Fabrication and Optimization of Perovskite Solar
Cell Using Two-Step Sequential Deposition
Method
R.
Sedighi
Institute for Nanoscience and Nanotechnology, Sharif University of Technology, Tehran .
author
F.
Tajabadi
Materials and Energy Research Center, Department of Nanotechnology and Advanced materials, Karaj .
author
N
. Taghavinia
Institute for Nanoscience and Nanotechnology, Sharif University of Technology, Tehran.
author
text
article
2016
per
Light-energy conversion by photoelectrochemical cells has been extensively studied in the past 50 years using various combinations of semiconductors. Organic–inorganic perovskites have recently attracted increasing attention as light absorber. A direct band gap, strong light absorption, and high carrier mobility make them excellent absorber in solar cells. The morphology, stoichiometry and crystallinity of perovskites have significant effect on the device performance significantly, then deposition techniques are critical to achieve high efficiency solar cells. Efficiency of perovskite solar cells improve from 9 to 15 in two years due to change of deposition method. In this research, the two step technique was employed for the deposition of perovskite films. Different parameters of this method such as TiO2 thickness, concentration of the CH3NH3I solution and dipping time in the CH3NH3I solution were optimized. Finally, in optimized condition, we obtained a power conversion efficiency of 11.9.
Nanoscale
انجمن نانوفناوری ایران
2423-5628
3
v.
3
no.
2016
https://nanomeghyas.ir/article_46492_4010a002f844b0b30689b3466daa9172.pdf
Optimizing the Performance of 1D Photonic
Crystal Based Biosensors Containing Gradient
Refractive Index Materials
F.
Bayat
Photonics Group, Research Institute for Applied Physics and Astronomy University of Tabriz,
Tabriz
author
S.
Ahmadi-Kandjani
Photonics Group, Research Institute for Applied Physics and Astronomy University of Tabriz,
Tabriz
author
H.
Tajalli
Photonics Group, Research Institute for Applied Physics and Astronomy University of Tabriz,
Tabriz
author
text
article
2016
per
In this work, we have optimized the performance of the 1D photonic crystal based biosensor. The photonic crystal contains the layers A, B and F which are ZnSe, SiO2 and a microfluidic channel, respectively. Also, there is a radial gradient refractive index defect layer in the center of the structure. By irradiating a plane beam to the proposed structure, a ring-shaped intensity profile is achieved on the output plane of the structure. Any changed in the effective refractive index of the fluid inside of microfluidic channels can cause a change in the radius of the intensity ring. There are different parameters such as number and thickness of the layers and the rate of the refractive index variation in the D layer that can effect the sensitivity. Optimizing these parameters, it is possible to sense the refractive index changes of 10^-5 .
Nanoscale
انجمن نانوفناوری ایران
2423-5628
3
v.
3
no.
2016
https://nanomeghyas.ir/article_46493_0ee36e3d4b7679d74a39bff3b9560ffa.pdf
Tunable Nonlinear Optical Mesoscopic System
Containing Graphene, Optimization of Optical
Bistability in THz Frequency
A.
Sharif
Photnics Lab., School of Physics, Iran University of Science & Technology, Narmak, Tehran, Iran,
author
M.H.
Majles Ara
Photonics Lab., Kharazmi University, Department of Physics, Mofatteh, Tehran.
author
B.
Ghaffary
Photnics Lab., School of Physics, Iran University of Science & Technology, Narmak, Tehran, Iran
author
M.
Khhodavirdizadeh
Optics & Laser Engineering group, Urmia University of Technology, Band raod, Urmia.
author
text
article
2016
per
In this paper, a mesoscopic-scaled system is proposed based on the embedded graphene layers inside a dielectric medium in order to improve the presentation of optical bistability in THz range. It is firstly shown that the nonlinearity is considerably enhanced in comparison to the visible range. It is also shown that the nonlinear behavior can be increased by increasing the number of graphene layers. For the purpose of analyzing these issues, we use Boltzmann equation to describe the optical conductivity. Then, THz light wave is traced through the embedded graphene layers via Maxwell equations. This yields the optical bistability hysteresis. The results show that the optical bistability is enhanced with increasing the number of graphene layers. The important issue in THz range is the tunability of nonlinearity with an external bias voltage.
Nanoscale
انجمن نانوفناوری ایران
2423-5628
3
v.
3
no.
2016
https://nanomeghyas.ir/article_46494_28082b740d77291f39e13234707a916e.pdf
Fabrication and Characterization of
Semi-Transparent Hybrid Light Emitting Diode
with Inverted Structure
H.
Alehdaghi
Faculty of science, Hakim Sabzevari university, Sabzevar
author
M.
Shahraki
Departeman of chemistry, university of Sistan & baluchestan, Zahedan
author
H.
Heydari
Departman of chemistry, Razi university, Kermanshah
author
text
article
2016
per
In recent two decades, a large share of lighting research has been assigned to investigation on organic light emitting diodes OLEDs. The basic structure of OLEDs consist of an organic emissive layer and another layers as injection or transporting layers which can be organic or inoarganic. In this report, with varying of silver thickness which acts as anode layer we could fabricated a semi-transparent hybrid LED. The minimum thickness which OLED with structure of “ITO/ZnO/Cs2Co3/PDY/MoO3/Ag” emits light both side was about 30 nm. The optical transmittance analysis showed Ag layers with thickness lower than 20 nm has been grown in island mode. In thick Ag layers, atomic force microscopy demonstrated that roughness is increased as Ag thickness is increased. The maximum brightness for semi-transparent hybrid LED was about 2290 cd/m2 with current efficiency of about 1 cd/A.
Nanoscale
انجمن نانوفناوری ایران
2423-5628
3
v.
3
no.
2016
https://nanomeghyas.ir/article_46495_02d6c2ea5532581b5871b909d5fce58e.pdf
Study of Fabrication and the Effect of Mn
Substitution on Structural and Magnetic Properties
of MnxFe0.7-xZn0.3Fe2O4 Nanoparticles
R.
Baranifar
Department of Physics, Khuzestan Science and Research Branch, Islamic Azad University, Ahvaz, Iran.
author
M.
Niyaifar
Department of Physics, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran.
author
text
article
2016
per
In this researcher, the MnxFe0.7-xZn0.3Fe2O4 ferrite nanoparticles prepared by co-precipitation method. In these compositions the value of x varies from 0 to 0.7. Structural and magnetic properties of synthesized powder were characterized by X-ray diffraction XRD, Far-Infrared spectroscopy Far-FTIR, Transmission Electron Microscopy TEM and vibration sample magnetometer VSM. The XRD results show that all of the samples have single phase spinel structure. The average crystallite size estimated of about 12 to 7 nm, using Scherrer´s formula. The Far-FTIR measurements show, two frequency bonds within the rang 300 to 600 cm-1 indicate the presence of cation-anion interactions in the octahedral and tetrahedral sites, respectively.Also Transmission Electron Microscope images show particles size uniform distribution. The VSM results show that the saturation magnetization for all the samples decrease by increasing the manganese content.
Nanoscale
انجمن نانوفناوری ایران
2423-5628
3
v.
3
no.
2016
https://nanomeghyas.ir/article_46496_be074d303951e103e14691123a1ea4c5.pdf
Photoluminescence Properties of Cadmium
Tungstate Synthesized by Hydrothermal Method
M T.
Tourchi Moghadam
Department of Physics, Iran University of Science and Technology, Tehran.
author
M.
Babamoradi
Department of Physics, Iran University of Science and Technology, Tehran.
author
R.
Azimirad
Maleke-Ashtar University of Technology, Tehran.
author
text
article
2016
per
In this study, CdWO4 nanoparticles with acetate base synthesized by hydrothermal method and their photoluminescence emission spectra were investigated. The photoluminescence PL results show a peak at 460 nm which is in agreement with the results of cadmium tungstate synthesized by cadmium nitrate as the starting materials. The FTIR spectra confirm the Cd-O, W-O and O-W bands in the CdWO4 structure. The X-ray diffraction pattern confirms the formation of single phase of monoclinic wolframite structure. Image obtained by SEM shows that cadmium tungstate synthesized as nano particles and agglomeration of nanoparticles with particle sizes less than 100 nm. The results show that cadmium acetate as a precursor can be used as a cheaper material for synthesizing cadmium tungstate.
Nanoscale
انجمن نانوفناوری ایران
2423-5628
3
v.
3
no.
2016
https://nanomeghyas.ir/article_46497_b459571f2e5322c25159c653ab1ed5ba.pdf
Synthesis and Characterization of Nanostructured
Copper Sulfide Thin Films Prepared by Spray
Pyrolysis Method, a Study on the Effect of Copper
Containing Precursor
H.
Enayati Taloobaghi
Department of Physics, Shahrood University of Technology, Shahrood.
author
H.
Eshghi
Department of Physics, Shahrood University of Technology, Shahrood.
author
text
article
2016
per
In this research, three copper sulfide CuxS, x1.8-2 thin films with three copper-related precursors copper sulfate, copper chloride and copper acetate are prepared using spray pyrolysis method at 285oC on glass substrate and their physical properties are investigated. The FESEM images indicate the presence of nanostructures in the layers and XRD spectra show the formation of various structure, i.e. either polycrystalline and amorphous. In continue due to the special properties of samples transmittance and reflectance in sunlight controller application and filtering the unwanted and harmful wavelengths application, The effect of spray rates on the optical and electrical properties of one of this sample were studied.
Nanoscale
انجمن نانوفناوری ایران
2423-5628
3
v.
3
no.
2016
https://nanomeghyas.ir/article_46498_1ce7c5a9b7a40696c5e9a41a940899fa.pdf
Effect of Environmental Temperature on Carbon
Nanotube Diameter During Growth in Chemical
Vapor Deposition
H.
Akbarpoor Sani
Department of Physics, Faculty of Basic Sciences, Shahed University, Tehran.
author
M.
Saeidi
Department of Physics, Faculty of Basic Sciences, Shahed University, Tehran.
author
text
article
2016
per
In this paper, a new physical model is presented to describe the relation between carbon nanotube and catalytic nanoparticle diameter and environmental temperature. This relation is obtained by considering the rate of fenced surface of catalytic nanoparticle in nanotube, which leads to an appropriate formula. Obtained results of the formula show that the diameter of carbon nanotube is increased by increasing of temperature. This happens because catalyst particle has been grown, and carbon atoms which bond to catalyst during growth, will be bonded to the external catalyst atoms. So the nanotube diameter is increased. Furthermore, investigation of dependence of nanotubes diameter on catalyst type during growth shows that if thermal expansion coefficient of catalytic nanoparticle is decreased, the diameter of nanotube at each variation of temperature will be decreased.
Nanoscale
انجمن نانوفناوری ایران
2423-5628
3
v.
3
no.
2016
https://nanomeghyas.ir/article_46499_d9248e46fb57c61567a988c72eda7104.pdf