Room temperature and long-lasting blue phosphorescence of Cr-doped α-Al2O3 nanowires

Aligned α-alumina nanowires were synthesized employing chromium oxide and aluminum as raw materials at temperature of 1250 °C. The as-prepared products exhibited room temperature and long-lasting phosphorescence at 470 nm, in addition to the well-known 694 nm photoluminescence. A possible explanation was proposed.