Europhys. Lett.
Volume 60, Number 2, October 2002
Page(s) 323 - 328
Section Interdisciplinary physics and relates areas of science and technology
Published online 01 October 2002
DOI: 10.1209/epl/i2002-00353-8

Europhys. Lett., 60 (2) , pp. 323-328 (2002)

Suppression of UV photoluminescence in sandwich-structured $\chem{Si/C}$ composite films

Y. Zhu, C. L. Yuan, R. Liu and P. P. Ong

Department of Physics, Block 12, Faculty of Science, National University of Singapore 2 Science Drive 3, Singapore 117542

(Received 22 May 2002; accepted 2 August 2002)

Thin films of composite silicon/carbon ( $\chem{Si/C}$) were prepared by pulsed-laser ablation alternately on $\chem{C}$ and $\chem{Si}$ materials on a rotary target, followed by vacuum deposition of the ablated materials on an ultra-clean glass substrate. The film structure consisted of alternate nanolayers of $\chem{Si}$ nanocrystals and amorphous $\chem{C}$, with a fairly sharp demarcation boundary between adjacent layers forming well-defined sandwich structures. At room temperature, this composite nanolayered structure was found to yield much lower photoluminescent (PL) emission in the ultra violet region (300-390 $\un{nm}$) in comparison with that obtained for pure $\chem{Si}$ or for $\chem{Si/Al_2O_3}$ thin films (see ZHU Y., WANG H. AND ONG P. P. J. Phys. D, 33 (2000) 1965, and ZHU Y. AND ONG P. P. J. Phys. Condens. Matter , 13 (2001) L1). The suppression mechanism of the UV PL emission appeared to occur in the interfacial surfaces between adjacent crystalline $\chem{Si}$ and amorphous $\chem{C}$ layers. It provides a possible way to selectively filter out the usually undesirable UV component of the PL emission from the silicon nanoparticles.

81.07.-b - Nanoscale materials and structures: fabrication and characterization.
78.55.Ap - Elemental semiconductors.

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