FeS Thin Film Research Articles

In situ moulded troilite 2H phase FeS ultrathin electrodes via pulsed laser deposition for flexible solid state high capacity supercapacitor besides boosted electrocatalytic oxygen evolution reaction

Troilite 2H phase FeS thin film nanostructures as next-generation green (clean) energy storage novel material for eco-friendly, wearable/portable multifunctional devices.

Structural, Morphological and Optical Study of Manganese Doped FeS (Mackinawite) Nanostructures by Chemical Bath Deposition (CBD) Technique

Abstract: Fe1-xMnxS thin films with concentration x=0.02, 0.04, 0.06, 0.08, 0.1 have been deposited on glass substrates by a simple Chemical Bath Deposition (CBD) method at 90 oC. The X-ray Diffraction analysis of deposited thin films revealed the growth of mono-phasic mackinawite (FeS) structure with crystallite size in the range from 4.06 to 5.95 nm as a function of manganese concentrations. The other structural parameters like stacking faults, dislocation density and lattice strain affirmed the improvement in crystal structure and phase stability in manganese doped FeS thin films. Scanning Electron Micrographs depicted the growth of nano-flakes and nano-flowers in case of pure FeS thin films while for manganese doped iron sulfide thin films, homogeneity of the deposited material was observed to improve with distinct boundaries of almost spherical nanostructures. The direct energy band gap of FeS mono-phasic thin films was observed to decrease from 2.23 to 1.89 eV as the concentration of manganese increases in host lattice. The prepared thin films with tunable optical properties would have potential applications in energy conversion and optoelectronic devices.

The structural, morphological, and optical study of chemical bath deposition and a spin coating deposited mackinawite FeS thin films

The structural, morphological, and optical study of chemical bath deposition and a spin coating deposited mackinawite FeS thin films

Analysis and characterization of manganese doped FeS thin films

Fe1-xMnxS thin films with concentration have been deposited on glass substrates by a simple Chemical Bath Deposition (CBD) method at 90 oC. The X-ray Diffraction analysis of deposited thin films revealed the growth of mono-phasic mackinawite (FeS) with crystallite size in the range from 4.06 to 5.95 nm as a function of manganese concentrations. The other structural parameters like stacking faults, dislocation density and lattice strain affirmed the improvement in structure and phase stability in manganese doped FeS thin films. Scanning Electron Micrographs depicted the growth of nano-flakes and nano- flowers in case of pure FeS thin films while for manganese doped iron sulfide thin films, homogeneity of the deposited material was observed to improve with distinct boundaries of almost spherical nanostructures. The direct energy band gap of FeS mono-phasic thin films was observed to decrease from 2.23 to 1.89 eV as function of doping concentration. The prepared thin films with tunable optical properties would have potential applications in energy conversion and optoelectronic devices.

Biological approach synthesis and characterization of iron sulfide (FeS) thin films from banana peel extract for contamination of environmental remediation

Biological approach synthesis and characterization of Iron Sulfide (FeS) thin films from banana peel extract for contamination remediation of environment studied. Iron chloride, Sodium thiosulfate and Ethylene-di-amine-tetra acetate (EDTA) were used as precursor solutions without further purification. The nanoparticle of banana peel was extracted and prepared with synthesized FeS thin films and analyzed by X ray-diffraction for structural examination, Scanning electron microscope (SEM) for surface morphological analysis, Ultra-violet-visible-spectrometer (UV–Vis) and photo-luminescence spectro-photo-meter (P-L) for optical characterizations. XRD peaks are shown with recognized to (110), (200), (310), and (301) crystalline planes. The occurrence of this deflection peak are recognised the FeS crystal segment of the tetragonal crystalline systems. SEM micrographs of the films prepared biological method show the distribution of grains, which cover the surface of the substrate completely and are uniform and films deposited purely have defects. The photo-luminescence, absorbance, and transmittance strength of banana peel extract FeS thin film is greater than pure FeS thin films in which wide-ranging and symmetries groups were perceived. In the present study, the comparison of pure FeS thin films and Nano synthesized banana peel extract with FeS thin films was studied. It is observed that Nano synthesized banana fibre absorbs higher than pure FeS thin films in solar cell application. Finally, green synthesis is an ecofriendly, easy and cheap promising method for the fabrication of thin films for solar cell applications.

Stabilization and heteroepitaxial growth of metastable tetragonal FeS thin films by pulsed laser deposition

Pulsed laser deposition, a non-equilibrium thin-film growth technique, was used to stabilize metastable tetragonal iron sulfide (FeS), the bulk state of which is known as a superconductor with a critical temperature of 4 K. Comprehensive experiments revealed four important factors to stabilize tetragonal FeS epitaxial thin films: (i) an optimum growth temperature of 300 °C followed by thermal quenching, (ii) an optimum growth rate of ∼7 nm min−1, (iii) use of a high-purity bulk target, and (iv) use of a single-crystal substrate with small in-plane lattice mismatch (CaF2). Electrical resistivity measurements indicated that none of the films exhibited superconductivity. Although an electric double-layer transistor structure was fabricated using the tetragonal FeS epitaxial film as a channel layer to achieve high-density carrier doping, no phase transition was observed. Possible reasons for the lack of superconductivity include lattice strain, off-stoichiometry of the film, electrochemical etching by the ionic liquid under gate bias, and surface degradation during device fabrication.

Molecular Beam Epitaxy Growth of Tetragonal FeS Films on SrTiO3 (001) Substrates**Supported by the National Natural Science Foundation of China, the Ministry of Science and Technology of China, and the Specialized Research Fund for the Doctoral Program of Higher Education under Grant No 20130002120033.

We report the successful growth of the tetragonal FeS film with one or two unit-cell (UC) thickness on SrTiO3(001) substrates by molecular beam epitaxy. Large lattice constant mismatch with the substrate leads to high density of defects in single-UC FeS, while it has been significantly reduced in the double-UC thick film due to the lattice relaxation. The scanning tunneling spectra on the surface of the FeS thin film reveal the electronic doping effect of single-UC FeS from the substrate. In addition, at the Fermi level, the energy gaps of approximately 1.5 meV are observed in the films of both thicknesses at 4.6 K and below. The absence of coherence peaks of gap spectra may be related to the preformed Cooper-pairs without phase coherence.

First report on a FeS-based 2 V operating flexible solid-state symmetric supercapacitor device

Device grade application of FeS thin film deposited by successive ionic layer adsorption and reaction (SILAR) method at room temperature.

Hydroxyl solvents prompted interwoven morphological deposition of iron sulfide nanoparticles as an effective counter electrode for quantum dot sensitized Solar cell

A low-cost, stable and efficient FeS thin film counter electrode (CE) was fabricated for quantum dot-sensitized solar cells (QDSSCs) by a facile chemical bath deposition method using different acidic hydroxyl solvents (ethanol, isopropanol, and tert-butanol) and triethanolamine. The choice of solvents greatly affected the surface morphology and thickness of FeS CEs. Apart from surface morphology, the increase in the atomic percentage of sulfur in tert-butanol and triethanolamine-mediated FeS also plays a crucial role in increasing the electrocatalytic activity of the CE. The QDSSC’s power conversion efficiency was 2.15%, which is attributed to the high fill factor (FF) of 0.443. The obtained PCE is far better than the previously reported value of 1.76% for FeS in QDDSC’s. Excellent stability of the photoelectric performance of the FeS CE is also demonstrated. The enhanced electrochemical performance of the interwoven FeS networks can be attributed to their unique morphology, which possesses a shorter diffusion length of the ions and easier transportation of the electrons.

Synthesis of mackinawite FeS thin films from acidic chemical baths

The growth of monophasic iron sulfide thin films onto glass substrates has been achieved by chemical bath deposition at acidic values of pH. Powder X-ray diffraction (p-XRD) confirms the deposition of tetragonal FeS (mackinawite) with preferred orientation along (001) plane. The crystallite size estimated by Scherrer equation was found to be 14nm. Scanning electron microscopy (SEM) shows the formation of nanoflakes as base layer and nanoflowers as top layer. Energy Dispersive X-ray (EDX) analysis of the deposited iron sulfide thin films shows the iron to sulfur ratio close to 1:1 confirming the deposition of FeS. UV–vis absorption spectroscopy showed a blueshift due to the nanosize crystallites FeS with a band gap of 1.87eV.

The influence of the electrolyte on chemical and morphological modifications of an iron sulfide thin film negative electrode.

The chemical and morphological modifications of FeS thin film as anode material for LiBs have been studied in detail in two classical electrolytes usually used in Li-ion batteries: 1 M LiClO4-PC and 1 M LiPF6-EC/DMC. The X-ray photoelectron spectroscopic (XPS) analysis evidenced the formation of a solid electrolyte interphase (SEI) that contains a more significant amount of inorganic salt residues formed in LiPF6-EC/DMC than in LiClO4-PC, which is likely to increase the ionic resistivity of the SEI, thus impeding the lithiation-delithiation in the first cycles while improving its reversibility. Ion depth profiles performed by time-of-flight secondary ion mass spectrometry (ToF-SIMS) show volume expansion-shrinkage of the thin film leading to cracking and pulverization of the electrode material, which is also confirmed by scanning electron microscopy (SEM) analysis. The prolonged cycling results in penetration and accumulation of the electrolyte in a bulk electrode with accumulation of the inorganic species in the inner part of the SEI enhanced in a fluoride-containing electrolyte. Cycling in these two different electrolytes leads also to formation of two different electrode morphologies: with a compact electrode structure formed in LiClO4-PC and a foam-like, porous structure in LiPF6-EC/DMC. A model of this conversion-type thin film electrode modification based on these thorough spectroscopic and microscopic analyses induced by cycling in two different electrolytes is proposed.

Nanocrystalline FeS thin film used as an anode in photo-electrochemical solar cell and as hydrogen peroxide sensor

Nanocrystalline FeS thin films have been deposited on fluorine doped tin oxide (FTO) coated glass substrates by the thermal decomposition of a precursor complex in aqueous solution. The resulting FeS films were characterized by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The optical properties of the deposited films were recorded with the help of UV–vis absorption and photoluminescence spectroscopic measurements. Electrochemical and photoelectrochemical properties were studied using these FeS thin films. A short circuit photocurrent (Isc) of 5.7mA/cm2, an open circuit photovoltage (Voc) of 0.64V, a fill factor (FF) of 0.35 and a conversion efficiency (η) of 2.6% were obtained using these FeS films as photo-anodes in a photoelectrochemical (PEC) solar cell under white light illumination of 50mW/cm2. Repeated illumination cycles showed that the film displayed a reasonable response and photosensitivity. The FeS thin films also showed excellent electrochemical properties towards the reduction of hydrogen peroxide in aqueous solution and could be employed as a H2O2 sensor. The proposed sensor exhibited a good linear response in the range of 0.5–1300μM with a detection limit of 0.12μM under optimum conditions.

Deposition of copper‐doped iron sulfide (CuxFe1−xS) thin films using aerosol‐assisted chemical vapor deposition technique

AbstractCopper‐doped iron sulfide (CuxFe1−xS, x = 0.010–0.180) thin films were deposited using a single‐source precursor, Cu(LH)2Cl2 (LH = monoacetylferrocene thiosemicarbazone), by aerosol‐assisted chemical vapor deposition technique. The Cu‐doped FeS thin films were deposited at different substrate temperatures, i.e. 250, 300, 350, 400 and 450 °C. The deposited thin films were characterized by X‐ray diffraction (XRD) patterns, Raman spectra, scanning electron microscopy, energy dispersive X‐ray analysis (EDX) and atomic force microscopy. XRD studies of Cu‐doped FeS thin films at all the temperatures revealed formation of single‐phase FeS structure. With increasing substrate temperature from 250 to 450 °C, there was change in morphology from wafer‐like to cylindrical plate‐like. EDX analysis showed that the doping percentage of copper increased as the substrate temperature increased from 250 to 450 °C. Raman data supports the doping of copper in FeS films. Copyright © 2010 John Wiley & Sons, Ltd.

Structural and morphological characterization of chemical bath deposition of FeS thin films in the presence of sodium tartrate as a complexing agent.

In this paper, we presented the results of X-ray diffraction and scanning electron microscopy of the ironsulphide thin films prepared using a simple and cost effective chemical bath deposition method. The effectsof solution concentration and pH on the structural and morphological properties of thin films were studiedin the presence of sodium tartrate as a complexing agent. The thin films deposited using higher solutionconcentration showed higher number of FeS peaks and larger grain size according to X-ray diffraction andscanning electron microscopy results, respectively as compared with other solution concentrations. On theother hand, when the thin films were deposited at higher pH, the number of FeS peaks reduced to two peaksand the films showed incomplete coverage of material over the surface of the substrate with the smaller grainsize. Key Words: Chemical bath deposition; Iron sulphide; Scanning electron microscopy; Thin films

Lithium silicon sulfide as an anode material in all-solid-state lithium batteries

The electrochemical properties of Li 2SiS 3 were investigated in a solid electrolyte. Li 2SiS 3 was converted to elemental Si, and the resultant Si was formed into Si–Li alloy in the reduction process; however, the reverse reaction was not completed due to the loss of electronic conduction upon reoxidation. FeS was dispersed as a conductive additive in Li 2SiS 3 films by pulsed laser deposition (PLD). The addition allowed successive reactions to proceed at a large capacity with small capacity-fading during the cycling process in spite of the small FeS fraction. This result indicates that Li 2SiS 3 + FeS thin film is a promising anode for solid-state lithium batteries.