title: Concentration-Dominated Temperature-Dependence of Upconversion Luminescence in Gd6WO12 Nanophosphor Co-Doped with Er3+ and Yb3+.
abstract: Nanosized Gd6WO12 phosphors containing various Er3+ concentrations and fixed Yb3+ concentration were synthesized by a co-precipitation method. The crystal structure and microscopic morphology of the obtained nanophosphors were characterized by means of X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). Two-photon processes for both the green and red upconversion (UC) emissions were confirmed by analyzing the dependence of UC intensities on 980 nm laser working current. UC emission intensity changing with temperature displays different trends for the samples with different Er3+ concentrations. The experimental results indicated that thermal quenching behavior of UC luminescence could not be simply explained by crossover mechanism. The enhancement for green UC emission in the sample with higher Er3+ concentration was discussed. Finally, the ErS+ concentration dependence of UC luminescence was experimentally observed, and its mechanisms were analyzed.
authors.forename: Yanqiu
authors.initials: Y
authors.lastname: Zhang
authors.forename: Baojiu
authors.initials: B
authors.lastname: Chen
authors.forename: Xiangping
authors.initials: X
authors.lastname: Li
authors.forename: Jiashi
authors.initials: J
authors.lastname: Sun
authors.forename: Jinsu
authors.initials: J
authors.lastname: Zhang
authors.forename: Hui
authors.initials: H
authors.lastname: Zheng
authors.forename: Zhongli
authors.initials: Z
authors.lastname: Wu
authors.forename: Hua
authors.initials: H
authors.lastname: Zhong
authors.forename: Ruinian
authors.initials: R
authors.lastname: Hua
authors.forename: Haiping
authors.initials: H
authors.lastname: Xia