Simulação computacional do crescimento epitaxial de CdTe sobre Si(111)

• Autor(a) principal: Faria, Tatiana Estorani de
• Data de Publicação: 2008
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/4228
• topic: Filmes finos; Leis de escala; CdTe; Simulação computacional; Thin films; Scale laws; CdTe; Computer simulation; CNPQ::CIENCIAS EXATAS E DA TERRA::FISICA::FISICA DA MATERIA CONDENSADA

Several applications of CdTe have been proposed in the development of low cost and high-effcient electronic devices such as solar cells, gamma and X-ray nuclear detectors. Particularly, the HotWall Epitaxy (HWE) method for thin films growth has been used in several experiments at Universidade Federal de Viçosa [1, 2]. Recently, a model was proposed by Ferreira and Ferreira [3] to study this kind of growth, including diffusion and desorption governed by local microscopic configurations. This model describes the formation of CdTe quantum dots on Si substrates using HWE, which obeys the Volmer-Weber growth mode. In this work, we analyze the scaling behavior of such model for long deposition time, not previously considered; we propose a change in the model in order to achieve the diffusion between terraces symmetry. Finally, we extended the model to 2+1 dimensions, using a triangular lattice that represents the Si(111) substrate. The presented results show that this proposed model, with some changes, can qualitatively describe the experiments of CdTe epitaxial growth on Si(111). In one dimension we observed a dependence of the growth exponent with temperature, in agreement with Ferreira, Ribeiro, et al. [4]. In two dimensions, island formation was observed, even for just one monolayer of deposited material, following the Volmer-Weber growth mode experimentally observed. Examining the number of islands as a function of the temperature, we found two different growth regimes, one of them compatible with the experimental results of Ferreira, Paiva, et al. [1].