Properties Of ZnS Thin Films Research Articles

Structural, morphological, and optical bandgap properties of ZnS thin films: a case study on thickness dependence

Structural, morphological, and optical bandgap properties of ZnS thin films: a case study on thickness dependence

Effect of Triton X-100 surfactant on structural, morphological, and optical properties of ZnS thin films deposited by spin coating method

Effect of Triton X-100 surfactant on structural, morphological, and optical properties of ZnS thin films deposited by spin coating method

Modification induced by 120 MeV Ag ion irradiation in ZnS

We report the structural, morphological, and optical properties of ZnS thin films before and after swift heavy ion (SHI) irradiation of 120 MeV Ag ions. These films were deposited by the spin coating method on the glass substrate and irradiated at various ion fluencies from 1 × 1011 to 1 × 1013 ions/cm2. The Grazing Incidence X-ray diffraction (GIXRD), Scanning electron microscopy (SEM), UV–visible transmittance, Photoluminescence (PL), and Raman Spectroscopy were used to characterize these ZnS thin films. The GIXRD patterns show a mixed phase of cubic and hexagonal structure after the ion irradiation. The crystallite sizes of pure and irradiated films are significantly modified. Raman spectroscopy shows a slight increase in the intensity of the 3LO mode of ZnS on irradiation. The SEM image shows nanoflake-like structures in pristine, and the irradiated thin films depict various morphologies (rod, platy, and sphere-like). UV–visible shows a cut-off wavelength at 339 nm and the spectra are blue-shifted with the increase in ion fluence. The Tauc plots reveal the increase in the band gap. The intensity of PL decreases with ion irradiation. Hence the analytical results show that the structural and optical properties of ZnS thin films are altered on swift heavy ion irradiation which may have potential applications in optoelectronic applications.

Effect of Ag incorporation on the microstructure and properties of ZnS thin films

In this study, ZnS thin films doped with different content of Ag were deposited on quartz glass substrates by RF magnetron sputtering technique and were annealed at 600 °C in sulfur vapor. The crystal structure, grain size, surface morphology, composition, optical properties and defects of the doped ZnS thin films were analyzed by X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), UV–Vis spectroscopy and positron annihilation doppler broadening spectroscopy (DBS). The results showed that all films exhibited the cubic sphalerite structure with a preferred orientation along the (111) crystal plane, and the composition of the doped films were more consistent with the stoichiometric ratio compared to the undoped film. The grain size gradually increased as the Ag content grew, indicating the improvement of crystallinity of the ZnS thin films. Besides, the bandgap values of these ZnS films with good optical transparency in the visible region were decreased from 3.87eV to 3.53eV as the Ag content grew. DBS results also showed that the defect concentration of ZnS films gradually decreased from the surface to the inner layer, and the film defects decreased with the increase of Ag content. However, the types of defects changed when the Ag content increased. Furthermore, the results showed Ag also has an effect on the porosity of ZnS thin films.

Effect of Lanthanum Doping on Properties of ZnS Thin Films for Water Splitting

A chemical bath deposition technique was used to create the transparent, finely adherent ZnS and Lanthanum doped ZnS thin films on a glass substrate. The films were obtained in a water bath with reaction solutions containing Zinc, Lanthanum precursors, and trisodium citrate as a complexing agent. The amorphous nature of the films was confirmed by an X-ray diffractometer and the porosity of the films was checked by field emission scanning electron microscope. The presence of Lanthanum in ZnS films was confirmed by EDS. To find the band gap UV-Visible spectroscopy analysis was carried out. The impurity phase and the Raman modes were recognized by Raman spectroscopy. Further studies on the water splitting and photocatalytic degradation of organic dyes using La-ZnS nanomaterials are underway in our laboratory.

ZINC SULFIDE ANTI-REFLECTIVE THIN FILM COATING FOR GERMANIUM OPTICAL WINDOWS

In this work, Anti-reflective thin film is made on Germanium (Ge) optical window, which is one of the most used materials in thermal imaging systems. ZnS material was used its optical transmittance between 2-14 m and due to the fact that it has a refractive index proportional to the refractive index of Ge. ZnS thin films have been prepared by Radio Frequency (RF) magnetron sputtering on Germanium (Ge) optical windows for anti-reflection coating (ARC). ZnS films were produced at different thicknesses using RF sputtering system working pressures under 3, 20 and 30 mTorr. The other RF systems parameters such as RF power, deposition temperature were kept constant for all depositions. Crystal structures, optical and surface properties of ZnS thin films were characterized with X-ray diffraction (XRD), Atomic force microscopy (AFM), Fourier transform ınfrared (FTIR) and UV-VIS transmission spectrometer. The characterization results of Ge optical windows coated ZnS thin films grown at 3 mTorr pressure show that high optical transmission and good crystallinity in ınfrared wavelength region (2-14 um).

Structural and optical properties of ZnS thin films prepared at different flow rates by spray pyrolysis technique

In this work, we examined the influence of flow rate on the characteristics of ZnS thin films sprayed onto glass substrates at a constant temperature by a spray pyrolysis method. A deposition was carried out for different flow rate. The structural properties using the X-ray diffraction (XRD) shows an influence on the crystalline quality. The optical measurement with a UV–Visible spectrophotometer represents the semiconductor properties of ZnS with an optical band gap that varies with the variation of the flow rate from 3.06 to 3.62 eV.

Comprehensive analysis of microstructural, optical and electrical properties of ZnS thin films deposited by cost effective SILAR technique

Cost effective SILAR technique was utilized to synthesis uniform ZnS thin films by varying solution molarity. The structural, composition, optical, and transport properties of zinc sulphide films synthesized were explored in detail. The properties of the films with different thickness were studied using, XRD, SEM-EDS, UV–visible spectroscopy, and I-V probe station. XRD analysis revealed the cubic structure of as prepared and heat treated ZnS films. The films comprised of moderate sized crystallites(15 nm). The films were well adherent and EDS analysis confirmed the marginal stoichiometry of the films. Significant optical absorption was seen in the near UV region. The films showed high absorption coefficient values (106 cm−1). The optical band gap of the as prepared and heat-treated films was found to be in the range 3.1 eV to 3.6 eV. The penetration depth showed the cut off wavelength in UV region. The electrical properties were studied using silver ohmic contacts. The resistivity of the films was in the range 102 Ω cm, and the carrier concentration was observed to be of the order of and 1014 cm3. The sufficiently thick ZnS thin films with high absorption coefficient can be used for UV photodetector applications.

Structural characterization of synthesized Al-doped ZnS nanoparticles deposited on glass substrate

This study aimed to determine the effect of Al-doping on the physical properties of ZnS thin films. The pulsed-laser deposition technique was used to prepare ZnS and Al-doped ZnS (AZS) thin films on soda-lime glass slides. The Al concentration of 0–6% was used. Further, XRD spectroscopy was employed to confirm the structures of the ZnS and AZS films, following which the values of parameters such as crystal plane spacing, crystallite grain size, microstrain, and dislocation density were calculated. Regarding ZnS, the result showed a broad pattern corresponding to the (111) plane of ZnS. There was a variation of 0.313–0.316 nm in the d-spacing, which decreased as the concentration of Al in the ZnS films increased. The crystallite size was found to be 0.80–671.24 nm. Notably, the crystallite size was affected by the Al concentration. The change in the a aluminum content from 0 to 8% make change in thee strain increase from 0.00046 to 0.0031. Also, as the Al-doping increased, the dislocation-density reduced from 1.54 to 0.00000221 mg.cm-3 . The values obtained in this work were consistent with published standards.

Influence of Solvents on Properties of ZnS Thin Films Synthesized by Chemical Spray Pyrolysis Technique

Abstract: In this paper, the influence of solvents on the structural, optical, surface and electrical properties of spray-deposited ZnS thin films has been studied. Different precursor mixtures were prepared from ethylene glycol, deionized water and alcohol solvents and sprayed on heated glasses via a simple and cost-effective technique known as spray pyrolysis. XRD patterns confirmed cubic and tetragonal phases of synthesized ZnS material. The optical analysis of the synthesized ZnS films showed that films prepared using ethylene glycol solvent have the highest transmittance and the best bandgap (3.61 eV). Surface morphology showed the absence of voids and pinholes in the Scanning Electron Micrograph of ZnS film prepared from ethylene glycol and electrical studies showed that ZnS films prepared using the same solvent have the lowest resistivity. Keywords: ZnS, Thin film, Spray pyrolysis, Bandgap, Morphology.

The Effect of the Deposition Method on the Structural and Optical Properties of ZnS Thin Films

ZnS is a wide band gap material which was proposed as a possible candidate to replace CdS as a buffer layer in solar cells. However, the structural and optical properties are influenced by the deposition method. ZnS thin films were prepared using magnetron sputtering (MS), pulsed laser deposition (PLD), and a combined deposition technique that uses the same bulk target for sputtering and PLD at the same time, named MSPLD. The compositional, structural, and optical properties of the as-deposited and annealed films were inferred from Rutherford backscattering spectrometry, X-ray diffraction, X-ray reflectometry, Raman spectroscopy, and spectroscopic ellipsometry. PLD leads to the best stoichiometric transfer from target to substrate, MS makes fully amorphous films, whereas MSPLD facilitates obtaining the densest films. The study reveals that the band gap is only slightly influenced by the deposition method, or by annealing, which is encouraging for photovoltaic applications. However, sulphur vacancies contribute to lowering the bandgap and therefore should be controlled. Moreover, the results add valuable information towards the understanding of ZnS polymorphism. The combined MSPLD method offers several advantages such as an increased deposition rate and the possibility to tune the optical properties of the obtained thin films.

Doping and annealing effects on structural, optical and electrical characteristics of Sn-doped ZnS thin film

This work presents the fabrication of Zn1−xS:Snx thin films using the chemical bath deposition method and investigates the effects of Sn doping and annealing temperature on the structural, optical and electrical properties of ZnS thin films. The XRD patterns show that the relative intensities of the major diffraction peaks increase with Sn dopant incorporation and annealing temperature. Because high-temperature annealing forms several nucleation centers throughout the lattice and dopant incorporation enhances point defects leading to crystallite boundary mobility enhancement, crystallinity is also improved. UV–vis-NIR spectrophotometric studies revealed that the films have good transmittance that is larger than 75% in both visible and near-infrared regions and their optical bandgap ranges from 3.34 eV to 3.90 eV. Both the Sn content and annealing temperature cause the transmittance and the optical bandgap to rise. The absorption edge shifts towards the longer wavelength for higher Sn contents and annealing temperatures. Also, the decreased Urbach energy with increased Sn content or annealing temperature can be attributed to the reduced structural disorders and dislocations of ZnS crystals that are indicated by improved crystallinity. Electrical characterization by the two-point probe method exhibits that at higher annealing temperature grain boundary scattering limits the number of mobile carriers by increasing interatomic binding. On the other hand, due to increased carrier concentration and decreased dislocations resulting from the Sn content or annealing, localized carriers dominate in the bulk crystal state and require higher activation energy to replace an interstitial atom and excite the bulk states.

Optical Properties of Zinc Sulphide Thin Films Coated with Aqueous Organic Dye Extract for Solar and Optoelectronic Device Applications

Optical properties of ZnS thin films coated with organic dye extract on different Zn2+ concentrations from ZnSO4 are presented in this study. The effects of concentration and post-deposition annealing temperatures on the optical properties of the films were investigated. Aqueous dye extract-coated ZnS nanocrystals, were prepared by a simple and low-cost chemical bath deposition method. Results obtained revealed that optical properties of the films were modified by concentration and post-deposition annealing temperature. Increasing concentration reduced the transparency of the films. Annealing increased the transparency of the films except for films deposited with 0.1M concentration of ZnSO4. In general, the heat-treated layers were found to transmit better than the as-deposited layers. The analysis of energy band gap showed a reduction in band gap with increasing Zn2+ concentration of the as-deposited films. It also indicated that post-deposition annealing, increased energy band gap except for films deposited with 0.1M concentration of ZnSO4. The relationship between the energy band gap with both concentration and post-deposition annealing fit into the quadratic model with high R2 values. The range of values of 3.889–3.981eV recorded for the band gaps is within the range for application in diverse solar architecture and optoelectronic devices.

Effect of Na doping on the properties of ZnS thin films and ZnS/Si heterojunction cells

Undoped and 1, 5, 10 and 15% sodium doped ZnS thin films were grown on glass and Si substrates by spray pyrolysis. Effect of Na doping on the properties of ZnS thin films were investigated via XRD, SEM, UV–Visible spectrometry and resistivity measurements. Photovoltaic behavior of ZnS/Si heterostructure cells were investigated by current-voltage measurements. Band gap energy of ZnS film was decreased to 3.42 eV from 3.66 eV and resistivity of the film was decreased to 2.00 × 105 Ω.cm from 5.17 × 105 Ω.cm with increasing Na doping concentration. Photovoltaic performance of ZnS/Si heterostructure cell was improved and power conversion efficiency was increased to 5.06% from 2.20%.

Physical Properties of ZnS Thin Films Prepared by Low-temperature Sulfidation

In the article, Zn thin films were deposited on the glass substrates at room temperature by magnetron sputtering from a zinc target. And ZnS thin films were prepared by annealing Zn thin films in sulfur vapor and Ar gas at 200 and 400 ℃. The microstructure defects, crystallizations, surface morphology and optical properties of the samples were analyzed by PAT(positron annihilation technique), XRD(X-ray diffraction), SEM(scanning electron microscopy) and UV-VIS spectrophotometer. The resultant ZnS thin films exhibited a high optical transmittance of about 80% in the visible region. With the increase of sulfidation time, the band-gap value was increased from 3.55 to 3.57 eV, and the S/Zn atomic ratio was enhanced from 0.54 to 0.89, implying an obvious improvement of ZnS film quality. This demonstrated that the excess-sulfur problem in the ZnS films was well solved compared with those samples prepared by sulfidation in the vacuum-sealed quartz-glass ampoules. Besides, the structural defects of the thin films before and after sulfidation were investigated by positron annihilation Doppler broadening measurements. It was found that the S parameter of the samples after sulfidaton was greater than that before sulfidation, implying the higher structural defect concentration for the former.

Physical properties of Al-doped ZnS thin films prepared by ultrasonic spray technique

The objective of this work is study the effect of Al doping on physical properties of ZnS thin films. Undoped and Al-doped ZnS films were deposited by ultrasonic spray method using atomizer on glass substrates at 500°C. The films were synthesized with different Al doping ratio ranged from 0 to 6 %. The films structure and morphology were studied by means of X-ray diffraction (XRD), scanning electron microscopy. The films optical and electrical properties were studied by UV-VIS spectrophotometer and four probes method. The structural analysis indicated that the doped ZnS films have a hexagonal structure with strong preferred orientation (002) direction for all Al concentration. The (SEM) images revealed a dense surface, highly homogeneous and better adherent to the substrate surface. The average crystallites size increases from 32 nm to 43.8 nm with increasing of Al concentrations. UV–vis–NIR spectro-photometric measurements showed that the films were good transparent (60–73%) in the visible region. The films band gap is ranged from 3.7 eV to 3.9 eV. The performed electrical measurements indicate that the films electrical resistivity depends on the doping ratio. The latter was decreases with increasing the Al concentration from 8 × 104 to 3.35 × 104Ω.cm.

Optical and structural investigation of ZnS:Cu thin films synthesized by spray pyrolysis

We have investigated the effect of Cu dopant and substrate temperature on the structural and optical properties of ZnS thin films deposited on glass substrate by spray pyrolysis technique. The glass substrate temperature varied from 300 to 450 °C. Different characterization methods such as X-ray diffractometry, EDS, SEM, and Raman scattering analyses for studying the structural, morphological and optical properties of the prepared ZnS and ZnS:Cu samples were carried out. Improvement in crystallization, increase in crystallite size and also better growth orientation along the (111) direction are clearly evident due to the increase in the substrate temperature. Cu doping effects on the displacement of diffraction peaks towards larger angles and decrease in crystallite size which caused by this impurity are the main results of this studies. The absence of any other impurity in samples, smooth surface, homogenous structure and spherical shape of crystals have approved by EDS analysis and SEM imagining, respectively. Raman scattering spectra of ZnS and ZnS:Cu in ambient condition not only indicate E and A Raman first order scattering of ZnS, but also indicate an intense peak about 334 cm−1 related to surface optical phonon mode in this nanostructure. Optical properties of thin films determined by UV–Vis spectroscopy and the energy band gap was calculated with ZnS doping rates. Photoluminescence analysis and origin of green emission peak at 533 nm and red peak at 745 nm were discussed.

Impact of Hydrogen flow rate on physical properties of ZnS thin films: As potential buffer layer in solar cells

The exceptional need of potential Cd-free buffer layer in thin film solar cell devices motivated us to study the role of post-deposition Hydrogen annealing for the optimization of physical properties of ZnS thin films. The deposited films of thickness 200 nm were hydrogenated within the flow rate range of 50.0–150.0 sccm at 200 °C. XRD analysis revealed transformation of amorphous into cubic phase with maximum crystallinity at 150.0 sccm for films deposited on glass substrate while into wurtzite structure for films on ITO substrate with enhanced crystallinity. A mixed phase (cubic and hexagonal) at 150.0 sccm also appeared. Electrical behaviour (I–V) exhibits ohmic nature with maximum carrier concentration at 100.0 sccm. The blue shift in absorption edge and maximum of 95% transmittance were recorded in the visible region with optical energy band gap of 3.41 eV at 150.0 sccm. The reduction in surface roughness is observed in surface topographical analysis while the photoluminescence (PL) study indicated a sharp peak at 2.95 eV with strongest emission for 150.0 sccm attributed to reduction of defects at interstitial sites and passivation of grain boundaries. These results are useful to understand the Hydrogen related impurities in ZnS films and the improvement caused by hydrogenation to physical properties suited for buffer layer in solar cells.

Study of the Effect of Different Dopants on Optical Properties of ZnS Thin Films

Study of the Effect of Different Dopants on Optical Properties of ZnS Thin Films - written by Nasser Saad Al-Din -Abalh Alzoubi , Zeinab Alhassan published on 2020/03/03 download full article with reference data and citations

Structural and Optical Properties of ZnS Thin Films Fabricated by Using RF Sputtering and Rapid Thermal Annealing Process for Buffer Layer in Thin Film Solar Cells

Structural and Optical Properties of ZnS Thin Films Fabricated by Using RF Sputtering and Rapid Thermal Annealing Process for Buffer Layer in Thin Film Solar Cells