STRUCTURAL, ELECTRONICS AND PHONON DISPERSION RELATIONS OF BI-III BINARY COMPOUND SEMICONDUCTORS USING DENSITY FUNCTIONAL THEORY
1Amusa, R.A. and 2 Oyewande, E.O.
1Department of Science Laboratory Technology, Federal Polytechnic Ilaro-Ogun State.
2Department of Physics, University of Ibadan, Ibadan, Oyo State.
Email: alade_amusa2000@yahoo.com
ABSTRACT: Phonon dispersion relations of semiconductors especially III-Bi binary compounds are of immense importance in the study of structural and vibrational properties of semiconductor materials. In this paper structural and phonon frequencies at high symmetry points using local density and generalized gradient approximations within density functional perturbation theory were calculated and compared with a view to know the influence of pseudopotentials on the investigated properties and variation of acoustic and optics frequencies of the compounds with atomic orbitals of the selected compounds . Our results reveal that only BBi show higher values of both longitudinal and transverse optical frequencies which can be attributed to the fact that BBi binary compound is the only optoelectronic material that has direct energy, in addition acoustic and optical frequencies decrease for local density approximation than the generalized gradient approximation in BBi compound while they are greater for LDA than the GGA frequencies in AlBi compound. The phonon frequencies calculated will be useful in phonon engineering where vibrational properties of materials are employed.