Document Details

Document Type : Thesis 
Document Title :
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
 
Document Language : Arabic 
Abstract : 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 Abstrac t ز 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 Abstrac t ح 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 
Supervisor : Nagat Tawfeek Abbas 
Thesis Type : Doctorate Thesis 
Publishing Year : 1433 AH
2012 AD
 
Number Of Pages : 277 
Added Date : Wednesday, March 5, 2014 

Researchers

Researcher Name (Arabic)Researcher Name (English)Researcher TypeDr GradeEmail
حليمة ابراهيم السعيديEl-Saeedy, Halemah IbrahimInvestigatorDoctorate 

Files

File NameTypeDescription
 36655.pdf pdf 

Back To Researches Page