto teor de SiO2, baixo teor de Al2O3 e baixa perda ao fogo; as argilas R1 e R2, entretanto, contém teor moderado de SiO2, Al2O3, e alto teor de Fe2O3 e alta perda ao fogo. Os resultados indicam que argilas de depósitos aluviais tem características adequadas para a fabricação de tijolos. Entretanto, as argilas coletadas de depósitos de argilas vermelhas com propriedades adequadas para fabricação de telhas podem ser utilizadas na fabricação de tijolos após algumas modificações.

Sm 3+ ions doped strontium lithium lead borate glasses (SLLB:Sm) were prepared using a conventional melt-quenching technique. The glasses were analyzed using X-ray diffractometry and Fourier transform infrared spectroscopy, optical absorption, fluorescence spectral analysis, and fluorescence lifetime decay. The Judd-Ofelt (J-O) parameters and radiative parameters of the SLLB:Sm10 glass (1.0 mol% Sm 3+ ion-doped glass) were calculated using J-O theory. From the emission spectra, among all the synthesized glass, SLLB:Sm10 glass had the highest emission intensity for 4 G 5/2 → 6 H 11/2 transition (610 nm). Emission parameters, such as stimulated emission cross-section and optical gain bandwidth, were calculated. For all concentrations of Sm 3+ ions, the decay profile showed an exponential nature and decreased when the Sm 3+ ion concentration was increased due to a concentration quenching effect. This result suggests that the synthesized SLLB:Sm10 glass could be used for application in high-density optical memory devices., (© 2020 John Wiley & Sons, Ltd.)

Titanium dioxide (TiO2) thin films had been deposited with various substrate temperatures by spray pyrolysis technique onto ITO substrates. All films exhibited polycrystalline nature with the preferred orientation along (101) plane. At the substrate temperature 450 °C, the film favored the formation of anatase phase. The higher substrate temperature (475 °C) favored the appearance of rutile structure. The SEM image of the film at substrate temperature (Ts=450 °C) showed high structural quality with the porous nature. The typical AFM image of TiO2 film deposited at the substrate temperature, 450 °C depicted the regular arrangement of fine closely packed tetragonal structured grains. The transmittance of the spectra exhibited above 85% with energy band gap of 3.6 eV. From the study of photoluminescence, the emission at 417 nm, 437 nm and with weak emission at 551 nm was observed, which confirmed the lesser defects in the samples. The electrical resistivity was found to be 6.856×10(1) Ω cm for the substrate temperature 450 °C. The efficiency of anatase TiO2 photoelectrode deposited at the substrate temperature 450 °C based cell was much higher than the efficiency of TiO2 photoelectrode deposited at the substrate temperature 475 °C based cell., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Undoped and zirconium doped indium oxide (ZrIO) thin films were deposited on glass substrate at a substrate temperature of 450°C by spray pyrolysis method. The effect of zirconium (Zr) dopant concentration (0-11 at.%) on the structural, morphological, optical and electrical properties of n-type ZrIO films were studied. X-ray diffraction (XRD) results confirmed the polycrystalline nature of the ZrIO thin film with cubic structure. The grain size was decreased from 25 to 15.75 nm with Zr doping. The scanning electron microscopy (SEM) showed that the surface morphology of the films were changed with Zr doping. The surface roughness of the films was investigated by atomic force microscopy (AFM) and was found to be increased with the increasing of Zr doping percentage. A blue shift of the optical band gap was observed. The optical band was gap decreased from 3.50 to 3.0eV with increase in Zr concentrations. Room temperature photoluminescence (PL) measurement of the deposited films indicated the incorporation of Zr in In2O3 lattice. The film had low resistivity of 6.4 × 10(-4)Ωcm and higher carrier concentration of 2.5 × 10(20) was obtained at a doping ratio of 7 at.%., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Tin doped zinc oxide (ZnO:Sn) thin films were deposited onto glass substrates by the spray pyrolysis technique with the substrate temperature 400 °C. The structural, optical, photoluminescence (PL) properties and morphological studies were investigated for the films deposited with various doping concentration (0, 2, 4, 6 and 8 at.%) of tin. The XRD results had shown that the films were polycrystalline ZnO with hexagonal wurtzite type structure and the crystallites in the films were oriented along (002) direction. Surface morphology of the films obtained by scanning electron microscope (SEM) exhibited the change in morphology with doping concentration and porous nature for the film with 6 at.% of tin. Atomic force microscopy (AFM) revealed nanometer sized particles with decreased surface roughness for Sn doping. Optical analysis exhibited the band gap value of 2.8 eV for ZnO:Sn (6 at.%) which was lower than the band gap value for undoped ZnO film (3.2 eV). The resistivity of 6 at.% of Sn doped film was 1.28×10(2) Ω cm with increase in the hall mobility and carrier concentration. The ZnO and Sn doped ZnO thin films exhibited antibacterial activity against Staphylococcus aureus., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Zinc doped Titanium dioxide (TiO2: Zn) thin films were deposited onto glass substrates by the spray pyrolysis technique with the substrate temperature 450°C. The structural, optical, photoluminescence (PL) properties and morphological studies were investigated for the films deposited with various doping concentration (0, 2, 4, 6 and 8at.%) of zinc. The results of X-ray diffraction (XRD) had shown the presence of anatase peak with a strong orientation along (101) plane at 8at.% of Zn-doped TiO2 film. Scanning electron microscopy (SEM) study showed the uniform distribution of grains with porous nature. Atomic force microscopy (AFM) observations indicated the tetragonal shape at 8at.% of Zn-doped TiO2 with the particle size and decrease in surface roughness. The emission at 398nm was observed at the 8at.% of Zn-doped TiO2 thin film. The carrier concentration and Hall mobility was increased with doping. The antibacterial activity was highly yielded for the Zn-doped TiO2 thin films., (Copyright © 2014 Elsevier B.V. All rights reserved.)

ZnO thin films had been successfully prepared by spray pyrolysis (SP) technique on ITO/Glass substrates at different substrate temperature in the range 250-400°C using Zinc acetylacetonate as precursor. The X-ray diffraction studies confirmed the hexagonal wurtzite structure with preferred orientation along (002) plane at substrate temperature 350°C and the crystallite size was found to vary from 18 to 47nm. The morphology of the films revealed the porous nature with the roughness value of 8-13nm. The transmittance value was found to vary from 60% to 85% in the visible region depending upon the substrate temperature and the band gap value for the film deposited at 350°C was 3.2eV. The obtained results revealed that the structures and properties of the films were greatly affected by substrate temperature. The near band edge emission observed at 398nm in PL spectra showed better crystallinity. The measured electrical resistivity for ZnO film was ∼3.5×10(-4)Ωcm at the optimized temperature 350°C and was of n-type semiconductor. The obtained porous nature with increased surface roughness of the film and good light absorbing nature of the dye paved way for implementation of quality ZnO in DSSCs fabrication. DSSC were assembled using the prepared ZnO film on ITO coated glass substrate as photoanode and its photocurrent - voltage performance was investigated., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Pure and In-doped ZnO thin films were deposited onto glass substrates by spray pyrolysis technique. XRD results showed that all films were polycrystalline in nature with the wurzite structure. A change in preferential orientation from (002) to (101) plane was observed with increase in content of Indium. A reduce in crystallite size was observed with increase of In content. The small sized grains with the porous nature of the film was observed from SEM analysis. AFM study depicted polycrystalline nature and uniformly distributed grains with small pores in the doped film. A decrease in band gap was noticed with increase in In content. The absence of green emission in PL spectra indicated the decreased oxygen defects. The decrease in the resistivity with increase of Hall mobility was noted for the doped film. A better antibacterial activity was observed against Staphylococcus aureus by doped ZnO thin film., (Copyright © 2015. Published by Elsevier B.V.)

Nanometer sized SnS2 particles were synthesised by solid state reaction between tin chloride and thiourea in air at 150-350°C. The structural, morphological and optical properties were characterized by using X-ray diffraction (XRD), FT-IR, FT-Raman, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), field emission scanning electron microscopy (FE-SEM), photoluminescence (PL) and UV-Vis spectra. The X-ray diffraction (XRD) pattern of the product was indexed to the hexagonal phase of SnS2. Crystallite size, microstrain and dislocation density were evaluated from the XRD data. EDS analysis indicated that the elemental ratio was similar to tin disulphide (SnS2). The blue shift in the absorption edge was observed from the UV-Vis spectrum. The photoluminescence spectra showed two emission peaks corresponding to blue and red emission., (Copyright © 2014 Elsevier B.V. All rights reserved.)

In this work, highly transparent conducting un-doped and Zn-doped In2O3 thin films were prepared onto glass substrate using spray pyrolysis method. Structural, morphological, optical and electrical properties were characterized by using XRD, FT-IR, FT-Raman, SEM, AFM, UV-visible, PL and Hall Effect measurement techniques. X-ray diffraction analysis showed that the deposited films were polycrystalline with cubic structure having (222) as preferred orientation. SEM and AFM analyses showed smooth surfaces but the surface roughness of the films increased due to Zn doping. The average optical transmittance of the films was above 94% in the visible range. The optical band gap decreased from 3.62 to 3.28 eV with increasing Zn concentration. The photoluminescence spectra displayed violet-blue emission peaks at around 418-440 nm for all films. The electrical parameters like the resistivity, mobility and carrier concentration were found as 6.4×10(-4) Ω cm, 168 cm(2)/Vs and 9.4×10(20) cm(-3), respectively for In2O3:Zn film deposited at 9 at.%. The present results showed that the obtained thin films could be used as an optoelectronic material., (Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.)

Zinc oxide films were doped with different concentrations of Ti on glass substrates at 400°C by spray pyrolysis technique. The films exhibited single phase ZnO for low concentrations of Ti. Wurtzite ZnO peaks were observed at higher doping concentration with decreased crystallinity. Crystallite size, strain and dislocation density were evaluated from the X-ray diffraction data. Surface morphology of the films indicated that a remarkable decrease in grain size with increasing of Ti concentration. The band gap of the films was found to be increased from 3.20 eV to 3.32 eV as the concentration of Ti doping increases. The resistivity of the films decreased from 9×10(5) Ω cm to 9×10(4) Ω cm with the increase of Ti doping concentration. Both Raman spectroscopy and room temperature photoluminescence exhibited characteristic peaks that confirmed the formation of ZnO phase., (Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.)

Thin films of antimony doped tin sulphide (SnS:Sb) with different antimony concentrations have been prepared by the spray pyrolysis technique at the substrate temperature of 350°C. The physical properties of the films were studied as a function of increase in antimony dopant concentration (up to 10at.%). The films were characterized by different techniques to study their structural, optical and electrical properties. The X-ray diffraction analysis revealed that the films were polycrystalline in nature and having orthorhombic crystal structure with a preferred orientation in (111) direction. Due to Sb doping, the crystalline quality and the preferential orientation of SnS films were improved up to 6at.% of doping concentration. However, when doping concentration was increased above 6at.%, the crystalline quality and the preferential orientation of SnS films was deteriorated. Atomic force microscopy images revealed that the surface roughness of the films increased due to Sb doping. Optical measurements showed that the band gap values decreased from 1.60eV to 1.15eV with increase in Sb concentration. The photoluminescence spectra displayed that all the samples have an emission peak centered at 760nm. At 6at.% of Sb doping, the film has the lowest resistivity of 2.598×10(-2)Ωcm while the carrier concentration was high., (Copyright © 2013 Elsevier B.V. All rights reserved.)