title: Enhanced rare earth photoluminescence in inverse opal photonic crystals and its application for pH sensing.
abstract: Concentration quenching effects of identical rare earth (RE) activator ions and energy transfer (ET) between different RE ions often compromise the photoluminescence (PL) quantum efficiency in RE based luminescence materials. Here, we demonstrate that in NaGd(WO4)2:Tb(3+), Eu(3+) inverse opal photonic crystals (IOPCs), the suppression of the emission line located in the photonic stop band (PSB) and a dramatic increase of the lifetimes of Eu(3+) and Tb(3+) ions are observed. More interestingly, the concentration quenching among Eu(3+) ions and ET from Tb(3+) to Eu(3+) is significantly relieved owing to the periodic empty cavity structure of IOPCs. As a consequence, the luminescent quantum efficiency (QE) of the NaGd(WO4)2:Tb(3+), Eu(3+) IOPCs increases ∼2 times more than that of crushed NaGd(WO4)2:Tb(3+), Eu(3+) powder. In addition, a reusable pH sensor with good linear response (pH 5-10) has been designed based on the high surface-to-volume ratio, high connectivity, and enhanced luminescence of NaGd(WO4)2:Tb(3+), Eu(3+)IOPCs, which could be applied to the dynamical detection of pH value.
authors: College of Physics and Electronic Engineering, Nanyang Normal University, Nanyang 473061, People's Republic of China. State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, People's Republic of China.
authors: Yongsheng
authors: Y
authors: Zhu
authors: Shaobo
authors: S
authors: Cui
authors: Yinhua
authors: Y
authors: Wang
authors: Mao
authors: M
authors: Liu
authors: Cheng
authors: C
authors: Lu
authors: Abhinay
authors: A
authors: Mishra
authors: Wen
authors: W
authors: Xu