Yb3+‐related photoluminescence is observed at room temperature from Yb‐doped porous silicon layers prepared by the electro‐chemical method developed by our group for Er doping of porous silicon layers. After rapid thermal annealing in a pure argon atmosphere at high temperatures (above ∼ 900 °C), samples show a sharp photoluminescence band at around 1.0 &mgr;m which is assigned to the intrashell 4f‐4ftransitions2F5/2→2F7/2of 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 generated in the host porous silicon layers. ©1995 American Institute of Physics.