synthesis and characterization of some ... ... ), stannous iodide (sni 2), stannic iodide (sni 4)...

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  • 1

    SYNTHESIS AND CHARACTERIZATION OF SOME HALIDES AND CHALCOGENIDE CRYSTALS USING SOL-GEL METHOD.

    BY

    OKPALA UCHECHUKWU V. PG/Ph.D/05/39463

    PRESENTED TO: DEPARTMENT OF PHYSICS AND ASTRONOMY, UNIVERSITY OF

    NIGERIA, NSUKKA (UNN).

    SUPERVISOR: PROF. (MRS.) R. U. OSUJI

    AUGUST, 2012.

  • i

    SYNTHESIS AND CHARACTERIZATION OF SOME HALIDES AND

    CHALCOGENIDE CRYSTALS USING SOL-GEL METHOD.

    BY

    OKPALA UCHECHUKWU V. PG/Ph.D/05/39463

    A Thesis submitted in partial fulfillment of the requirement for the award of the degree of Doctor of Philosophy (Ph.D) in the

    department of Physics and Astronomy, University of Nigeria, Nsukka.

    Supervisor: Prof. Mrs. R. U. Osuji.

    Professor of Physics, University of Nigeria, Nsukka.

    August, 2012.

  • ii

    Certification

    Mr. U.V. Okpala, a postgraduate student in the Department of Physics and Astronomy with registration number PG/Ph.D/05/39463 has satisfactorily completed the requirement for research work for the degree of Doctor of Philosophy (Ph.D) in Physics and Astronomy with emphasis on Solar Energy Physics. The work embodied in this thesis is original and has not been submitted in full or part thereof for any other diploma or degree or professional qualification of this or any other university. …………………………… ………………………….. Supervisor Head of Department Prof. Mrs. R. U. Osuji Prof. Mrs. R. U. Osuji

    Professor of Physics, Professor of Physics, University of Nigeria, University of Nigeria, Nsukka. Nsukka.

    ……………………………..

    External Examiner.

    Prof. B.N. Onwuagba Department of Physics

    Federal University of Technology Owerri

  • iii

    Dedication

    This work is dedicated to my wife, children, brothers and sisters for their immense contributions, support, patience and understanding in various aspects and to my beloved father and mother who longed to see me graduate but are no more.

  • iv

    Acknowledgement.

    I thank and praise Almighty God who made it possible for me to

    see the end of this work in spite of all odds from high and low places. I

    wish to sincerely thank my able supervisor, Prof. Mrs. R.U. Osuji for her

    understanding, support and encouragements. My resounding gratitude

    goes to Dr. F.I. Ezema and Prof. J.O.Urama for their wonderful supports.

    Finally, I wish to thank all who have contributed in one way or the

    other to the success of this work.

  • v

    Table of Content.

    Title Page - - - - - - - - - - - i Dedication – - - - - - - - - - - ii Acknowledgement – - - - - - - - - iii Table of Contents -- - - - - - - - - iv List of Table - - - - - - - - - vii List of Figure - - - - - - - - - viii Abstract – - - - - -- - - - - ix Chapter One 1.1 Introduction - - - - - - - -- - - 1

    1.2 Halides and Chalcogenide Crystals - - - - - - 2

    1.3 Impurities of Locally Produced Materials (Bamboo, Raffia and Potash)- - 3

    1.4 Purpose of Study - - - - - - - - 5

    1.5 Scope of Study -- - -- - - --- - - - 6

    Chapter Two 2.1 Introduction - - - - - - - - - - 7 2.2 Vapour phased Deposition - - - - - - - 7 2.3 Properties of Thin Film/ Liquid Based Deposition Techniques - - 10 2.4 Characterization of Semiconductors - - - - - - 20 2.4.2 Optical Characterization -- - - - - - 21 2.4.2a Absorbance - - - - - - - - - 22 2.4.2b Transmittance - - - - - - - - - 22 2.4.2c Absorption Coefficient (a) - - - - - - - 22 2.4.2d Optical Constants n and k, Dielectric Constant e, and Optical (σop) - 23 2.4.2e Band gap - - - - - - - - - 24 2.4.3 Photoluminescence (pl) Spectroscopy--- - - - - - 25 2.4.4 Raman Spectroscopy - - - - - - - 25 2.4.5Ellipsometry- - - - - - - - - - 26 2.4.6 Optical Modulation Technique- - - - - - - 26 2.4.7 Microscopic Technique - - - - - - - 26 2.4.7a Optical Microscopy - - - - - - -- - 27 2.4.7b Electron Beam Techniques - - - - -- - 27 2.4.7bi Scanning Electron Microscopy (SEM)- - - - - - 27 2.4.7bii Transmission Electron Microscopy (TEM)- - - - - 27 2.4.7c. Scanning Probe Microscopy (SPM).- - - - - - 28 2.4.8. Structural Analysis- -- - -- - - - - - 28 2.4.8a. X-Ray Diffraction (XRD)- - - - - - - - 28 2.4.9. Structural Analysis of Surfaces- - - - - - - 29 2.5.1. Surface Analysis Methods- - - - - - - - 30 2.5.1a. Auger Electron Spectroscopy (AES)- - - - - - 30 2.5.1b. X-ray Photoelectron Spectroscopy (XPS)- - - - - 31 2.5.1c. Ion Beam Techniques- - - - - - - - 31 2.5.1d. Rutherford Backscattering Spectrometry (RBS)- -- - - 31

  • vi

    2.6.1. Fourier Transform Infrared Spectroscopy (FTIR)- - - - 32 2.6.2. Electrical Characterization - - - - - -- - 33 2.6.2a. Resistivity and the Hall Effect- - - - - - - 33 2.6.2b. Capacitance-Voltage Measurements- - - - - - 34 2.6.2c. Photoconductivity- - - - - - - - - 34 Chapter Three 3.1 Introduction - - - - - - - - - - 35 3.2 Experimental details- - - - - - - - - 35 3.2.1 Growth of Lead Chloride (PbCl2)- - - - - - - 36 3.2.2 Growth Stannous and Stannous Iodide in Silica Gel (SnI2, SnI4).-- - 37 3.2.3 Growth of Potassium Perchlorate Crystal in Silica Gel (KClO4)- - 38 3.2.4 Growth of Cadmium Sulphide (CdS)- - - - - - 39 3.3 Drying- - - - - - - - - - - 40 Chapter Four

    4.0 Result and Discussions-- - - - - - - - 42 4.1 Optical Analysis Result- - - - - - - - 42 4.2 Optical Structural Analysis Result -- - - - - 42 4.1a Optical result for lead Chloride (PbCl2)- - - - - - 42 4.1b Optical result for Potassium Perchlorate (KClO4)- - - - - 49 4.1c Optical Results for Stannous Iodide (Snl2)- - - - - - 55 4.1d Optical Results for Stannic Iodide (Snl4)- - - - - - 62 4.1e Optical Results for Cadmium Sulfide (CdS) - - - - 68 4.1f Optical Results for Local Impurity- - - - - - - 74 4.2 Structural Properties Results - - - - - - - 81 4.3 Fourier Transform Infra red (FTIR)- - - - - - - 105 Chapter Five 5.1 Summary, Conclusion and Recommendation - - - - 114 5.2 Summary of Work- - - - - - - - - 114 5.2a Lead Chloride (PbCl2)- - - - - - - - 114 5.2b. Potassium Perchlorate (KClO4).- - - - - - - 116 5.2c. Stannous and Stannic Iodides (SnI2)- - - - - - 116 5.2d. Stannic iodide (SnI4)- - - - - - - - - 117 5.2e. Cadmium Sulphide (CdS)- - - - - - - - 117 5.2f. Local Impurities (Bamboo, Potash and Raffia) - - - - - 118 5.3. Conclusion- - - - - - - - - - 118 5.4. Suggestions and Recommendations- - - - -- - 119 References- - - - - - - - - - - 121 Appendix 1: List of Grown Samples - - - - - - - 130 Appendix 2: List of Abbreviations - - - - - - - 131 Appendix 3: Graphs of FTIR - - - - - - - - 131

  • vii

    List of Tables

    Table 3.1: The Concentration, pH and amount of the

    Precursors for the Growth of PbCl2 Crystal.-- - - 36

    Table 3.2: The Concentration, pH and amount of Precursors

    Used for the Growth of KClO4 Crystal. - - - - 37

    Table 3.3: The Concentration, pH and amount of Precursors

    for the Growth of SnI2 Crystal. - - - - - 38

    Table 3.4: The Concentration, pH and amount of the Precursors

    used for the Growth of SnI4 Crystal.- - - - 39

    Table 3.5: Concentration, pH and amount of the Precursors

    used for the Growth of CdS Crystal.- - - - 40

    Table 3.6: Fourier Transform Infra Red Bond Structure Comparison - 106

    Table 3.7: Fourier Transform Infra Red Bond Structure Comparison for

    Un-doped and Impurity Doped Potassium

    Perchlorate (KCl04) (CM -1).- - - - - 107

    Table 3.8: Fourier Transform Infra Red Bond Structure

    Comparison for Un-doped and Local Impurity

    Doped Stannous Iodide (SNI2) (CM -1).- - - - 108

    Table 3.9: Fourier Transform Infra Red Bond Structure

    Comparison for Un-Doped and Impurity Doped

    Stannic Iodide (SnI4) (CM -1).- - - - - 109

    Table 4.0: Fourier Transform Infra Red Bond Structure Comparison for

    Undoped and Local Impurity Doped Cadmium

    Sulphide (CdS ) (CM-1)- - - - - - 111

    Table 4.1: Fourier Transform Infra Red Bond Structure

    Comparison for local Impurities (Potash, Bamboo, Rafia)- 112

  • viii

    List of Plates

    Plate 1: Picture of the experimental set up - - - 155

    Plate 2: The researcher weighing the samples- - - 155

    Plate 3: Grown samples- - - - - - - 156

    Plate 4: Dried samples of SnI2, SnI4 and CdS- - - -156

    Plate 5: Dried samples of PbCl2 and KClO4- - - - 157

    Plate 6: Picture of all the dried samples- - - - -157

    Picture 7: The Researcher with the Analyst during XRD

    characterization @ CERD Ife. - - - - 158

  • ix

    Abstract In this research work, sol-gel technique was used to grow some crystals of halide and chalcogenide compounds. These grown crystals were doped with locally produced dopants from bamboo, raffia and potash to see how they can affect the optical and structural properties of the crystals. Dopant

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