Al-Azhar University, Faculty of Science (Boys)
Al-Azhar Bulletin of Science
1110-2535
2636-3305
25
Issue 2-B
2014
12
01
INFLUENCE OF POLYMER MOLECULAR WEIGHT ON LIGHT HARVESTING AND PERFORMANCE PARAMETERS OF THE ORGANIC SOLAR CELL
1
8
EN
Yasser
A. M.
Ismail
Departments of *Third Generation Solar Cells Laboratory, Physics, Faculty of Science, Al-Azhar University,
Assiut 71121, Egypt
Naoki
Kishi
Frontier Materials, Nagoya Institute of Technology, Nagoya 466-8555, Japan
Tetsuo
Soga
Frontier Materials, Nagoya Institute of Technology, Nagoya 466-8555, Japan
10.21608/absb.2014.22603
In the present article, we try to illustrate the behavior of the most common organic solar cell under the influence of polymer<br />molecular weight (in the range of 21,100-128,800 g/mol) on light harvesting and device performance parameters. The present<br />work demonstrates that, the molecular weight of donor polymer plays an important role in the light harvesting and performance<br />of a common-bulk heterojunction organic solar cell based on poly(3-hexylthiophene) (P3HT), as a donor polymer, and<br />[6,6]-phenyl-C61-butyric acid methyl ester (PCBM), as an acceptor. Through this study it is found that, the optical absorption<br />of P3HT:PCBM solar cell active layer is increased by increasing P3HT molecular weight. This may be as a result of increasing<br />active layer thickness and/or increasing backbone chain length of the polymer. In the same time, the absorption wavelength<br />range is narrowed and the absorption peak position is shifted towards lower wavelengths due to the entanglement in polymer<br />chains and reduction in polymer crystallinity at higher P3HT molecular weights. The external quantum efficiency (EQE) of the<br />investigated solar cells is increased by increasing P3HT molecular weight until the molecular weight that entangles the P3HT<br />chins and, therefore, restricts the charge carrier transfer and, then, reduces the EQE of the P3HT:PCBM solar cell. The performance<br />parameters of the P3HT:PCBM solar cell are improved by increasing P3HT molecular weights around 25,300 g/mol<br />and, after that, deteriorated at higher P3HT molecular weights up to 128,800 g/mol as a result of polymer chain entanglement<br />and reduction of the P3HT crystallinity. The present study shows that the best P3HT molecular weight is 25,300 g/mol, which<br />produces power conversion efficiency around 2.5 %.<br /><br />
Organic solar cells,Polymer molecular weight,Light harvesting,Device performance parameters
https://absb.journals.ekb.eg/article_22603.html
https://absb.journals.ekb.eg/article_22603_c4be7993fbfecd8b07aa5e14aa8a81d1.pdf
Al-Azhar University, Faculty of Science (Boys)
Al-Azhar Bulletin of Science
1110-2535
2636-3305
25
Issue 2-B
2014
12
01
VERIFICATION OF 235U, 238U BY MATHEMATICAL CALIBRATION CURVE FOR POINT SOURCES BY USING MONTE CARLO
9
14
EN
S. A.
Makhlouf
Faculty of Science, Al-Azhar University, Assiut, Egypt.
10.21608/absb.2014.22605
The calibration of -ray spectrometer was performed by means of a set of certified standard point sources of energies that<br />cover the energy range of interest. The value of the absolute full energy peak efficiency "ab “ could be found by measuring<br />“CR” experimentally and the use of the known value of “ A “. Also, it is possible to calculate “ab” for a certain source to<br />detector distances (D) by using Monte Carlo [MC] simulation method.<br />The obtained results indicated that the fitting is identical to the experimental curve and MCNP calculations, that is both<br />these two methods (experimental and MCNP) can be used to extend the curve to cover the high energy range. It is possible to<br />drop any line energy inside the used energy range to estimate the absolute full energy peak efficiency, (for example, the energies<br />185.7, 1001 and 1275 keV corresponding to the sources 235U, 238U and 22Na). However, it can be estimated by using<br />any method from the previous methods (experimental or MCNP in addition to the fitting equation).<br /><br />
point sources,experimental,fitting equation,MCNP,A mathematical calibration curve
https://absb.journals.ekb.eg/article_22605.html
https://absb.journals.ekb.eg/article_22605_d9090706354cbcfb53d943fe9607d49b.pdf
Al-Azhar University, Faculty of Science (Boys)
Al-Azhar Bulletin of Science
1110-2535
2636-3305
25
Issue 2-B
2014
12
01
SPECTRAL STUDY FOR THE EFFECT OF SOLVENT DIELECTRIC CONSTANT ON THE OPTICAL BAND GAP FOR (4-OXOTHIAZOLIDIN-2-YLIDENE) ACETONITRILE.
15
19
EN
M.
Ibrahim
Departments of Physics , Faculty of Science, Al Azhar University, Nasr city, Cairo 11884, Egypt.
G. A. M.
El Hag Ali
Chemistry, Faculty of Science, Al Azhar University, Nasr city, Cairo11884, Egypt
10.21608/absb.2014.22606
Heterocyclic compound of (4-oxothiazolidin-2-ylidene) acetonitrile was prepared in powder form. The crystalline<br />nature of the prepared sample was checked by X- ray diffraction (XRD). IR absorption spectra were recorded on a<br />Shimadzu 440 infrared spectrophotometer (cm-1) using the KBr technique (Shimadzu, Japan). Reflection spectra<br />of the powder sample were obtained in the wavelength range (200-2500 nm) at room temperature using spectrophotometer.<br />Absorption and transmission spectra of the prepared sample were obtained in different solvents in<br />the wavelength range (190-1100nm).The solvent used are acetone, dimethyformamid (D.M.F.) and glycerol. The<br />measurements were carried out at room temperature using (JENWAY 6405 UV/VIS) spectrophotometer. The optical<br />energy gap which is the difference between lowest unoccupied molecular orbital (LUMO) and highest occupied<br />molecular orbital (HOMO) was estimated. The effect of the solvent dielectric constant on optical band gap was<br />discussed.
Optical band gap,FT-IR absorption and X-ray diffraction
https://absb.journals.ekb.eg/article_22606.html
https://absb.journals.ekb.eg/article_22606_7878a43a0ead770599f903da09607fd6.pdf
Al-Azhar University, Faculty of Science (Boys)
Al-Azhar Bulletin of Science
1110-2535
2636-3305
25
Issue 2-B
2014
12
01
THE LTE SOLAR ABUNDANCE OF NEODYMIUM
1
6
EN
Abdelkawy
A.G.A.
Department of Astronomy and Meteorology, Faculty of Science, Al-AzharUniversity, Cairo, Egypt
Shaltout
A.M.K.
Department of Astronomy and Meteorology, Faculty of Science, Al-AzharUniversity, Cairo, Egypt
Beheary
M.M.
Department of Astronomy and Meteorology, Faculty of Science, Al-AzharUniversity, Cairo, Egypt
Bakry
A.
Department of Astronomy and Meteorology, Faculty of Science, Al-AzharUniversity, Cairo, Egypt
10.21608/absb.2014.22669
We study the solar photospheric abundance of singly ionized neodymium (Nd II) using high resolution spectroscopic data<br />obtained by Fourier transform spectrograph (FTS). Based on the Local Thermodynamical Equilibrium (LTE) assumption,<br />a new value of Nd abundance is derived. We succeed to select of 51 solar Nd II lines with accurate transition probabilities<br />measured experimentally by Den Hartog et al. (2003) and with accurate damping parameters are determined from literature.<br />Relying on atomic data of Opacity Distribution Function (ODF), we construct theoretical photospheric solar model.The mean<br />solar photospheric abundance obtained from all 51Nd II lines is log εNd= , which is mostly similar to the meteoric<br />value.
atomic data-Sun,abundances-Sun,photosphere
https://absb.journals.ekb.eg/article_22669.html
https://absb.journals.ekb.eg/article_22669_b4c829a689089564e6b697d5ad3d2046.pdf
Al-Azhar University, Faculty of Science (Boys)
Al-Azhar Bulletin of Science
1110-2535
2636-3305
25
Issue 2-B
2014
12
01
Perturbation effect on ground tracks of Molniya satellite orbits
13
20
EN
Awad
M.E.
Faculty of Science - Cairo University, Egypt
Hassan
I.A.
Faculty of Science - Cairo University, Egypt
Dewdar
H.R.
Faculty of Science - Cairo University, Egypt
Tealib
S.K.
Faculty of Science - Cairo University, Egypt.
10.21608/absb.2014.22671
The main concern in the present research work is to define the basic requirements study of many<br />perturbations forces that affect ground tracks of Molniya satellite orbits.<br />In this we are going to design a mathematical model to calculate the footprint of any satellite taking<br />into account the effect of disturbing forces (oblatness and solar radiation pressure) in order to get the<br />most accurate sub-satellite point, matlab language is used to design program to calculate the<br />mathematical models of footprint satellites with numerical application of some different Molniya<br />satellites orbit.
Artificial Satellites,Kozai's method,oblateness,solar radiation pressure,ground Track,Longitude,Latitude
https://absb.journals.ekb.eg/article_22671.html
https://absb.journals.ekb.eg/article_22671_8392de290c94eab86d796b6158a545b1.pdf