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Master's Dissertation
DOI
10.11606/D.54.1992.tde-08122010-100311
Document
Author
Full name
Salviano de Araújo Leão
E-mail
Institute/School/College
Knowledge Area
Date of Defense
Published
São Carlos, 1992
Supervisor
Committee
Hipolito, Oscar (President)
Degani, Marcos Henrique
Oliveira, Luiz Eduardo Moreira Carvalho de
Title in Portuguese
Espalhamento elétron-fônon ótico em fios quânticos de GaAs/Ga1-XAlXAs
Keywords in Portuguese
Fios quânticos
Interação elétron-fônon
Abstract in Portuguese
Investigamos os efeitos de tamanho e do potencial de confinamento finito V0 nas taxas de espalhamento de absorção e de emissão de elétrons interagindo com os fônons longitudinais ópticos (fônons LO) de um fio quântico cilíndrico de GaAs à temperatura ambiente. Calculamos as taxas de espalhamento inter e intra-sub-banda e a taxa de espalhamento total para uma temperatura de 300 K, pois nesta temperatura o mecanismo de espalhamento dominante em semicondutores do tipo III-V é aquele devido aos fônons LO. Qualitativamente a taxa de emissão intra-sub-banda neste sistema tem o mesmo comportamento da sua correspondente em estruturas 2D. Para a absorção encontramos uma mudança suave de comportamento da taxa de absorção intra-sub-banda quando o raio do fio é da ordem do diâmetro do polaron (ou seja, da ordem de 80 ANGSTROM). Para raios pequenos ela tem um comportamento similar ao do bulk, mas para raios maiores ela cresce até atingir um máximo e depois cai monotonicamente à medida que aumentamos a energia do portador. Vimos que, o tamanho do fio e o potencial de confinamento têm grande influência na taxa de espalhamento total.
Title in English
Electron-optical phonon scattering in quantum wires of GaAs/Ga1-XAlXAs
Keywords in English
Electron-phonon interaction
Quantum wires
Abstract in English
We investigated the size effects and the effects of the finite confining potential V0 on the absorption and emission scattering rates of electron interacting with longitudinal optical (LO) phonons for a cylindrical GaAs quantum wire. We calculated the inter and intrasubband total scattering rate for a temperature of 300K, because in this temperature the dominant mechanism of scattering in semiconductors III-V is that due LO phonons. Qualitatively the intrasubband emission scattering rate in this system has the same behavior of the correspondent in 2D structures. For absorption we found a smooth change in the intrasubband absorption scattering rate behavior when the radius the wire is near the polaron diameter (ie, about 80 ANGSTROM). For small radius the scattering rate has a similar behavior as that of the bulk, but for large radius it increases until reach a maximum and after ir drops monotonicaly with increase of carrier energy. We found that the size effect and the confining potential have a large influence in the total scattering rate
 
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Publishing Date
2011-10-20
 
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