Document Details
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Document Type |
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Thesis |
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Document Title |
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Preparation and Study the Characteristic Features of some Chalcogenides from the group A^3 B^3 C_2^6semiconductor Compounds تحضیر ودراسة الملامح الممیزة لبعض مركبات أشباه الموصلات الشالكوجنیدیة من المجموعةA^3 B^3 C_2^6 |
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Document Language |
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Arabic |
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Abstract |
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There is an increasing interest in ternary compound semiconductors
with the general formula III-III-VI2 owing to their attractive physical
properties; anisotropic, quasi-two-dimensional structure and unusual optical
and photoelectric characteristics.
AIIIBIIIC2
VI compounds as a collective group of materials have been and
still the subject of much intensive investigation. In the last few years
widespread attention has been paid to the semiconductors of the ternary
chalcogenides compound with the formula ABX2 (A,B represents metal
atoms-X represents chalcogen atoms). These compounds recently held the
attention of many physicists.
The compounds GaInSe2 and GaInTe2 has not yet been studied in
sufficient details . Nevertheless to our best knowledge relatively good data
exist for these semiconductor compounds GaInSe2 and GaInTe2. In view of the
scarcity of the data on the properties of these compounds. The objective of this
work gives the results of the experimental studying of electrical conductivity,
Hall effect and thermoelectric power, as well as switching phenomenon. The
aim of this work is to throw some light on the actual behavior of this two
compounds and reveal the contradiction of the previous results. The main
characteristic parameters of the crystals can be evaluated from the
experimental data.
High efficiency, low cost, local design was used for grown GaInSe2 and
GaInTe2 single crystal. The product ingots were identified with x-ray and
DTA analysis.
The results of the present investigation can be summarized as follow:
• Electrical conductivity and Hall effect
1. For GaInSe2 compound
Electrical conductivity and Hall effect was measured at the same time in
the temperature range extends from 203K to 443 K. The energy gap has been
Abstract
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found to be ΔEg= 1.8 eV, whereas the ionization energy has the value ΔEa=
0.15 eV. The sample under test has p-type conductivity. The variation of the
Hall mobility as well as the carrier concentration with temperature was
investigated. The scattering mechanism of the carrier in the whole
temperature range of investigation was checked.
2. For GaInTe2 compound
The effect of temperature on the electrical conductivity and Hall effect
was studied in the temperature range 173K to 473 K. The crystals obtained
had p-type conductivity with a hole concentration of 6.44 x 109 cm-3 at
room temperature. The energy gap as well as the ionization energy was
calculated.
Conductivity and Hall mobility at 300K were evaluated. The behavleior
of temperature dependence of Hall mobility was discussed.
• Thermoelectric power (TEP)
1. For GaInSe2 compound
The investigation covers a temperature range from 258 K to 495 K. The
values of thermoelectric power of GaInSe2 in conjunction with the previously
obtained data were used to calculate some important parameters.
Many physical parameters were estimated such as n , p , , , Dn ,
Dp , τn , τp , Ln and Lp. Also the figure of merit for GaInSe2 was evaluated.
2. For GaInTe2 compound
The thermoelectric power of GaInTe2 was investigated in the temperature
range from 258 K to 441 K.
The combination of the electrical and thermal measurements in the
present investigation makes it possible to find various physical parameters
such as mobilities, effective mass, relaxation times, diffusion coefficients and
diffusion lengths both for majority and for minority carries.
• Switching phenomenon
1. For GaInSe2 compound
The sample under test exhibit memory switching of the CCNR with
S-shape. The switching phenomenon in our sample is very sensitive to
temperature, light intensity and sample thickness. The switching parameters
(ith , Vth , ih , Vh , Pth , Eth , Roff and Ron) are checked under the influence of
the different factor of the ambient condition.
mn
p m
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2. For GaInTe2 compound
It has been found that GaInTe2 single crystal exhibit bistable or memory
switching. Memory switching effect measurements were performed with
single crystal of p – type GaInTe2.
The current – voltage characteristics is symmetrical with respect to the reverse
of the applied voltage and current The switching phenomenon were checked
under the influence of different factors of the ambient condition. The results
strongly indicated that the phenomenon in our sample is very sensitive to
temperature, light intensity and sample thickness.
This mode of investigation (crystal growth and studying the transport
properties in addition to switching phenomena) is the ideal way for finding
out the possibility of making application for these compound, especially in
the field of energy conversion , devices and electronic engineering |
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Supervisor |
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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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1433 AH
2012 AD |
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Number Of Pages |
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277 |
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Added Date |
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Wednesday, March 5, 2014 |
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Researchers
| حليمة ابراهيم السعيدي | El-Saeedy, Halemah Ibrahim | Investigator | Doctorate | |
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