Synthesis, photoluminescence, and photostability of Y2O3:Bi3+,Eu3+ nanosheets

Abstract Y 2 O 3 :Bi 3+ ,Eu 3+ nanosheets are produced by calcinating hydrothermally synthesized precursor nanosheets. Transmission electron microscope observation confirms that the sheet-like morphology remains unchanged after calcination at either 600 or 800 °C for 2 h. The excitation spectrum monitored at 612 nm emission corresponding to the 5 D 0 → 7 F 2 transition of Eu 3+ has a broad band at 331 nm that is attributed to the 6s 2 →6s6p transition of Bi 3+ . The Y 2 O 3 :Bi 3+ ,Eu 3+ nanosheets therefore exhibit the red emission of Eu 3+ through energy transfer from Bi 3+ to Eu 3+ following excitation of Bi 3+ . The photostability of Y 2 O 3 :Bi 3+ ,Eu 3+ nanosheets is evaluated from their change in photoluminescence intensity during continuous excitation. The photoluminescence intensity of Y 2 O 3 :Bi 3+ ,Eu 3+ nanosheets decreases to more than 90% of the initial intensity soon after irradiation begins, and then the photoluminescence intensity gradually recovers. In contrast, the photoluminescence intensity of YVO 4 :Bi 3+ ,Eu 3+ nanoparticles decreases to 53.6% of the initial intensity during excitation. These results indicate that Y 2 O 3 :Bi 3+ ,Eu 3+ nanosheets have higher photostability than YVO 4 :Bi 3+ ,Eu 3+ nanoparticles.