Strongly luminescent Cr-doped alumina nanofibres

A large number of alumina nanofibres with strong photoluminescence was obtained in treated porous anodic alumina (PAA) film. The treatment includes three steps: doping the Cr into the high-purity aluminium by melting, anodizing the Cr-doped Al sheet to produce PAA followed by an etching process, and calcination. This routine yields a large number of alumina nanofibres with diameter about 80-150 nm, which were characterized by a scanning electron microscope and a transparent electron microscope. The obtained alumina nanofibres reveal very strong and sharp peaks in the photoluminescence spectrum, indicating their potential applications in nano-optics.