Repositori URV

Identifier: imarina:5608738

Handle: https://hdl.handle.net/20.500.11797/imarina5608738

Authors:
William Barrera, ElixirCinta Pujol, MariaDiaz, FrancescChoi, Soo BongRotermund, FabianPark, Kyung HoJeong, Mun SeokCascales, Concepcion

Abstract:
Yb3+and Ln3+(Ln3+= Er3+or Tm3+) codoped Lu2O3nanorods with cubic Ia 3̄ symmetry have been prepared by low temperature hydrothermal procedures, and their luminescence properties and waveguide behavior analyzed by means of scanning near-field optical microscopy (SNOM). Room temperature upconversion (UC) under excitation at 980 nm and cathodoluminescence (CL) spectra were studied as a function of the Yb+concentration in the prepared nanorods. UC spectra revealed the strong development of Er3+4F9/2→4I15/2(red) and Tm3+1G4→3H6(blue) bands, which became the pre-eminent and even unique emissions for corresponding nanorods with the higher Yb3+concentration. Favored by the presence of large phonons in current nanorods, UC mechanisms that privilege the population of4F9/2and1G4emitting levels through phonon-assisted energy transfer and non-radiative relaxations account for these observed UC luminescence features. CL spectra show much more moderate development of the intensity ratio between the Er3+4F9/2→4I15/2(red) and2H11/2,4S3/2→4I15/2(green) emissions with the increase in the Yb3+content, while for Yb3+, Tm3+-codoped Lu2O3nanorods the dominant CL emission is Tm3+1D2→3F4(deep-blue). Uniform light emission along Yb3+, Er3+-codoped Lu2O3rods has been observed by using SNOM photoluminescence images; however, the rods seem to be too thin for propagation of light. © 2011 IOP Publishing Ltd.