Computational and theoretical studies on ZnS[x]Se[1-x] (0≤x≤1) / Ghassan H. Esa Al-Shabeeb

• Main Author: Al-Shabeeb, Ghassan H. Esa
• Format: Thesis
• Published: 2012
• Subjects: QC Physics
• Online Access: http://studentsrepo.um.edu.my/3874/1/1._Title_page%2C_abstract%2C_content.pdf; http://studentsrepo.um.edu.my/3874/2/CAHP_1%262_INTRO%2C_LIT_REVIEW.pdf; http://studentsrepo.um.edu.my/3874/3/CHAP_3_Results_for_ZnSxSe1%2Dx_(0_%E2%89%A4_x_%E2%89%A4_1)_from_CASTEP.pdf; http://studentsrepo.um.edu.my/3874/4/CHAP_4_Results_on_Energy_Gap_for_ZnSxSe1%2Dx_(0_%E2%89%A4_x_%E2%89%A4_1).pdf; http://studentsrepo.um.edu.my/3874/5/CHAP_5_Results_on_Energy_Gap_for_ZnSxSe1%2Dx.pdf; http://studentsrepo.um.edu.my/3874/6/CHAP_6_Results_on_the_Density_of_States_for_ZnSxSe1%2Dx.pdf; http://studentsrepo.um.edu.my/3874/7/CHAP_7%268_DISCUSSION_%26_RECOMMENDATIONS.pdf; http://studentsrepo.um.edu.my/3874/8/REFERENCES.pdf; http://studentsrepo.um.edu.my/3874/9/Appendices.pdf; http://pendeta.um.edu.my/client/default/search/results?qu=Computational+and+theoretical+studies+on+ZnS%5Bx%5DSe%5B1-x%5D+%280%E2%89%A4x%E2%89%A41%29&te=; http://studentsrepo.um.edu.my/3874/

The aim of this work is to study a theory of the energy band gap of ZnSxSe1-x (0≤ x ≤1) materials, and to obtain the density of states (DOS) in a quantizing magnetic field. From k .p perturbation theory, momentum matrix elements and energy eigenvalue of the Zn-S-Se alloy are derived. An empirical relationship where (μ*)-1=(mc)-1+(mv)-1, and mc, mv are the electron and hole rest masses respectively, is incorporated in the derivation of the energy gap equation The perturbation theory is also extended to include the spin-orbit interaction leading to a different expression for the energy gap Third, the density of states (DOS) for ZnSxSe1-x in a quantizing magnetic field has been determined by the E-k relation. The energy gap calculated from CASTEP is considered the unperturbed energy gap, Eg0. The actual energy Eg is related to Eg0 and results obtained are in reasonable agreement with published results obtained from literature. Energy gap with spin-orbit interaction is higher than the values calculated using energy gap equation without spin. The DOS is shown to depend on the electron energy and the magnetic field. Fermi level is modified by the magnetic field.