title: Efficient near-infrared downconversion and energy transfer mechanism of ce(3+)/yb(3+) codoped calcium scandate phosphor.
abstract: An efficient near-infrared (NIR) downconversion has been demonstrated in CaSc2O4: Ce(3+)/Yb(3+) phosphor. Doping concentration optimized CaSc2O4: 1%Ce(3+)/5%Yb(3+) shows stronger NIR emission than doping concentration also optimized typical YAG: 1%Ce(3+)/5%Yb(3+) under 470 nm excitation. The NIR emission from 900 to 1100 nm is enhanced by a factor of 2.4. In addition, the main emission peak of Yb(3+) in the CaSc2O4 around 976 nm matches better with the optimal spectral response of the c-Si solar cell. The visible and NIR spectra and the decay curves of Ce(3+): 5d → 4f emission were used to demonstrate the energy transfer from Ce(3+) ions to Yb(3+) ions. The downconversion phenomenon has been observed under the direct excitation of Ce(3+) ions. On analyzing the dependence of energy transfer rate on Yb(3+) ion concentration, we reveal that the energy transfer (ET) from Ce(3+) ions to Yb(3+) ions in CaSc2O4 occurs mainly by the single-step ET process. Considering that the luminescence efficiency of CaSc2O4: Ce(3+) is comparable to that of commercial phosphor YAG: Ce(3+), the estimated maximum energy transfer efficiency reaches 58% in the CaSc2O4: 1%Ce(3+)/15%Yb(3+) sample, indicating that CaSc2O4: Ce(3+)/Yb(3+) sample has the potential in improving the conversion efficiency of c-Si solar cells.
authors.affiliation: †School of Basic Sciences, ChangChun University of Technology, A1018 Huguang Road, Changchun 130012, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.affiliation: †School of Basic Sciences, ChangChun University of Technology, A1018 Huguang Road, Changchun 130012, China.
authors.forename: Li
authors.initials: L
authors.lastname: Chen
authors.affiliation: ‡State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 3888 Eastern South Lake Road, Changchun 130033, China.
authors.forename: Zhendong
authors.initials: Z
authors.lastname: Hao
authors.affiliation: ‡State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 3888 Eastern South Lake Road, Changchun 130033, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Zhang
authors.affiliation: ‡State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 3888 Eastern South Lake Road, Changchun 130033, China.
authors.forename: Ligong
authors.initials: L
authors.lastname: Zhang
authors.affiliation: ‡State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 3888 Eastern South Lake Road, Changchun 130033, China.
authors.forename: Yongshi
authors.initials: Y
authors.lastname: Luo
authors.affiliation: ‡State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 3888 Eastern South Lake Road, Changchun 130033, China.
authors.forename: Jiahua
authors.initials: J
authors.lastname: Zhang