title: Origin and Luminescence of Anomalous Red-Emitting Center in Rhombohedral Ba9Lu2Si6O24:Eu(2+) Blue Phosphor.
abstract: We obtain a blue phosphor, Ba9Lu2Si6O24:Eu(2+) (BLS:Eu(2+)), which shows a strong emission peak at 460 nm and a weak tail from 460 to 750 nm. A 610 nm red emission is observed for the first time in this kind of rhombohedral structure material, which is much different from the same crystal structure of Ba9Sc2Si6O24:Eu(2+) and Ba9Y2Si6O24:Eu(2+). The luminescence properties and decays from 10 to 550 K are discussed. The new red emission arises from a trapped exciton state of Eu(2+) at the Ba site with a larger coordination number (12-fold). It exhibits abnormal luminescence properties with a broad bandwidth and a large Stokes shift. Under the 400 nm excitation, the external quantum efficiency of BLS:Eu(2+) is 45.4%, which is higher than the 35.7% for the commercial blue phosphor BAM:Eu(2+). If the thermal stability of BLS:Eu(2+) can be improved, it will show promising applications in efficient near-UV-based white LEDs.
authors: Ningbo Institute of Materials Technology and Engineering (NIMTE), Chinese Academy of Sciences (CAS) , Ningbo, 315201, China.
authors: Yongfu
authors: Y
authors: Liu
authors: Ningbo Institute of Materials Technology and Engineering (NIMTE), Chinese Academy of Sciences (CAS) , Ningbo, 315201, China.|Department of Chemistry, College of Science, Shanghai University , Shanghai, 200444, China.
authors: Changhua
authors: C
authors: Zhang
authors: Department of Chemistry, College of Science, Shanghai University , Shanghai, 200444, China.
authors: Zhixuan
authors: Z
authors: Cheng
authors: College of Science, Hunan Agricultural University , No. 1 Nongda Road, Changsha, 410128, China.
authors: Zhi
authors: Z
authors: Zhou
authors: Ningbo Institute of Materials Technology and Engineering (NIMTE), Chinese Academy of Sciences (CAS) , Ningbo, 315201, China.
authors: Jun
authors: J
authors: Jiang
authors: Ningbo Institute of Materials Technology and Engineering (NIMTE), Chinese Academy of Sciences (CAS) , Ningbo, 315201, China.
authors: Haochuan
authors: H
authors: Jiang