In recent years, antimony sulfide (Sb2S3) has been investigated as a photovoltaic absorber material due to its suitable absorber coefficient, direct band gap, extinction coefficient, earth-abundant, ...and environmentally friendly constituents. Therefore, this work proposes Sb2S3 film preparation by an effective two-step process using a new graphite box design and sulfur distribution, which has a high repeatability level and can be scalable. First, an Sb thin film was deposited using the RF-Sputtering technique, and after that, the samples were annealed with elemental sulfur into a graphite box, varying the sulfurization time from 20 to 50 min. The structural, optical, morphological, and chemical characteristics of the resulting thin films were analyzed. Results reveal the method’s effectivity and the best properties were obtained for the sample sulfurized during 40 min. This Sb2S3 thin film presents an orthorhombic crystalline structure, elongated grains, a band gap of 1.69 eV, a crystallite size of 15.25 Å, and a nearly stoichiometric composition. In addition, the formation of a p-n junction was achieved by depositing silver back contact on the Glass/FTO/CdS/Sb2S3 structure. Therefore, the graphite box design has been demonstrated to be functional to obtain Sb2S3 by a two-step process.
A novel, green route for pre-exfoliation of graphite based on a biodegradable polymer and high-power ultrasound is presented. Candelilla wax (CW), derived from the leaves of the candelilla plant, has ...been used for the first time as a natural non aqueous medium to induce the pre-exfoliation of expanded graphite (EG) under ultrasonic irradiation in an economical way. The proposed method uses also D-limonene as a natural organic solvent for reducing viscosity and increasing the affinity between the polar groups of EG and candelilla wax, thus improving the intercalation/exfoliation of EG. The quality of dispersion of the nanofiller in the natural wax matrix has been evaluated using multiple techniques. The addition of EG to wax and use of ultrasonic treatment leads to a reduced crystallinity, probably due to restrictions of the molecular movements, improved thermal stability of wax, and to an increased shear thinning exponent, which are all indicative of a high degree of EG dispersion. The ultrasonic dynamic mechanical results suggest a reduction in the cluster size and a better filler dispersion in the wax matrix promoted by polar or chemical reactions between the CW fractions and the graphite stacks, which was observed by XPS analysis. The results were compared to those obtained with paraffin, a synthetic wax, and confirmed the dispersion improvement obtained by using natural wax as a pre-exfoliating medium.
Transparent conducting films (TCFs) are made of different single-walled (SW) or multi-walled (MW) carbon nanotubes (CNTs), some of them previously modified by chemical or physical processes. The TCFs ...are prepared by spray-coating of CNT surfactant dispersions over glass substrates. Among pristine CNTs, laser-grown SWCNTs lead to the lowest resistivity, even though good results can be achieved with other selected SW or MWCNTs. Ultracentrifugation of the SWCNT dispersions can be utilized for improving the characteristic SWCNT spectroscopic signals. Controlled oxidation, acid treatment, and covalent functionalization with aromatic organic groups can be applied to CNT solid powders without substantially increasing the resulting TCF resistivity. The oxidative transformation of arc-discharge MWCNTs into graphene nanoribbons relatively improves their TCF performance. The positive effects of TCF washing with water or oxidant acids are quantified for various SWCNT types. Red and green inks, enriched in metallic or semiconducting SWCNTs, are obtained by the gel-chromatographic method, all the fractions being useful for the preparation of TCFs. Thus, it is shown that different physical and chemical processes can be performed on CNTs before or after their deposition, demonstrating a great chemical versatility for CNT-TCFs.
•Transparent conducting films are fabricated of eight carbon nanotube materials.•Carbon nanotubes for the films can bear many physicochemical transformations.•Certain nanotube electronic properties can vary without losing film conductivity.•Single-walled carbon nanotubes are sorted by the gel chromatography method.•Graphene nanoribbons are also tested.
In recent years, antimony sulfide (Sb
S
) has been investigated as a photovoltaic absorber material due to its suitable absorber coefficient, direct band gap, extinction coefficient, earth-abundant, ...and environmentally friendly constituents. Therefore, this work proposes Sb
S
film preparation by an effective two-step process using a new graphite box design and sulfur distribution, which has a high repeatability level and can be scalable. First, an Sb thin film was deposited using the RF-Sputtering technique, and after that, the samples were annealed with elemental sulfur into a graphite box, varying the sulfurization time from 20 to 50 min. The structural, optical, morphological, and chemical characteristics of the resulting thin films were analyzed. Results reveal the method's effectivity and the best properties were obtained for the sample sulfurized during 40 min. This Sb
S
thin film presents an orthorhombic crystalline structure, elongated grains, a band gap of 1.69 eV, a crystallite size of 15.25 Å, and a nearly stoichiometric composition. In addition, the formation of a
was achieved by depositing silver back contact on the Glass/FTO/CdS/Sb
S
structure. Therefore, the graphite box design has been demonstrated to be functional to obtain Sb
S
by a two-step process.
In recent years, antimony sulfide (Sbsub.2Ssub.3) has been investigated as a photovoltaic absorber material due to its suitable absorber coefficient, direct band gap, extinction coefficient, ...earth-abundant, and environmentally friendly constituents. Therefore, this work proposes Sbsub.2Ssub.3 film preparation by an effective two-step process using a new graphite box design and sulfur distribution, which has a high repeatability level and can be scalable. First, an Sb thin film was deposited using the RF-Sputtering technique, and after that, the samples were annealed with elemental sulfur into a graphite box, varying the sulfurization time from 20 to 50 min. The structural, optical, morphological, and chemical characteristics of the resulting thin films were analyzed. Results reveal the method’s effectivity and the best properties were obtained for the sample sulfurized during 40 min. This Sbsub.2Ssub.3 thin film presents an orthorhombic crystalline structure, elongated grains, a band gap of 1.69 eV, a crystallite size of 15.25 Å, and a nearly stoichiometric composition. In addition, the formation of a p-n junction was achieved by depositing silver back contact on the Glass/FTO/CdS/Sbsub.2Ssub.3 structure. Therefore, the graphite box design has been demonstrated to be functional to obtain Sbsub.2Ssub.3 by a two-step process.
Tin sulfide (SnS) thin films were deposited by the chemical bath deposition technique. The used procedure allows us to obtain orthorhombic SnS in 3.5 h and achieve thicknesses of 390 nm. We study the ...influence of deposition times, percentage of Sn precursor, and post-annealing on the structural and optical properties. The X-ray diffraction measurements of SnS films prepared at a deposition time of 3 h showed orthorhombic structure with characteristic peaks of SnS2. However, increasing the deposition time and the Sn precursor, the orthorhombic SnS phase in these samples becomes predominant. Thin-film morphologies and thicknesses were identified by scanning electron microscopy (SEM). An increase in bandgap from 1.41 eV to 1.56 eV was observed by increasing Sn precursor. The optical properties remain constant after air annealing of 285 °C. Low-temperature photoluminescence spectra show emission bands at 2.5 eV attributed to the presence of SO2. Other deep level transitions were observed at about 0.9 eV, probably due to oxygen.
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