PHOTOLUMINESCENCE OF YTTERBIUM-DOPED POROUS SILICON

Yb3+-related photoluminescence is observed at room temperature from Yb -doped porous silicon layers prepared by the electro-chemical method d eveloped by our group for Er doping of porous silicon layers. After ra pid thermal annealing in a pure argon atmosphere at high temperatures (above similar to 900 degrees C), samples show a sharp photoluminescen ce band at around 1.0 mu m which is assigned to the intrashell 4f-4f t ransitions F-2(5/2) --> F-2(7/2) of Yb3+. The enlarged energy bandgap of silicon as a result of anodization makes possible the excitation of Yb3+ 4f-electrons with the recombination energy of photocarriers gene rated in the host porous silicon layers. (C) 1995 American Institute o f Physics.