INFLUENCE OF POLYMER MOLECULAR WEIGHT ON LIGHT HARVESTING AND PERFORMANCE PARAMETERS OF THE ORGANIC SOLAR CELL
Yasser
Ismail
Departments of *Third Generation Solar Cells Laboratory, Physics, Faculty of Science, Al-Azhar University,
Assiut 71121, Egypt
author
Naoki
Kishi
Frontier Materials, Nagoya Institute of Technology, Nagoya 466-8555, Japan
author
Tetsuo
Soga
Frontier Materials, Nagoya Institute of Technology, Nagoya 466-8555, Japan
author
text
article
2014
eng
In the present article, we try to illustrate the behavior of the most common organic solar cell under the influence of polymermolecular weight (in the range of 21,100-128,800 g/mol) on light harvesting and device performance parameters. The presentwork demonstrates that, the molecular weight of donor polymer plays an important role in the light harvesting and performanceof a common-bulk heterojunction organic solar cell based on poly(3-hexylthiophene) (P3HT), as a donor polymer, and[6,6]-phenyl-C61-butyric acid methyl ester (PCBM), as an acceptor. Through this study it is found that, the optical absorptionof P3HT:PCBM solar cell active layer is increased by increasing P3HT molecular weight. This may be as a result of increasingactive layer thickness and/or increasing backbone chain length of the polymer. In the same time, the absorption wavelengthrange is narrowed and the absorption peak position is shifted towards lower wavelengths due to the entanglement in polymerchains and reduction in polymer crystallinity at higher P3HT molecular weights. The external quantum efficiency (EQE) of theinvestigated solar cells is increased by increasing P3HT molecular weight until the molecular weight that entangles the P3HTchins and, therefore, restricts the charge carrier transfer and, then, reduces the EQE of the P3HT:PCBM solar cell. The performanceparameters of the P3HT:PCBM solar cell are improved by increasing P3HT molecular weights around 25,300 g/moland, after that, deteriorated at higher P3HT molecular weights up to 128,800 g/mol as a result of polymer chain entanglementand reduction of the P3HT crystallinity. The present study shows that the best P3HT molecular weight is 25,300 g/mol, whichproduces power conversion efficiency around 2.5 %.
Al-Azhar Bulletin of Science
Al-Azhar University, Faculty of Science (Boys)
1110-2535
25
v.
Issue 2-B
no.
2014
1
8
https://absb.journals.ekb.eg/article_22603_c4be7993fbfecd8b07aa5e14aa8a81d1.pdf
dx.doi.org/10.21608/absb.2014.22603
VERIFICATION OF 235U, 238U BY MATHEMATICAL CALIBRATION CURVE FOR POINT SOURCES BY USING MONTE CARLO
S. A.
Makhlouf
Faculty of Science, Al-Azhar University, Assiut, Egypt.
author
text
article
2014
eng
The calibration of -ray spectrometer was performed by means of a set of certified standard point sources of energies thatcover the energy range of interest. The value of the absolute full energy peak efficiency "ab “ could be found by measuring“CR” experimentally and the use of the known value of “ A “. Also, it is possible to calculate “ab” for a certain source todetector distances (D) by using Monte Carlo [MC] simulation method.The obtained results indicated that the fitting is identical to the experimental curve and MCNP calculations, that is boththese two methods (experimental and MCNP) can be used to extend the curve to cover the high energy range. It is possible todrop any line energy inside the used energy range to estimate the absolute full energy peak efficiency, (for example, the energies185.7, 1001 and 1275 keV corresponding to the sources 235U, 238U and 22Na). However, it can be estimated by usingany method from the previous methods (experimental or MCNP in addition to the fitting equation).
Al-Azhar Bulletin of Science
Al-Azhar University, Faculty of Science (Boys)
1110-2535
25
v.
Issue 2-B
no.
2014
9
14
https://absb.journals.ekb.eg/article_22605_d9090706354cbcfb53d943fe9607d49b.pdf
dx.doi.org/10.21608/absb.2014.22605
SPECTRAL STUDY FOR THE EFFECT OF SOLVENT DIELECTRIC CONSTANT ON THE OPTICAL BAND GAP FOR (4-OXOTHIAZOLIDIN-2-YLIDENE) ACETONITRILE.
M.
Ibrahim
Departments of Physics , Faculty of Science, Al Azhar University, Nasr city, Cairo 11884, Egypt.
author
G. A. M.
El Hag Ali
Chemistry, Faculty of Science, Al Azhar University, Nasr city, Cairo11884, Egypt
author
text
article
2014
eng
Heterocyclic compound of (4-oxothiazolidin-2-ylidene) acetonitrile was prepared in powder form. The crystallinenature of the prepared sample was checked by X- ray diffraction (XRD). IR absorption spectra were recorded on aShimadzu 440 infrared spectrophotometer (cm-1) using the KBr technique (Shimadzu, Japan). Reflection spectraof the powder sample were obtained in the wavelength range (200-2500 nm) at room temperature using spectrophotometer.Absorption and transmission spectra of the prepared sample were obtained in different solvents inthe wavelength range (190-1100nm).The solvent used are acetone, dimethyformamid (D.M.F.) and glycerol. Themeasurements were carried out at room temperature using (JENWAY 6405 UV/VIS) spectrophotometer. The opticalenergy gap which is the difference between lowest unoccupied molecular orbital (LUMO) and highest occupiedmolecular orbital (HOMO) was estimated. The effect of the solvent dielectric constant on optical band gap wasdiscussed.
Al-Azhar Bulletin of Science
Al-Azhar University, Faculty of Science (Boys)
1110-2535
25
v.
Issue 2-B
no.
2014
15
19
https://absb.journals.ekb.eg/article_22606_7878a43a0ead770599f903da09607fd6.pdf
dx.doi.org/10.21608/absb.2014.22606
THE LTE SOLAR ABUNDANCE OF NEODYMIUM
Abdelkawy
A.G.A.
Department of Astronomy and Meteorology, Faculty of Science, Al-AzharUniversity, Cairo, Egypt
author
Shaltout
A.M.K.
Department of Astronomy and Meteorology, Faculty of Science, Al-AzharUniversity, Cairo, Egypt
author
Beheary
M.M.
Department of Astronomy and Meteorology, Faculty of Science, Al-AzharUniversity, Cairo, Egypt
author
Bakry
A.
Department of Astronomy and Meteorology, Faculty of Science, Al-AzharUniversity, Cairo, Egypt
author
text
article
2014
eng
We study the solar photospheric abundance of singly ionized neodymium (Nd II) using high resolution spectroscopic dataobtained by Fourier transform spectrograph (FTS). Based on the Local Thermodynamical Equilibrium (LTE) assumption,a new value of Nd abundance is derived. We succeed to select of 51 solar Nd II lines with accurate transition probabilitiesmeasured experimentally by Den Hartog et al. (2003) and with accurate damping parameters are determined from literature.Relying on atomic data of Opacity Distribution Function (ODF), we construct theoretical photospheric solar model.The meansolar photospheric abundance obtained from all 51Nd II lines is log εNd= , which is mostly similar to the meteoricvalue.
Al-Azhar Bulletin of Science
Al-Azhar University, Faculty of Science (Boys)
1110-2535
25
v.
Issue 2-B
no.
2014
1
6
https://absb.journals.ekb.eg/article_22669_b4c829a689089564e6b697d5ad3d2046.pdf
dx.doi.org/10.21608/absb.2014.22669
Perturbation effect on ground tracks of Molniya satellite orbits
Awad
M.E.
Faculty of Science - Cairo University, Egypt
author
Hassan
I.A.
Faculty of Science - Cairo University, Egypt
author
Dewdar
H.R.
Faculty of Science - Cairo University, Egypt
author
Tealib
S.K.
Faculty of Science - Cairo University, Egypt.
author
text
article
2014
eng
The main concern in the present research work is to define the basic requirements study of manyperturbations forces that affect ground tracks of Molniya satellite orbits.In this we are going to design a mathematical model to calculate the footprint of any satellite takinginto account the effect of disturbing forces (oblatness and solar radiation pressure) in order to get themost accurate sub-satellite point, matlab language is used to design program to calculate themathematical models of footprint satellites with numerical application of some different Molniyasatellites orbit.
Al-Azhar Bulletin of Science
Al-Azhar University, Faculty of Science (Boys)
1110-2535
25
v.
Issue 2-B
no.
2014
13
20
https://absb.journals.ekb.eg/article_22671_8392de290c94eab86d796b6158a545b1.pdf
dx.doi.org/10.21608/absb.2014.22671