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Site‐Selective Occupancy of Eu 2+ Toward Blue‐Light‐Excited Red Emission in a Rb 3 YSi 2 O 7 :Eu Phosphor
Author(s) -
Qiao Jianwei,
Ning Lixin,
Molokeev Maxim S.,
Chuang YuChun,
Zhang Qinyuan,
Poeppelmeier Kenneth R.,
Xia Zhiguo
Publication year - 2019
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201905787
Subject(s) - phosphor , excited state , color rendering index , luminescence , ion , crystal field theory , materials science , light emitting diode , optoelectronics , analytical chemistry (journal) , chemistry , atomic physics , physics , organic chemistry , chromatography
Establishing an effective design principle in solid‐state materials for a blue‐light‐excited Eu 2+ ‐doped red‐emitting oxide‐based phosphors remains one of the significant challenges for white light‐emitting diodes (WLEDs). Selective occupation of Eu 2+ in inorganic polyhedra with small coordination numbers results in broad‐band red emission as a result of enhanced crystal‐field splitting of 5d levels. Rb 3 YSi 2 O 7 :Eu exhibits a broad emission band at λ max =622 nm under 450 nm excitation, and structural analysis and DFT calculations support the concept that Eu 2+ ions preferably occupy RbO 6 and YO 6 polyhedra and show the characteristic red emission band of Eu 2+ . The excellent thermal quenching resistance, high color‐rendering index R a (93), and low CCT (4013 K) of the WLEDs clearly demonstrate that site engineering of rare‐earth phosphors is an effective strategy to target tailored optical performance.