Sharif Digital Repository

Efficient electron transport layers (ETLs) play a pivotal role in the performance of solar cells. In recent years, Indium sulfide (In2S3) has been studied as a promising ETL in CuInGaS(e)2, Cu2ZnSnS(e)4, and perovskite solar cells. Despite several studies on spray-deposited In2S3, there is no complete experimental investigation on In2S3 thin films. The effect of the molar ratio of S/In and the type of indium precursor on the structural, morphological, optical, and electrical properties of sprayed-In2S3 layers has been studied. Films were characterized using x-ray diffraction, scanning electron microscopy (SEM), optical transmission (UV-Vis), Mott-Schottky analysis, four-point probe, and... 

Copper indium selenide CuInSe2(CISe) thin films were deposited by chemical spray pyrolysis (CSP) method of CuInS2(CIS) and subsequent selenization process. To study the effects of solution concentration, we prepared different precursors solution of CIS including different amount of indium salts from 0.025 to 0.100 M with In/Cu 1.25 and S/In 4. These results propose that solution concentration is critical for inflecting the morphological, optical, electrical, and electrochemical characteristics of solution-processed CISe films and device performance. The studied morphological properties of deposited samples were homogenous, crack-free with large grains in indium salt concentrations more than... 

Targeting on the selenium free, pure sulfide kesterite compound (CZTS) allows retention of the higher band gap nontoxic absorber for a single-junction solar cell. In this work, CZTS thin films were deposited by the PLD method and the Structural/optical properties, as well as Mott–Schottky analysis, were studied at different substrate temperatures. Without undergoing the sulfurization process, the single-phase CZTS thin film is prepared at 300 ℃. In the second step, a numerical simulation is performed using the solar cell capacitance simulator to study the effect of the grading layer of MoS(Se)2 on the rear side of pure sulfide kesterite based solar cells. The device with a MoSe2 coated... 

Cupric oxide (CuO) is a semiconductor of choice for photocathode in photoelectrochemical (PEC) applications due to its great sunlight absorption capability. However, photocorrosion is the main drawback of CuO. Herein, CuO/graphitic carbon nitride (g-C3N4) with a unique microstructure, enhanced PEC performance, and considerable photostability is synthesized under microwave irradiation. A facile, one-pot method is utilized to directly deposit the nanocomposite onto fluorine-doped tin oxide from a solution containing copper precursor and urea. Possible mechanism of CuO/g-C3N4 formation through this novel method is investigated. It is elucidated that controlled amounts of urea critically... 

In this study, zirconia antistatic coatings were synthesized by a simple dip coating sol-gel route on glass substrates, then applied to polymer-based composites to potentially improve their dust or water repellent capabilities. The coating solution contained a precursor (ZrCl4), solvent (isopropanol) and coupling agent. FTIR spectra confirmed ZrO2 and ZrO compounds in both solution and antistatic coating. FE-SEM images indicated ZrO2 fibers’ thickness was controlled by changing ZrCl4 concentration (150 g–15 g ZrCl4/l) or relative humidity (20%–60%) during coating drying. Fibers grew thicker when decreasing the former or increasing the latter. The surface electrical resistivity for all... 

Abstract: The effect of annealing temperature on the properties of silver thin films has been investigated. Ag thin films have been deposited on glass substrates by electron beam coating, afterward subjected to annealing in a mixed ambient of air and oxygen at 100, 200, 300, 400 and 500°C for 3 h and then cooled slowly. The crystallographic structures of the Ag thin films were studied as a function of the annealing temperature. X‑ray diffraction (XRD) was used to estimate the crystallographic texture and grain size. All the films were found to have crystalline structure. The film microstructures were studied by scanning electron microscopy (SEM). The XRD and SEM results confirmed the... 

Anti-reflection and self-cleaning coatings on the glass substrate are used to improve the performance of solar systems. TiO2 are one of the most used semiconductors for this application. In this research meso-porous TiO2 coatings (that synthesized by the sol-gel process) with the various extent of porosity (using different concentrations of Pluronic F127, as pore-forming agent) have been investigated. The coating's thickness and porosity and anti-reflective properties were studied by FE-SEM and UV/VIS spectrometer (transmission spectra test), respectively. It was found that the use of F127 leads to the formation of pores smaller than 30 nm and increases the surface roughness from 1.5 (for... 

In this research, the ZnOG hybrid thin film was produced via solgel method. The surface morphology, band gap and photoactive properties of the films were studied by means of SEM, UV–Vis and photoluminescence analysis. In addition, the ability of the thin film in photocathodic protection of carbon steel (CS) and 304 stainless steel in 3.5 wt.% NaCl and Na2S solutions under dark and UV illumination was investigated by polarization test as well as OCP and current measurements during coupling of steels with ZnOG photoanode. The mix band gap is reduced to the orders of 1.17 eV through hybridization of ZnO with graphene oxide. In both NaCl and Na2S solutions, the ZnOG thin film could effectively... 

Ti and TiN thin films were deposited by means of electron beam evaporation on stainless steel substrates, and subsequently annealed at different temperatures (650, 750 and 850 °C) in a nitrogen atmosphere. The surface morphology of the films studied by atomic force microscopy (AFM), was found to exhibit specific multifractal properties depending on the annealing temperature. It turned out that the width of the multifractal singularity spectra, f(α), decreased as the annealing temperature increased up to 750 °C, but it increased when the temperature was kept at 750 and 850 °C accompanied by the rapid development of the surface objects. The generalized fractal dimension followed a similar... 

This article investigates the basis for pressure sensor application based on the magnetic shape memory effect in membranes. Von Karmans nonlinear terms are considered in strain–displacement relationships of thin films, and a new method is presented for solution of large deflections of thin films with arbitrary boundary condition. In this study, the equations of motion of magnetic shape memory alloys are extended. In pressurized membranes, the complex distribution of mechanical stress can cause the martensitic reorientation, which is the underlying mechanism for sensing applications in magnetic shape memory alloys. To examine the obtained model, the governing equations of magnetic shape... 

The micromorphology and semiconductor properties of TiO2 thin films growth using different ion beam energies have been finely analyzed using atomic force microscopy (AFM), ultra-violet visible (UV–visible) spectroscopy and stereometric analysis. The AFM measurements and surface stereometric analysis are essential for the accurate characterization of the 3-D surface topographic features and allow the determination of the 3-D surface texture parameters that influence the optical properties of the material. The samples were divided into four groups to discuss the obtained results, according to the ion beam energy applied in the sample preparation. The results obtained from experimental... 

The morphology, structure and optical properties of zinc sulfide (ZnS) thin films prepared through radio-frequency (RF) magnetron sputtering have been analyzed using atomic force microscopy (AFM), UV–Vis–NIR spectrophotometry, X-ray diffraction, and multifractal analyses. The X-ray diffraction patterns revealed that all ZnS thin films show a single peak at around 29.6°, which has been ascribed to the (111) planes of sphalerite phase, indicating that the growth direction of the films is the [111] direction. UV–Vis–NIR transmittance spectra were used to determine the refractive index of the samples, their thickness, and their band gap energy, showing the optical and semiconductor properties a... 

The micromorphology of tantalum pentoxide (Ta2O5) thin films, deposited on glass substrates by electron gun method, has been analyzed using atomic force microscopy (AFM), UV–Vis–NIR spectrophotometry and multifractal analyses. Two samples were grown at basic pressure of 7 × 10−6 mbar, work pressures of 1.3 × 10−4 and 2.0 × 10−4 mbar, and thicknesses of 0.38 μm and 0.39 μm, respectively. Subsequently, these samples were annealed at 300 °C for 2 h. The physical, structural and optical analyses were investigated by spectroscopic ellipsometry, spectrophotometry and AFM. The measured transmittance spectra were studied based on the Swanepoel method, whose results also yielded to the estimation of... 

WO3 films with thicknesses between 550 and 853 nm were deposited on glass substrates using the electron beam evaporation method at room temperature. The microstructures and surface roughness of the films were studied by X-ray diffraction (XRD) and atomic force microscopy (AFM). It was observed that the crystalline structure of the WO3 thin films significantly changes from the amorphous to crystalline states with a crystalline texture, and the mosaicity and grain size dependent on the film thickness. The transmittance spectra of the obtained WO3 films were measured in the range from 340 to 850 nm, and the Swanepoel method was used to determine the refractive indices and the thicknesses of the... 

In this paper, we have successfully deposited Ag-Cu thin films. Nanoscale morphology and nanotexture were studied using atomic force microscopy (AFM) through fractal and stereometric parameters. Additional algorithms have been developed to study new fractal parameters such as surface entropy, fractal succolarity, and fractal lacunarity. The results revealed that as the deposition time increased, films exposed isotropies between ~65 and 82%, which were correlated to the fractal patterns, where from #3 to #5 there were greater spatial complexities. Moreover, surface roughness increased from #1 to #3, which was observed for both Sq and Sa. Similar behavior was exhibited by the other height... 

N-annulated perylene based materials show outstanding and tunable optical and physical properties, making them suitable to be charge transport materials for optoelectronic applications. However, this type of materials has so far not been well studied in solar cells. Here, we develop a new hole transport material (HTM), namely S5, based on perylene building block terms, for organic-inorganic hybrid perovskite solar cells (PSCs). We have systematically studied the influences of the film thickness of S5 on their photovoltaic performance, and a low concentration of S5 with a thinner HTM film is favorable for obtaining higher solar cell efficiency. S5 shows excellent energy alignment with... 

Microfluidic systems (MFS) provide a range of advantages in biomedical applications, including improved controllability of material characteristics and lower consumption of reagents, energy, time and money. Fabrication of MFS employs various materials, such as glass, silicon, ceramics, paper, and metals such as gold, copper, aluminum, chromium and titanium. In this review, gold thin film microfluidic channels (GTFMFC) are discussed with reference to fabrication methods and their diverse use in chemical and biomedical applications. The advantages of gold thin films (GTF) include flexibility, ease of manufacture, adhesion to polymer surfaces, chemical stability, good electrical conductivity,... 

Experimental parameters have direct influences on materials properties and therefore their applications. The effect of plasma power on the properties of cobalt oxide thin films, prepared using plasma-enhanced chemical vapor deposition technique, on stainless steel substrates have been addressed in this paper. The structural, morphological, and compositional properties of these films were investigated by means of X-ray diffraction (XRD), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS) technique. The XRD patterns demonstrated the growth of polycrystalline Co3O4 thin film with a cubic spinel structure such that the intensity of (511) and (311) peaks increase as the... 

The principal objective involved in this research is to explore the mechanical behaviour of the binder using different mineral fillers such as stone dust (SD), brick dust (BD) and fly ash Class F (FA). Currently, a large quantity of roads is being constructed under the China-Pakistan Economic Corridor (CPEC) project. It is a major concern for quality of road to with stand heavy loads. For the investigation of the quality of roads, it is mandatory to evaluate the behaviour of mineral fillers addition in asphalt mastic. Fatigue cracking, thermal cracking and permanent deformation have been found a major common distress in the construction of road networks. In this study, the behaviour of... 

Nanostructured materials have attracted much attention in recent decades. Nowadays, there are numerous nanomaterials with several applications. The ultrasonic spray pyrolysis method is a cost-effective and adaptable technique based on an aerosol process for synthesizing nanoparticles and depositing thin films. The technique is capable of synthesizing metal, oxide, and composite nanomaterials with precisely controllable morphologies and chemical compositions using metal salts in aqueous solvents. More importantly, it is popular, as evident from the growing number of studies being conducted on the technique. Here, we review studies conducted on basic principles and applications of the...