Energy transfer and 2 μm emission in Tm3+/Ho3+ co-doped (Y0.87La0.1Zr0.03)2O3 nanopowders

(Y 0.87 La 0.1 Zr 0.03 ) 2 O 3 nanopowders doped with various concentrations of Tm 3+ and Ho 3+ were prepared by the citrate method. The standard cubic Y 2 O 3 phase can be matched in the Tm 3+ /Ho 3+ co-doped (Y 0.87 La 0.1 Zr 0.03 ) 2 O 3 nanopowders. The nanopowders exhibit average particle sizes of 40, 60, 80 and 100 nm after calcinated at 900, 1000, 1100 and 1200 °C, respectively. The energy transfer from Tm 3+ to Ho 3+ and the optimum fluorescence emission around 2 μm were investigated. Results indicate that the emission bands at around 1.86 and 1.95 μm correspond to 3 F 4 → 3 H 6 transition of Tm 3+ and 5 I 7 → 5 I 8 transition of Ho 3+ , respectively. Better spectral properties were achieved in Tm 3+ /Ho 3+ co-doped (Y 0.87 La 0.1 Zr 0.03 ) 2 O 3 nanopowders with the average size of 100 nm obtained at the conditions of the treatment of precursors calcinated at 1200 °C for 2 h doped with 1.5 mol% Tm 3+ and 1 mol% Ho 3+ .