硅中稀土掺杂层的光致发光研究及其关键问题

Investigation of the Layers Doped with Rare Earth Elements in Si Substrate and It's Key Problems

利用离子注入技术 ,对稀土掺杂到半导体单晶硅中的光致发光行为进行了研究。室温下得到了La ,Ce和Nd稀土掺杂层的蓝紫色光致发光光谱 ,并首次观测到硅中稀土掺杂层室温下的光致上转换发光现象。光致发光强度随着稀土掺杂量的增加和热处理温度的上升急剧增强。在紫外光激发下 ,发光强度随着激发光波长的减小而增大 ;在光致上转换过程中 ,发光强度随着激发波长的增加而上升。这表明光致发光强度与稀土元素的掺杂量、掺杂层的结构与热处理温度有密切的关系。文章对在室温下这些稀土掺杂层的光致发光行为进行了分析 ,并提出了硅中稀土掺杂层光致发光行为研究今后需要重点解决的几个主要问题。

The photoluminescence properties of rare earth doped silicon were investigated with ion beam technique. The photoluminescence spectra in the layers doped with ions of La, Ce and Nd were obtained at room temperature. At the same time, the up-conversion luminescence in the doped layers was observed. The intensities of both the luminescence and the up-conversion luminescence increased with increasing the doping dose and the treatment temperature. However, the intensities of the luminescence decreased with increasing the exciting wavelength between 220 nm and 300 nm; the intensities of the up-conversion luminescence increased with increasing the exciting wavelength between 600 nm and 800 nm. It was indicated that the luminescence and the up-conversion luminescence in the layers doped with ions of La, Ce and Nd depended on the doping dose, the heat treatment temperature and the exciting wavelength.