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Document Type |
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Thesis |
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Document Title |
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Semiconducting Properties of some Crystals from M2ІІІX3VІ Binary System الخصائص شبه الموصلة لبعض البلورات من النظام الثنائيM2ІІІX3VІ |
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Subject |
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Girls' College of Education in Jeddah |
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Document Language |
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Arabic |
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Abstract |
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Semiconductor compounds play an important role in technological development nowadays because of their attractive characteristics so they call the attention of many physicists to explore more and more of their hidden secrets. M2III X3VI semiconductor compounds find many application, and having promising properties.
-In2Se3 and Ga2Te3 belong to a group of materials that have been and still are the subject of much intensive investigation because of their interesting characteristics.
High efficiency, low cost, local design constructed in our laboratory for crystal growth from melt based on Bridgman technique. This special design was used for grown -In2Se3 and Ga2Te3 single crystal. The product ingots were identified with x-ray analysis.
The obtained specimens were prepared with the required dimension for different measurements.
The results of the present investigations can be summarized as follow :-
1- Electrical conductivity and Hall coefficient.
An investigation has been carried out on the influence of temperature on the electrical conductivity and Hall phenomenon in a wild range of temperature under vacuum with the aid of pyrex glass cryostat designed for this purpose. The energy gap, the depth of the impurity level was checked. The Hall mobility and the carrier concentration were determined. The scattering mechanism was also detected and discussed.
2- Thermoelectric power (TEP)
This phenomenon was investigated by employing the differential method in a wide range of temperature. Thermoelectric power was checked under vacuum , using a brass working chamber.
Many physical parameters were estimated such as : effective masses diffusion coefficients. Relaxation times and diffusion length for both types of the carriers. Also the efficiency of the thermoelectric elements was evaluated.
3- Switching effect
The two specimens exhibit memory switching of the CCNR with S-shape. The phenomenon in our samples is very sensitive to the temperature, intensity of light , and sample thickness. The switching parameters ( ith , Vth , Pth , Eth , ih , Vh , Roff , Ron ) are checked under the influence of the different factors of the ambient conditions .
This mode of investigation (crystal growth and studying the transport properties in addition to switch phenomena) is the ideal way for finding out the possibility of making applications for these semiconductor compounds, especially in the field of energy conversion , devices , and electronic engineering. |
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Supervisor |
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Prof. Dr. Nagat Tawfeek Abbas |
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Thesis Type |
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Doctorate Thesis |
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Publishing Year |
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1430 AH
2009 AD |
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Added Date |
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Wednesday, December 30, 2009 |
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Researchers
| عفاف محمد بابعير | Babaier, Afaf M. | Researcher | Doctorate | |
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