Université Bordeaux 1, CNRS/IN2P3, Centre d'Etudes Nucléaires de Bordeaux Gradignan, CENBG, Chemin du Solarium, BP120, 33175 Gradignan, France.
J Phys Condens Matter. 2012 Mar 28;24(12):125801. doi: 10.1088/0953-8984/24/12/125801. Epub 2012 Feb 28.
Single crystals of 4H-SiC were irradiated with swift heavy ions (332 MeV Ti, 106 MeV Pb and 2.7 GeV U) in the electronic energy loss regime. The resulting damage was investigated with UV-visible optical absorption spectroscopy and micro-Raman spectroscopy. The evolution of the Raman data with fluence shows an accumulation of isolated point defects without amorphization of the material and a partial recrystallization of the structure, but only at the lowest fluence. Furthermore, the longitudinal optical phonon-plasmon coupling mode disappears upon irradiation, suggesting a strong perturbation of the electronic structure. This evolution is consistent with the optical bandgap decrease and the Urbach edge broadening that was also previously observed for the irradiation with 4 MeV Au ions.
将 4H-SiC 单晶体在电子能量损失区用 swift 重离子（332 MeV Ti、106 MeV Pb 和 2.7 GeV U）辐照。用紫外-可见光学吸收光谱和微拉曼光谱研究了由此产生的损伤。随着辐照剂量的增加，拉曼数据的演化表明孤立的点缺陷不断积累，而材料没有非晶化，结构部分再结晶，但只在最低的辐照剂量下发生。此外，纵向光学声子-等离子体耦合模式在辐照后消失，表明电子结构受到强烈的干扰。这种演化与之前用 4 MeV Au 离子辐照时观察到的光学带隙减小和 Urbach 边展宽一致。
