title: Site-sensitive energy transfer modes in Ca3Al2O6: Ce(3+)/Tb(3+)/Mn(2+) phosphors.
abstract: Ce(3+)/Eu(2+), Tb(3+) and Mn(2+) co-doping in single-phase hosts is a common strategy to achieve white-light phosphors via energy transfer, which provides a high color rendering index (CRI) value and good color stability. However, not all hosts are suitable for white-light phosphors due to inefficient energy transfer. In this study, the site-sensitive energy transfer from different crystallographic sites of Ce(3+) to Tb(3+)/Mn(2+) in Ca3Al2O6 has been investigated in detail. The energy transfer from purplish-blue Ce(3+) to Tb(3+) is an electric dipole-dipole mode, and the calculated critical distance (Rc) suggests the existence of purplish-blue Ce(3+)-Tb(3+) clusters. No energy transfer is observed from purplish-blue Ce(3+) to Mn(2+). In co-doped phosphors based on greenish-blue Ce(3+), however, the radiative mode dominates the energy transfer from Ce(3+) to Tb(3+), and an electric dipole-quadrupole interaction is responsible for the energy transfer from Ce(3+) to Mn(2+). A detailed discussion on the site-sensitive energy transfer modes might provide a new aspect to discuss and understand the possibilities and mechanisms of energy transfer, according to certain crystallographic sites in a complex host with different cation sites, as well as provide a possible approach in searching for single-phase white-light-emitting phosphors.
authors.affiliation: Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China), Hunan Normal University, Changsha 410081, China.
authors.forename: Jilin
authors.initials: J
authors.lastname: Zhang
authors.forename: Yani
authors.initials: Y
authors.lastname: He
authors.forename: Zhongxian
authors.initials: Z
authors.lastname: Qiu
authors.forename: Weilu
authors.initials: W
authors.lastname: Zhang
authors.forename: Wenli
authors.initials: W
authors.lastname: Zhou
authors.forename: Liping
authors.initials: L
authors.lastname: Yu
authors.forename: Shixun
authors.initials: S
authors.lastname: Lian
mesh_terms: D017607:Aluminum Compounds / Q000737:chemistry*; D017610:Calcium Compounds / Q000737:chemistry*; D002586:Cesium / Q000737:chemistry*; D004735:Energy Transfer; D008027:Light; D008345:Manganese / Q000737:chemistry*; D011789:Quantum Theory; D013053:Spectrophotometry; D013696:Temperature; D013725:Terbium / Q000737:chemistry*
chemical_list: D017607:Aluminum Compounds; D017610:Calcium Compounds; D013725:Terbium; C035219:calcium aluminate; D002586:Cesium; D008345:Manganese