Physical investigations on (In2S3)x(In2O3)y and In2S3-xSex thin films processed through In2S3 annealing in air and selenide atmosphere

In2S3-xSex and (In2S3)x(In2O3)y thin films have been prepared on glass substrates using appropriate heat treatments of In evaporatedt hin films. X-ray analysis shows that In thin films which were annealed under sulfur atmosphere at 350°C were mainly formed by In2S3. A heat treatment o fthis binary in air at 400°C during one hour leads to (In2S3)x(In2O3)y ternary material which has a tetragonal structure with a preferred orientation of the crystallites along the (109) direction. Similarly, a heat treatment of In2S3 in selenium atmosphere at 350°C during six hours leads to a new In2S3-xSex ternary material having tetragonal body centered structure with a preferred orientation of the crystallites along the (109) direction.Optical band gap,refractive index and extinction coefficient values of In2S3-xSex and (In2S3)x(In2O3)y thin films have been reached. Moreover, correlations between optical conductivity, XRD, AFM and Urbach energy of such ternary thin films have been discussed. Finally, the recorded formation disparity between the quaternary (In2S3)x(In2O3)y and ternary In2S3-xSex compounds has been discussed in terms of the Simha–Somcynsky and Lattice Compatibility theories

Boubakerova shema razvoja po polinomima (BPES) i optička svojstva prskanih slojeva β-SnS2

β-SnS2 layers have been prepared on glass substrates by spray pyrolysis technique at temperature Ts ≈ 270◦C. The transmission-reflectance spectra, subjected to an original BPES-related protocol, led to accurate calculations of the effective absorptivity. The knowledge of lastly obtained values of the thermal diffusivity allowed the determination of the opto-thermal expansivity ψAB as a guide to evaluating the conjoint optical and thermal performances of the as-grown layers.Na staklenoj podlozi priredili smo slojeve β-SnS2 metodom vrućeg prskanja na temperaturi 270◦C. Spektri prolazne i odrazne svjetlosti, izvedeni primjenom nove sheme razvoja po Boubakerovim polinomima, omogućili su točno određivanje efektivne apsorptivnosti. Konačno dobiveni podaci za termalnu difuzivnost omogućili su određivanje opto-termičkog širenja ψAB kao vodilju za određivanje povezanih optičkih i termičkih svojstava svježe pripremljenih slojeva

Annealing effect on physical properties of evaporated molybdenum oxide thin films for ethanol sensing

This paper deals with some physical investigations on molybdenum oxide thin films growing on glass substrates by the thermal evaporation method. These films have been subjected to an annealing process under vacuum, air and oxygen at various temperatures 673, 723 and 773 K. First, the physical properties of these layers were analyzed by means of X-ray diffraction, Raman spectroscopy, scanning electron microscopy (SEM) and optical measurements. These techniques have been used to investigate the oxygen index in MoOx properties during the heat treatment. Second, from the reflectance and transmittance optical measurements, it was found that the direct band gap energy value increased from 3.16 to 3.90 eV. Finally, the heat treatments reveal that the oxygen index varies in such molybdenum oxides showing noticeably sensitivity toward ethanol gas

Structural and Optothermal Properties of Iron Ditelluride Layered Structures in the Framework of the Lattice Compatibility Theory

This study concerns structural and optothermal properties of iron ditelluride layered structures which were fabricated via a low-cost protocol. The main precursors were FeCl3 · 6H2O and Fe2O3. After a heat treatment within a tellurium-rich medium at various temperatures (470°C, 500°C, and 530°C) during 24 h, classical analyses have been applied to the iron ditelluride layered structures. A good crystalline state with a preferential orientation of the crystallites along (111) direction has been recorded. Moreover, additional opto-thermal investigation and analyses within the framework of the Lattice Compatibility Theory gave plausible explanation for prompt temperature-dependent incorporation of tellurium element inside hematite elaborated matrices

Growth of Cu2SnS3 thin films by solid reaction under sulphur atmosphere

Cu2SnS3 thin film have been synthesized by solid state reaction under vapour sulphur pressure at 530 °C, during 6 h, via a sequentially deposited copper and tin layers Cu/Sn/Cu…Sn/Cu/Sn. The structure and the composition were characterized by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Electron Probe Micro Analysis (EPMA). X-ray diffraction revealed that as the deposited film crystallizes in the cubic structure and the crystallites exhibit preferential 111 orientation of the grains. Moreover, EPMA analysis confirmed that the obtained film is stoichiometric. The SEM study shows the presence of spherical particles of ≈100–120 nm diameters. The optical absorption coefficient and band gap of the film were estimated by means of transmission and reflection optical measurements at room temperature. A relatively high absorption coefficient in the range of 104 cm−1 was indeed obtained and the band gap value is of the order of 1.1 eV. On the other hand, the electrical conductivity of Cu2SnS3 film prepared in the present experiment is suitable for fabricating a thin film solar cell based on not cheaper and environmental friendly material