Disorder effects produced by the Mn and H incorporations on the optical absorption edge of Ga1-xMnxAs:H nanocrystalline films

Autor(es)

Pereira, Andre L. J. ^[1] ; da Silva, J. H. Dias ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Paulista UNESP, Fac Ciencias, Adv Mat Grp, Dept Fis, BR-17033360 Bauru, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Non-Crystalline Solids; v. 354, n. 52-54, p. 5372-5377, DEC 15 2008.
• Citações Web of Science: 7

Resumo

The optical absorption edges of nanocrystalline Ga(1-x)Mn(x)As:H films (0.000 <= x <= 0.081) prepared by sputtering were analyzed. The influence of Mn and hydrogen incorporations were both investigated. The energy dispersive X-ray spectroscopy and X-ray diffraction measurements show that the films are nanocrystalline and do not display any evidence of Mn segregation, or of any other secondary phase formation. The transmittance measurements in the ultraviolet-visible-near infrared range allow us to calculate the absorption coefficient, the optical gap, and the Urbach energy. The hydrogenated Ga(1-x)Mn(x)As films presented wider gaps and smaller Urbach energies than its non-hydrogenated counterparts. In the hydrogenated films a linear correlation was observed between the decrease of the optical gap and the increase of the Urbach energy, which we have attributed to potential fluctuations and disorder induced by the Mn incorporation. (C) 2008 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 05/03463-5 - Efeitos da incorporação de Mn em filmes nanocristalinos Ga IND. 1-x Mn IND. xAs preparados por sputtering
• Beneficiário: André Luis de Jesus Pereira
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 05/02249-0 - Controle dos parâmetros de deposição de filmes hetero-epitaxiais de GaN e Ga(1-x)Mn(x)N preparados por RF magnetron sputtering
• Beneficiário: Jose Humberto Dias da Silva
• Modalidade de apoio: Auxílio à Pesquisa - Regular