Role of electronic excitations and nuclear collisions for color center creation in Al<sub>xsub>Ga<sub>1sub><sub>−sub><sub>xsub>N semiconductors
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- 作者：F. Moisy ; C. Grygiel ; A. Ribet ; M. Sall ; E. Balanzat ; I. Monnet
- 关键词：Nitride semiconductors ; Swift Heavy Ions ; Point defects ; Electronic excitations ; Nuclear collisions
- 刊名：Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
- 出版年：2016
- 出版时间：15 July 2016
- 年：2016
- 卷：379
- 期：Complete
- 页码：246-250
- 全文大小：671 K
文摘
In this work, Al<sub>xsub>Ga<sub>1sub><sub>−sub><sub>xsub>N (x = 0; 0.1; 0.3; 0.5; 0.65; 0.7; 0.8; 1) wurtzite epilayers, grown on c-plane sapphire substrates, have been irradiated with Swift Heavy Ions at GANIL facility. Modifications induced by irradiation are characterized with in-situ optical absorption spectroscopy at 15 K. Spectra of these irradiated alloys exhibit optical absorption band formation, related to new energy levels in their bandgaps, whose positions only depend on the composition of the layer. However, these absorption bands are not observed in the Al<sub>xsub>Ga<sub>1sub><sub>−sub><sub>xsub>N with Al molar fraction less than 0.3, likely because the energy level of the corresponding defect is located above the conduction band. Moreover, using different irradiation conditions, a coupled effect between nuclear collisions and electronic excitations for these color center creation have been investigated. A synergy between these two phenomena has been shown and appears to be independent of the composition of the alloy.