title: Up-conversion emissions characteristics of non-aqueous sol-gel derived RE3Al5O12 nanocrystals.
abstract: The RE3Al5O12 (REAG:Er3Al5O12, Er:Y3Al5O12 and Er:Yb3Al5O12) up-conversion (UC) nanocrystals have been prepared by the non-aqueous sol-gel method. The green and red UC emissions are attributed to the 2H(11/2), 4S(3/2) --> 4I(15/2) and 4F(9/2) --> 4I(15/2) transitions of Er3+, respectively, were obtained for all samples with a 975 nm semiconductor LD excitation. For Er3Al5O12 nanocrystals, the green and red UC emissions have similar intensities. Y and Yb ions have no evident effect on the peak positions, but strongly affected the intensities of the green and red UC emissions of the Er. A much higher intensity of the green relative to red UC emission was observed for Er:Y3Al5O12 nanocrystals, however, the red UC emission became predominant for Er:Yb3Al5O12 nanocrystals. It was suggested that the two-photon process was responsible for the green and red UC emissions mechanism for all the samples.
authors.affiliation: School of Science, Dalian Nationalities University, Dalian, 116600, P. R. China.
authors.forename: Bin
authors.initials: B
authors.lastname: Dong
authors.forename: Baosheng
authors.initials: B
authors.lastname: Cao
authors.forename: Chongxu
authors.initials: C
authors.lastname: Du
authors.forename: Zhiqing
authors.initials: Z
authors.lastname: Feng