Sharif Digital Repository

In the last decade, the power conversion efficiency (PCE) of solution-processed perovskite solar cells (PSCs) in the lab-scale has reached an incredible level of 25.5%. Generally, PSCs are composed of a stack consisting of a perovskite thin-film sandwiched between an electron transporting layer (ETL) and a hole transporting layer (HTL). Although the quality of the ETL and HTL interfaces with the perovskite thin-film is important, the quality of the perovskite thin-film is also critical to achieving high-performance PSCs. Low-temperature deposition of organic-inorganic perovskite thin-films by simple solution processes is one of the significant advantages of PSCs compared to other... 

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... 

In this study, ZrO2 coatings with different thicknesses were grown by the electron beam evaporation technique. The crystalline structure was studied by XRD analysis which suggested the tetragonal and monoclinic phases for ZrO2 coatings. Additionally, the film thickness slightly enhanced the crystallinity. The surface morphology and fractal features were analyzed using Scanning Electron Microscopy (SEM). The surface statistical parameters and the fractal geometry were employed to analyze the impact of the coating thickness and homogeneity on the morphology of the films. The statistical processing and fractal dimension revealed variations in the morphology parameters due to the electron beam... 

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... 

Studies on copper zinc tin sulpher selenide (CZTSSe) thin-film material and its applications as a base material are intensively being researched since it is an earth-abundant, inexpensive, flexible, and interesting material for next-generation optoelectronic technologies. Apropos, this study explores and reports the synthesis of CZTSSe thin films and their key optoelectronics characteristics. The reported films are fabricated on a soda-lime glass substrate by using a physical vapor deposition technique, and then annealed from 250 to 450 °C. From the X-ray diffraction analysis, the structure of the as-deposited thin films is found to be amorphous in nature. Annealed thin films of CZTSSe... 

In this study, 490 nm thin tin selenide thin films were deposited by facile co-evaporation techniques using Sn and Se sources on a clean glass substrate. The thin films were annealed at moderate annealing temperature followed by characterization and analysis. The thin annealed films possess polycrystalline nature and orthorhombic structure with an average grain size of 130 nm. The band gap assessed from absorption spectra for the highly annealed sample was 1.52 eV. The resistivity and sheet resistance were measured with four-probe techniques and the sheet resistance was =1.362 × 104 ohm for the highly annealed film. © 2021 John Wiley & Sons Ltd  

Studies on copper zinc tin sulpher selenide (CZTSSe) thin-film material and its applications as a base material are intensively being researched since it is an earth-abundant, inexpensive, flexible, and interesting material for next-generation optoelectronic technologies. Apropos, this study explores and reports the synthesis of CZTSSe thin films and their key optoelectronics characteristics. The reported films are fabricated on a soda-lime glass substrate by using a physical vapor deposition technique, and then annealed from 250 to 450 °C. From the X-ray diffraction analysis, the structure of the as-deposited thin films is found to be amorphous in nature. Annealed thin films of CZTSSe... 

In this study, 490 nm thin tin selenide thin films were deposited by facile co-evaporation techniques using Sn and Se sources on a clean glass substrate. The thin films were annealed at moderate annealing temperature followed by characterization and analysis. The thin annealed films possess polycrystalline nature and orthorhombic structure with an average grain size of 130 nm. The band gap assessed from absorption spectra for the highly annealed sample was 1.52 eV. The resistivity and sheet resistance were measured with four-probe techniques and the sheet resistance was =1.362 × 104 ohm for the highly annealed film. © 2021 John Wiley & Sons Ltd  

Three-dimensional macroporous fluorine-doped tin oxide (p-FTO) films were successfully deposited using commercial ink of FTO powder and SnCl2 salt via Dr. Blade method. Various features of p-FTO thin films were studied as a function of the ink composition and sintering temperature. The morphological studies corroborated formation of porous, uniform, and crack-free FTO films after annealing at 300 °C for 10 min in air. X-ray diffraction pattern demonstrated development of highly crystalline FTO films. The lowest sheet resistance of 47 Ω/□ was obtained for the p-FTO film with a thickness of 21 μm. The capacitance of thin p-FTO films was investigated using a three-electrode system and the... 

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... 

Herein, we deposited CuInSe2(CISe) thin films by using aqueous spray deposition method and post selenization process. The effect of different indium precursor salts including indium chloride, indium nitrate and indium acetate on the structural, morphological, optical and electrical properties of sprayed CISe layers has been studied by using x-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM-EDS), optical transmission (UV–Vis), Mott-Schottky analysis, I–V dark measurements. Although all the deposited thin films show a chalcopyrite tetragonal ordering structure of CISe, the crystallinity, morphology, and electrical characteristics are strongly influenced by the type of... 

This study represents the investigation of In2S3 thin films, which have been deposited with different Indium salts (Chloride, Acetate, and Nitrate) using the Chemical Spray Pyrolysis (CSP) method. The Mott-Schottky analysis has been used in case of studying the electrical properties of films such as conduction and valence band, carrier densities, Fermi level (Efn), flat band potential, and semiconductor type. In the next step, the Rb1MAFA perovskite solar cell has been simulated, and the results have been validated by the experimental data (with the least parameters for fitting). Finally, In2S3 layers have been inserted on the SnO2 layer to decrease the recombination rate and enhance the... 

This work focused on the spray pyrolysis deposition of Cu2SnS3 (CTS) thin films using a stable basic solution. The effect of the most important parameters including the substrate temperature and copper concentration on the structural, optical and electrical properties of as-deposited thin films was investigated. Qualified thin films with suitable microstructure and composition could be deposited at 370℃. XRD and Raman analysis while confirming the pure CTS film formation, show that as the Cu/Sn decreases, the crystal structure layers are changed from the tetragonal phase to the cubic phase mixed with Sn-rich phases. The optical study shows its band gap between 1.08 and 1.2 eV for different... 

The development of low cost and earth abundant electrocatalyst with high performance and desirable stability for hydrogen evolution reaction (HER) is an important issue in energy applications. Nickel sulfide thin films (NiSx) are formed on conductive nickel foam substrates via chemical vapor deposition (CVD) at 300 °C under low pressure condition. A single phase of Ni3S2 was produced by controlling the ratio of precursors. X-ray diffraction (XRD), field emission scanning electron spectroscopy (FESEM), X-ray photoelectron spectroscopy (XPS) and electrochemical measurements were conducted to characterize and compare properties of the samples. According to XRD and XPS data analysis, the growth... 

A practical coplanar Josephson junction left-handed transmission line based on a step-edge junction technique is proposed in high-temperature superconductor technology and analyzed by electromagnetic simulations. The layout is designed for monolayer Yttrium Barium Copper Oxide thin film fabrication process. The propagation stopbands are tunable by controlling bias currents of Josephson junction arrays acting as parallel inductors for unit cells of the transmission line. Unlike the reported designs, each unit cell of our left-handed transmission line is independently biasable due to dc isolation of the unit cells along the transmission line. Being individually biasable is practically... 

Three-dimensional macroporous fluorine-doped tin oxide (p-FTO) films were successfully deposited using commercial ink of FTO powder and SnCl2 salt via Dr. Blade method. Various features of p-FTO thin films were studied as a function of the ink composition and sintering temperature. The morphological studies corroborated formation of porous, uniform, and crack-free FTO films after annealing at 300 °C for 10 min in air. X-ray diffraction pattern demonstrated development of highly crystalline FTO films. The lowest sheet resistance of 47 Ω/□ was obtained for the p-FTO film with a thickness of 21 μm. The capacitance of thin p-FTO films was investigated using a three-electrode system and the... 

In present work, first, the water-stable metal–organic framework (MOF) nanocrystals, UiO-66-(F)4, were synthesized under green reaction condition and then some PES/PA thin-film nanocomposite (TFN) membranes were prepared using this synthesized nanocrystals (as modifier) and polyethersulfone (as the substrate). The obtained MOF and membranes were characterized by various characterization techniques such as FE-SEM, AFM, PXRD, contact angle measurements and FT-IR spectroscopy. Finally, the forward osmosis performance of the resultant membranes was evaluated by using different concentrations of NaCl as a draw solution and deionized water as a feed solution. Among all used membranes, the membrane... 

In this study, first, the UiO-66-NH2 metal-organic frameworks (MOFs) were modified with graphene quantum dots (GQDs) to facilitate the water attraction on MOF surface as well as improve their compatibility/affinity with the polyamide layer matrix of forward osmosis (FO) membranes. Next, to fabricate a new type of thin-film nanocomposite (TFN) membranes, the synthesized GQDs@UiO-66-NH2 composites are incorporated into the polyamide (PA) selective layer of FO membranes during the interfacial polymerization reaction of m-phenylenediamine (MPD) and trimesoyl chloride (TMC). The influence of the prepared fillers on the chemical structure, morphology, surface roughness and hydrophilicity of the PA... 

The thin-film of hierarchical rutile/anatase TiO2 nanorod/nanoleafs on fluorine-doped tin oxide glass was prepared via a facile method. For this purpose, the hydrothermal method was used for the synthesis of rutile-phase nanorods on the TiO2 seeded FTO, and aqueous chemistry was applied for growing anatase-phase nanoleafs on the nanorods. The structural, morphological, and optical properties of coating characterized, and the thin-film utilized as the photoelectrode for dye-sensitized solar cell. The energy conversion efficiency of the newly developed nanostructure was higher than that of TiO2 nanorod thin-film by 40%. This increase could be ascribed to: (1) superior specific surface area... 

Hierarchical TiO2 nanoleafed nanorod thin film was successfully synthesized on the fluorine doped tin oxide glass substrate. For this purpose, the nanorods were coated on the TiO2 seeded substrate via the hydrothermal method. Then, nanoleafs were grown on the nanorods by aqueous chemistry. Field emission scanning electron microscopy, energy dispersive spectroscopy, and Raman spectroscopy were utilized for thin film characterization. The results clarified that anatase-phase nanoleafs were uniformly grown on the rutile-phase nanorods in the TiO2 coating. The photocatalytic performance of the thin film was determined by photodegradation of anionic and cationic organic pollutants, and the...