Albuquerque, Eudenilson Lins deSesion Júnior, Paulo Dantas2014-12-172009-06-082014-12-172005-11-12SESION JÚNIOR, Paulo Dantas. Confinamento de fónons ópticos em estruturas piezoelétricas periódicas e quasiperiódicas. 2005. 71 f. Dissertação (Mestrado em Física da Matéria Condensada; Astrofísica e Cosmologia; Física da Ionosfera) - Universidade Federal do Rio Grande do Norte, Natal, 2005.https://repositorio.ufrn.br/jspui/handle/123456789/16552We study the optical-phonon spectra in periodic and quasiperiodic (Fibonacci type) superlattices made up from III-V nitride materials (GaN and AlN) intercalated by a dielectric material (silica - SiO2). Due to the misalignments between the silica and the GaN, AlN layers that can lead to threading dislocation of densities as high as 1010 cm−1, and a significant lattice mismatch (_ 14%), the phonon dynamics is described by a coupled elastic and electromagnetic equations beyond the continuum dielectric model, stressing the importance of the piezoelectric polarization field in a strained condition. We use a transfer-matrix treatment to simplify the algebra, which would be otherwise quite complicated, allowing a neat analytical expressions for the phonon dispersion relation. Furthermore, a quantitative analysis of the localization and magnitude of the allowed band widths in the optical phonon s spectra, as well as their scale law are presented and discussedapplication/pdfAcesso AbertoFónonsFónons ópticosEstruturas periódicasEstruturas quasi-periódicasSemicondutoresNitretosPhononsOptical-phononPeriodical structuresQuasiperiodic structuresSaemiconductorsNitridemasterThesisCNPQ::CIENCIAS EXATAS E DA TERRA::FISICA