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 1.54μm emission of Er3+ ions was 50 times stronger under 980nm 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 Er∕Yb porous silicon has a promising potential for the application in optical communications.