A quantum-splitting phosphor exploiting the energy transfer from anion excitons to Tb3+ in CaSO4 : Tb,Na

作者：Lakshmanan Arunachalam R^*; Kim Seon Bae; Jang Hyun M; Kum Byung G; Kang Bong K; Heo Soonyeong; Seo Dongsung

来源：Advanced Functional Materials, 2007, 17(2): 212-218.

DOI：10.1002/adfm.200600010

Wide-bandgap materials doped with rare-earth ions are currently of great interest as new vacuum ultraviolet (VUV) phosphors for lighting and displays. Ibis paper reports the development of a highly sensitive green phosphor, CaSO4:Tb,Na, which exhibits a quantum efficiency higher than 100% by exploiting the energy-transfer mechanism from anion excitons to the activator ions, Tb3+. The VUV excitation spectra of CaSO4:Tb3+ with Na+ as a charge compensator show two prominent excitation bands at 147 and 216 nm. The former band is attributed to the charge-transfer excitations within SO42- complexes while the latter was assigned to the 48 -> 4f(7)5d transitions on Tb3+. The energy-transfer mechanism from anion excitons to Tb3+ strongly raises the possibility of two-photon emission via a second-order down-conversion under the VUV excitation, which is basically a new approach in the goal of achieving a quantum-splitting phosphor.

• 出版日期2007-1-22