Photoluminescence of ytterbium-doped porous silicon

Abstract

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 μm which is assigned to the intrashell 4f‐4f transitions ²F_5/2 → ²F_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 generated in the host porous silicon layers.