Showing 8 results for Thin Film
F. Rahman, J. Podder, M. Ichimura,
Volume 5, Issue 2 (7-2011)
Abstract
Thin films of indium doped zinc sulfide (ZnS) for different indium (In) concentrations (x=0.0 - 0.8) were deposited onto glass substrate by spray pyrolysis method at 523K temperature. Aqueous solution of zinc acetate, indium chloride and thiorea were used to deposit the In-Zn-S film. The deposited thin films were characterized by Energy dispersive X-ray (EDX), Scanning electron microscopy (SEM), X-ray diffraction (XRD), and by UVvisible spectroscopy. The XRD spectra of In-Zn- S revealed both the amorphous and polycrystalline property for different In concentration. The EDX showed a well stoichiometric result of different compositions of In in ZnS thin films. The granularity of irregular shape is observed in In doped ZnS thin films surface by scanning electron microscope. From the absorbance and transmittance data it is observed that the band gap energy is decreased from 3.75eV to 3.1eV with the increase of In concentration in ZnS.
Hojjat Amrollahi Bioki, Mahmood Borhani Zarandi,
Volume 5, Issue 2 (7-2011)
Abstract
Zinc Sulfide (ZnS) thin films were deposited on glass substrates at the pressure of 10-6 mbar by thermal resistor evaporation technique. The effects of annealing on the structural, optical properties of ZnS films were studied. Crystalline ZnS films have been analyzed by X-ray diffraction. Only cubic phase with the preferred (111) plane was found in ZnS films. Optical characteristics were studied as a function of annealing temperature and thickness in air. The results show that the energy band gap was found to be about 3.5 eV. It was observed that the energy gap decreases with the increase in the film thickness and increases with the increase in the annealing temperature.
Dr. Abbas Behjat, Mehdi Dehghani, Fariba Tajabadi, Nima Taghavinia,
Volume 9, Issue 1 (1-2015)
Abstract
Planar superstrate CuInS2 (CIS) solar cell devices are fabricated using totally solution-processed deposition methods. A titanium dioxide blocking layer and an In2S3 buffer layer are deposited by the spray pyrolysis method. A CIS2 absorber layer is deposited by the spin coating method using CIS ink prepared by a 1-butylamine solvent-based solution at room temperature. To obtain optimum annealing temperature, these layers are first annealed at 150°C and then annealed at 210°C, 250°C and 350°C respectively. The optimum annealing temperature of the layer is found to be 250°C, where 23 mA current density and 505 mV open circuit voltage are measured for the best fabricated solar cell sample.
Seyed Mohammad Hosein Khalkhali, Dr. Mohammad Mehdi Tehranchi, Dr. Seyedeh Mehri Hamidi,
Volume 10, Issue 1 (4-2016)
Abstract
We examine the photo-assisted polarization loop in a BiFeO3 thin film under UV light illumination. BiFeO3 thin film prepared by pulsed laser deposition method onto the BaTiO3 thin film and the polarization behavior has been measured under poling voltage. Our results show the engineered polarization due to controllable schottky barrier under inverse poling voltage. This control on schottky barrier height and then polarization of thin film can be opened the new insight in the ferroelectric devices.
Nizar Shnan, Ahmed Kodeary, Saddam Haddawi, Neda Roostaei, Seyedeh Mehri Hamidi,
Volume 14, Issue 2 (12-2020)
Abstract
Silver nanowires are the favorable material in many applications based on their plasmonic double resonance in the visible region. In this paper, thin films of Poly-vinyl-pyrrolidone (PVP) doped with Silver nanowires (Ag NWs) in different concentrations have been prepared. The plasmonic imaging system using a high numerical aperture objective lens excite the Surface Plasmon in these structures. The hot spot results from reflected light intensity of surface plasmon resonance (SPR) proved that increasing of concentration of Silver nanowires yields to get better hot spot in plasmonic imaging systems by choosing the appropriate wavelength. These obtained results accompanying with third order nonlinear investigations show the ability of samples usage in thermoplasmonic applications.
Dr. Mojtaba Shahraki, Dr. Majid Ghadrdan,
Volume 15, Issue 1 (1-2021)
Abstract
In this paper, the optical properties of laterally oriented core-shell nanowire silicon solar cells (NWSCs) are optimized. The optimum structure consists of an array with non-uniform hexagonal nanowires (NWs). Each NW is constructed from an amorphous silicon layer sandwiched between two crystalline silicon layers. In order to improve the light absorption and short circuit current density (Jsc) of NWSC, a particle swarm optimization (PSO) algorithm is used to optimize the geometrical parameters of NWs. It is shown that the optimized structure has advantageous performance in terms of light absorption and Jsc. Finally, a multiple structure composed of two NWs with different morphologies and the optimized dimensions is proposed to utilize NWSCs better.
Miss Nasrin Sepahvand, Mr Mohsen Bahrami,
Volume 15, Issue 1 (1-2021)
Abstract
In this work, the effect of changing the dimensions of the layer structure on the collection of electrical charge carriers which been produced in the thin film composed of P3HT[1] and PCBM[2] that is between two electrodes, using the Monte Carlo numerical simulation with Bortez, Callus and Lebowitz algorithms, with checkered structure and different dimensions 60×15×5 sites, 60×30×5 sites, have been the conditions of the layers. At first, the average number of electrons and holes produced on the cathode and anode electrodes in two stages (simultaneous injection of excitons, without and with the presence of deep traps) was calculated and it was concluded that, by increasing layer width, the average number of electrical charge carriers collected on the electrodes has decreased, which has a direct impact on production of layer circuits and solar cell performance. Finally, the amount of external quantum efficiency of the layers was also calculated. In 60×15×5 sites layer, in two stages – without and with the presence of traps – the average value of external quantum efficiency 52.3% and 42.43% was obtained and in 60×30×5 sites layer, the value of 42.43% and 37.9% was calculated.
[1] Poly(3-hexylthiophene)
[2] Phenyl-C61-butyric acid methyl ester
Iman Rahmani, Majid Ghanaatshoar,
Volume 16, Issue 2 (7-2022)
Abstract
ta charset="UTF-8" >We investigate the Cu2FeSnS4 (CFTS) thin film. The raw materials of this thin film are copper, iron and tin, which are mixed in the form of tablets and then are deposited on a glass substrate through the process of pulsed laser deposition (PLD). The produced metallic thin films are then sulfurized to carry out the process of merging the element sulfur in the thin films and forming CFTS structure. We investigate the influence of sulfurization temperature and the laser pulse energy in the PLD process on the deposited CFTS thin films. The X-ray diffraction (XRD), Raman and UV-Vis analyses’ results show that by decrease in sulfurization temperature from 600 °C to 550 °C the crystal quality of the thin films is improved, which is realized by increase in volume and quality of the CFTS phase. On the other hand, the results confirm that the laser fluence is a decisive factor which should be taken into account to achieve an optimized structure.