title: Efficient energy transfer from inserted CdTe quantum dots to YVO₄:Eu³⁺ inverse opals: a novel strategy to improve and expand visible excitation of rare earth ions.
abstract: Rare earth (RE)-based phosphors demonstrate sharp emission lines, long lifetimes and high luminescence quantum yields; thus, they have been employed in various photoelectric devices, such as light-emitting diodes (LEDs) and solar spectral converters. However, their applications are largely confined by their narrow excitation bands and small absorption cross sections of 4f-4f transitions. In this paper, we demonstrate a novel strategy to improve and expand the visible excitation bands of Eu(3+) ions through the interface energy transfer (ET) from CdTe quantum dots (QDs) to YVO₄:Eu(3+) inverse opal photonic crystals (IOPCs). The significant effects observed in the CdTe QDs/YVO₄:Eu(3+) IOPCs composites were that the excitation of Eu(3+) ions was continuously extended from 450 to 590 nm and that the emission intensity of the (5)D₀-(7)FJ transitions was enhanced ∼20-fold, corresponding to the intrinsic (7)F₁-(5)D₁ excitation at 538 nm. Furthermore, in the IOPC network, the ET efficiency from the QDs to YVO₄:Eu(3+) was greatly improved because of the suppression of energy migration among the CdTe QDs, which gave an optimum ET efficiency as high as 47%. Besides, the modulation of photonic stop bands (PSBs) on the radiative transition rates of the QDs and Eu(3+) ions was studied, which showed that the decay lifetime constants for Eu(3+) ions were independent of PSBs, while those of QDs demonstrated a suppression in the PSBs. Their physical nature was explained theoretically.
authors.affiliation: State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, China. songhw@jlu.edu.cn.
authors.forename: Yongsheng
authors.initials: Y
authors.lastname: Zhu
authors.forename: Shaobo
authors.initials: S
authors.lastname: Cui
authors.forename: Xu
authors.initials: X
authors.lastname: Chen
authors.forename: Wen
authors.initials: W
authors.lastname: Xu
authors.forename: Pingwei
authors.initials: P
authors.lastname: Zhou
authors.forename: Yunfeng
authors.initials: Y
authors.lastname: Wang
authors.forename: Lin
authors.initials: L
authors.lastname: Xu
authors.forename: Hongwei
authors.initials: H
authors.lastname: Song
authors.forename: Ling
authors.initials: L
authors.lastname: Huang
authors.forename: Wei
authors.initials: W
authors.lastname: Huang