Investigation of CdSexTe1-x II-VI Ternary Semiconductor Band Energy Gap

Abstract: CdSexTe1-x II-VI Ternary semiconductor is very important as an x of a constituent in the semiconductor is going to have significant changes in calculating Physical Property like Band Energy Gap. These Ternary Compounds can be derived from binary compounds CdSe and CdTe by replacing one half of the atoms in one sub lattice by lower valence atoms, the other half by higher valence atoms and maintaining average number of valence electrons per atom. The subscript X refers to the alloy content or concentration of the material, which describes proportion of the material added and replaced by alloy material. This paper represents the CdSexTe1-x II-VI Ternary Semiconductor Band Energy Gap values

Keywords: Band Energy Gap, Composition, Electro Negativity, Molecular weight, density, optical polarizability.

Introduction: 1) In this opening talk of CdSexTe1-x II-VI Ternary Semiconductor Band Energy Gap Electronegativity values of Ternary Semiconductors are denoted by symbols XM and XN and Band Energy Gap is denoted by Eg

2) Linus Pauling first proposed Electro Negativity in 1932 as a development of valence bond theory,[2] it has been shown to correlate with a number of other chemical properties.

3) The continuous variation of physical properties like Electro Negativity of ternary compounds with relative concentration of constituents is of utmost utility in development of solid-state technology.

4) In the present work, the solid solutions belonging to CdSexTe1-x II-VI Ternary Semiconductor Band Energy Gap have been investigated. In order to have better understanding of performance of these solid solutions for any particular application, it becomes quite necessary to work on the physical properties like Electro Negativity of these materials.

5) Recently no other class of material of semiconductors has attracted so much scientific and commercial attention like the II-VI Ternary compounds.

6) Doping of Se component in a Binary semiconductor like CdTe and changing the composition of do pant has actually resulted in lowering of Band Energy Gap.

7) Thus effect of do pant increases the conductivity and decreases the Band Energy Gap and finds extensive applications.

8) The present investigation relates Band Energy Gap and Electro Negativity with variation of composition for CdSexTe1-x II-VI Ternary Semiconductor.

9) The fair agreement between calculated and reported values of Band Energy Gaps of CdSe and CdTe Binary semiconductors give further extension of Band Energy Gaps for Ternary semiconductors.

10) The present work opens new line of approach to Band Energy Gap studies in CdSexTe1-x II-VI Ternary Semiconductor

Objective: The main Objective of this paper is to calculate CdSexTe1-x II-VI Ternary Semiconductor Band Energy Gap values

Purpose: The purpose of study is CdSexTe1-x II-VI Ternary Semiconductor Band Energy Gap and effect of concentration in Electro Negativity values of II-VI Ternary Semiconductors to represent additivity principle even in very low concentration range. This paper includes Electro Negativity values of II-VI ternary semiconductors and Band Energy Gap values in composition range (0 Theoretical Impact: Formula: Eg=[28.8/(2(XM-XN)2)1/4*(1-f12/1+2*f12)]POWER (XM/XN)2 Where:f12=[4pN/3]*[aM12*r12]/M12

Compound Cd Zn Te Hg Se S E.N value 1.69 1.65 2.1 2 2.55 2.58

X value 0 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5 1-x value 1 0.9 0.85 0.8 0.75 0.7 0.65 0.6 0.55 0.5

Compound CdSexTe1-x XM value 1.69 1.69 1.69 1.69 1.69 1.69 1.69 1.69 1.69 1.69 XN value 2.1 2.141171 2.162058 2.183149 2.204446 2.22595 2.247665 2.269591 2.291731 2.314087

XM/XN 0.804762 0.789288 0.781662 0.774111 0.766632 0.75923 0.751891 0.744627 0.737434 0.73031 (XM/XN)2 0.647642 0.622975 0.610996 0.599248 0.587725 0.57642 0.565341 0.55447 0.543809 0.533352

XM-XN -0.41 -0.451171 -0.47206 -0.49315 -0.51445 -0.53595 -0.55767 -0.57959 -0.60173 -0.62409

(XM-XN)2 0.1681 0.203555 0.222839 0.243196 0.264655 0.28724 0.31099 0.335926 0.362081 0.389485

2(XM-XN)2 1.123578 1.151533 1.167028 1.183612 1.201349 1.22031 1.240559 1.262187 1.285278 1.309926

(2(XM-XN)2)1/4 1.029558 1.035903 1.03937 1.043043 1.046929 1.05104 1.055369 1.059939 1.064754 1.069822

28.8/(2(XM-XN)2)1/4 27.97317 27.80183 27.70908 27.61151 27.50903 27.4016 27.28903 27.17137 27.0485 26.92036 M-VALUES 240.01 235.146 232.714 230.282 227.85 225.418 222.986 220.554 218.122 215.69 RO-VALUES 5.86 5.84 5.83 5.82 5.81 5.8 5.79 5.78 5.77 5.76 ALPHA-M 103.286 101.3429 100.3714 99.3998 98.42825 97.4567 96.48515 95.5136 94.54205 93.5705

ALPHA-M *RO 605.256 591.8425 585.1653 578.5068 571.8681 565.249 558.649 552.0686 545.5076 538.9661 ALPHA-M*RO/M 2.521795 2.516915 2.514525 2.512167 2.509845 2.50756 2.50531 2.5031 2.500929 2.4988

4*PI*N VALUES 75.64888 75.64888 75.64888 75.64888 75.64888 75.6489 75.64888 75.64888 75.64888 75.64888 10 POWER23 1.00E+23 1.00E+23 1.00E+23 1.00E+23 1.00E+23 1.00E+23 1.00E+23 1.00E+23 1.00E+23 1.00E+23 TOTAL 4*PI*N 7.56E+24 7.56E+24 7.56E+24 7.56E+24 7.56E+24 7.56E+24 7.56E+24 7.56E+24 7.56E+24 7.56E+24

4*PI*N/3 VALUES 2.52E+24 2.52E+24 2.52E+24 2.52E+24 2.52E+24 2.52E+24 2.52E+24 2.52E+24 2.52E+24 2.52E+24 (4PIN/3)*ALPHAM*RO/M 6.36E+24 6.35E+24 6.34E+24 6.33E+24 6.33E+24 6.3E+24 6.32E+24 6.31E+24 6.31E+24 6.3E+24

1-(4PIN/3)*ALPHAM*RO/M 6.36E+24 6.35E+24 6.34E+24 6.33E+24 6.33E+24 6.3E+24 6.32E+24 6.31E+24 6.31E+24 6.3E+24 1+2*(4PIN/3)*ALPHAM*RO/M 1.27E+25 1.27E+25 1.27E+25 1.27E+25 1.27E+25 1.3E+25 1.26E+25 1.26E+25 1.26E+25 1.26E+25

1-phi12/1+phi12 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 28.8/(2(XM-XN)2)1/4*(1-phi12/1+2*phi12) 13.98659 13.90092 13.85454 13.80575 13.75451 13.7008 13.64452 13.58568 13.52425 13.46018

Eg value 5.52091 5.153325 4.983203 4.82146 4.667594 4.52114 4.381653 4.248737 4.12201 4.00112

X value 0.55 0.6 0.65 0.7 0.75 0.8 0.85 0.9 0.95 1 1-x value 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 XM value 1.69 1.69 1.69 1.69 1.69 1.69 1.69 1.69 1.69 1.69 XN value 2.336661 2.359456 2.382472 2.405714 2.429181 2.452878 2.476806 2.500968 2.525365 2.55

XM/XN 0.723254 0.716267 0.709347 0.702494 0.695708 0.688986 0.68233 0.675738 0.66921 0.662745 (XM/XN)2 0.523097 0.513038 0.503173 0.493498 0.484009 0.474702 0.465575 0.456622 0.447842 0.439231 XM-XN -0.64666 -0.66946 -0.69247 -0.71571 -0.73918 -0.76288 -0.78681 -0.81097 -0.83536 -0.86

(XM-XN)2 0.418171 0.448171 0.479518 0.512246 0.546389 0.581983 0.619064 0.657669 0.697834 0.7396 2(XM-XN)2 1.336232 1.364309 1.394278 1.426269 1.460426 1.496906 1.535879 1.577531 1.622068 1.669713 (2(XM-XN)2)1/4 1.075154 1.080757 1.086644 1.092824 1.099309 1.106111 1.113241 1.120713 1.128541 1.136738

28.8/(2(XM-XN)2)1/4 26.78687 26.64798 26.50362 26.35373 26.19827 26.03718 25.87041 25.69792 25.51968 25.33565

M-VALUES 213.258 210.826 208.394 205.962 203.53 201.098 198.666 196.234 193.802 191.37 RO-VALUES ALPHA-M 92.59895 91.6274 90.65559 89.6843 88.71275 87.7412 86.76965 85.7981 84.82655 83.855 ALPHA-M *RO 92.59895 91.6274 90.65559 89.6843 88.71275 87.7412 86.76965 85.7981 84.82655 83.855

ALPHA-M*RO/M 0.434211 0.434611 0.43502 0.435441 0.435871 0.436311 0.436761 0.437223 0.437697 0.438183

4*PI*N VALUES 75.64888 75.64888 75.64888 75.64888 75.64888 75.64888 75.64888 75.64888 75.64888 75.64888 10 POWER23 1.00E+23 1.00E+23 1.00E+23 1.00E+23 1.00E+23 1.00E+23 1.00E+23 1.00E+23 1.00E+23 1.00E+23 TOTAL 4*PI*N 7.56E+24 7.56E+24 7.56E+24 7.56E+24 7.56E+24 7.56E+24 7.56E+24 7.56E+24 7.56E+24 7.56E+24 4*PI*N/3 VALUES 2.52E+24 2.52E+24 2.52E+24 2.52E+24 2.52E+24 2.52E+24 2.52E+24 2.52E+24 2.52E+24 2.52E+24

(4PIN/3)*ALPHAM*RO/M 1.09E+24 1.1E+24 1.1E+24 1.1E+24 1.1E+24 1.1E+24 1.1E+24 1.1E+24 1.1E+24 1.1E+24 1-(4PIN/3)*ALPHAM*RO/M 1.09E+24 1.1E+24 1.1E+24 1.1E+24 1.1E+24 1.1E+24 1.1E+24 1.1E+24 1.1E+24 1.1E+24 1+2*(4PIN/3)*ALPHAM*RO/M 2.19E+24 2.19E+24 2.19E+24 2.2E+24 2.2E+24 2.2E+24 2.2E+24 2.21E+24 2.21E+24 2.21E+24

1-phi12/1+phi12 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 28.8/(2(XM-XN)2)1/4*(1-phi12/1+2*phi12) 13.39344 13.32399 13.25181 13.17687 13.09913 13.01859 12.9352 12.84896 12.75984 12.66782

Eg value 3.885736 3.775552 3.670278 3.569647 3.473406 3.381319 3.293165 3.208736 3.127838 3.050289

Doping of Se component in a Binary semiconductor like CdTe and changing the composition of do pant has actually resulted in decrease of Band Energy Gap for good Electrical conduction.

Future Plans: 1) Current data set of Electro Negativity values of CdSexTe1-x II-VI Ternary Semiconductors and Band Energy Gap values include the most recently developed methods and basis sets are continuing. The data is also being mined to reveal problems with existing theories and used to indicate where additional research needs to be done in future.

2) The technological importance of the ternary semiconductor alloy systems investigated makes an understanding of the phenomena of alloy broadening necessary, as it may be important in affecting semiconductor device performance.

Conclusion: 1) This paper needs to be addressed theoretically so that a fundamental understanding of the physics involved in such phenomenon can be obtained in spite of the importance of ternary alloys for device applications.

2) Limited theoretical work on Electro Negativity values and Band Energy Gap of CdSexTe1-x II-VI Ternary Semiconductors with in the Composition range of (0 3) Our results regarding the Electro Negativity values and Band Energy Gap of II-VI Ternary Semiconductors are found to be in reasonable agreement with the experimental data

Results and Discussion: Electro Negativity values of Ternary Semiconductors are used in calculation of Band Energy Gaps and Refractive indices of Ternary Semiconductors and Band Energy Gap is used for Electrical conduction of semiconductors. This phenomenon is used in Band Gap Engineering.

Acknowledgments. – This review has benefited from V.R Murthy, K.C Sathyalatha contribution who carried out the calculation of physical properties for several ternary compounds with additivity principle. It is a pleasure to acknowledge several fruitful discussions with V.R Murthy.

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