Strong near-infrared photoluminescence in erbium/ytterbium codoped porous silicon

Erbium ions and ytterbium ions (1021 cm3) were electrochemically codoped into porous silicon. When compared with the Er-doped porous silicon we found two salient features in its photoluminescence. One is that the 1.54 μm emission of Er3+ ions was 50 times stronger under 980 nm laser excitation at room temperature. This is due to the high efficiency of the Yb3+ → Er3+ energy transfer. The other is that the photoluminescence intensity increases rapidly with temperature, while that in Er-doped porous silicon decreases monotonically with temperature. Our results show that the codoped ErYb porous silicon has a promising potential for the application in optical communications.