Sammynaiken, R. and Naftel, S. J and Sham, T. K. and Cheah, K. W. and Averboukh, B. and Huber, Rupert and Shen, Y. R. and Qin, G. G. and Ma, Z. C. and Zong, W. H. (2002) Structure and electronic properties of SiO₂/Si multilayer superlattices: Si K edge and L₃,₂ edge x-ray absorption fine structure study. Journal of Applied Physics 92 (6), pp. 3000-3006.
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We report an x-ray absorption fine structure study at the Si K and L3,2 edges of a series of Si/SiO2 superlattices (SL). The SL system comprises four periods of elemental silicon with a spacing of 1, 1.4, 2.2, and 2.6 nm sandwiched by a 1.5 nm silicon oxide and capped by a 3 nm silicon oxide layer. These systems exhibit electroluminescence and photoluminescence. X-ray absorption near edge structure (XANES) at both the Si K and L3,2 edge confirms that the Si layers are amorphous. Polarization dependent measurement at the Si K edge reveals that a distinct Si/SiO2 interface exists with strong Si–O bonding oriented preferentially closer to the surface normal. High resolution XANES at the Si L3,2 edge shows a noticeable blueshift of the edge threshold as the lattice spacing decreases, in good accord with quantum confinement. The results and their implications for the origin (quantum confinement and interface/oxide defects) of luminescence in these superlattice systems are discussed.
|Institutions:||Physics > Institute of Experimental and Applied Physics > Chair Professor Huber > Group Rupert Huber|
|Subjects:||500 Science > 530 Physics|
|Created at the University of Regensburg:||Unknown|
|Deposited On:||01 Feb 2011 11:17|
|Last Modified:||21 Jul 2011 02:06|