Mechanism of photoexcitation of oxide-related emission bands in Si–SiO₂ systems

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• 作者：Korsunska ; N. ; Baran ; M. ; Khomenkova ; L. ; Yukhymchuk ; V. ; Goldstein ; Y. ; Savir ; E. ; Jedrzejewski ; J.
• 关键词：Si&ndash ; SiO₂ systems ; Si nanocrystal ; Oxide defect ; Luminescence ; Excitation ; EPR
• 刊名：Materials Science and Engineering: C
• 出版年：2003
• 出版时间：December 15, 2003
• 年：2003
• 卷：23
• 期：6-8
• 页码：691-696
• 全文大小：283 K

文摘

The excitation process of oxide-related centers in magnetron sputtered Si–SiO₂ systems with Si nanocrystals of different sizes is investigated by photoluminescence, EPR and Raman scattering methods. It is found that the photoluminescence spectra of the systems studied contain four bands. The infrared band (1.38–1.54 eV) can be ascribed to exciton recombination in Si crystallites, while the other bands (at 1.7, 2.06 and 2.32 eV) can be attributed to oxide-related defects. Besides intra-defect transitions, the excitation of oxide defects due to light absorption in Si crystallites was found. It is shown that the effectiveness of this excitation channel decreases with the increase of Si crystallite sizes. The mechanism of excitation of oxide-related centers via an Auger process with bound carrier participation is discussed.