title: Tunable Luminescence Contrast of Na0.5Bi4.5Ti4O15:Re (Re = Sm, Pr, Er) Photochromics by Controlling the Excitation Energy of Luminescent Centers.
abstract: High luminescent switching contrast of photochromic materials is extremely important in improving the sensitivity and resolution of optical switches and high-density optical data storage devices. To date, conventional methods, such as tuning absorption and emission bands based on electron or resonance energy transfer mechanisms in well-known organic photochromic molecules or compounds, have routinely been adopted to tune luminescent switching behavior. However, these strategies and mechanisms are not effectively applied to luminescence switching in inorganic materials because their crystal structures differ strongly from those of organic materials. In this paper, we report a new method to significantly tune the luminescent switching contrast by modifying the excitation energy of luminescent centers in a newly synthesized photochromism material: Na0.5Bi4.5Ti4O15:Re (Re = Sm, Pr, Er). A significant enhancement of luminescence switching contrast was achieved when the luminescent centers were excited by low energy photons at a given irradiation wavelength, intensity, and time, compared with high excitation energy photons. The trend "the lower the excitation energy, the higher the luminescence switching contrast" is universal in different rare earth ion-doped Na0.5Bi4.5Ti4O15ferroelectrics. The changes in the luminescent switching contrast based on excitation energy are ascribed to nonradiative energy transfer from the luminescent center to the color center by dipole-dipole interactions according to Dexter theory. This possible utilization of excitation energy at lower energy levels is usually less destructive to both information recording and the recording material itself during luminescent readout processes while achieving higher luminescence switching contrast.
authors.affiliation: School of Materials and Metallurgy, Inner Mongolia University of Science and Technology , 7# Arerding Street, Kun District, Baotou 014010, China.
authors.forename: Qiwei
authors.identifier: http://orcid.org/0000-0003-2565-7693
authors.initials: Q
authors.lastname: Zhang
authors.forename: Yao
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: School of Materials and Metallurgy, Inner Mongolia University of Science and Technology , 7# Arerding Street, Kun District, Baotou 014010, China.
authors.forename: Haiqin
authors.initials: H
authors.lastname: Sun
authors.forename: Wei
authors.initials: W
authors.lastname: Geng
authors.affiliation: Functional Materials Research Laboratory, School of Materials Science and Engineering, Tongji University , 4800 Caoyang Road, Shanghai 201804, China.
authors.forename: Xusheng
authors.initials: X
authors.lastname: Wang
authors.affiliation: School of Materials and Metallurgy, Inner Mongolia University of Science and Technology , 7# Arerding Street, Kun District, Baotou 014010, China.
authors.forename: Xihong
authors.initials: X
authors.lastname: Hao
authors.affiliation: School of Materials and Metallurgy, Inner Mongolia University of Science and Technology , 7# Arerding Street, Kun District, Baotou 014010, China.
authors.forename: Shengli
authors.initials: S
authors.lastname: An
keywords: luminescent readout; luminescent switching contrast; nonradiative energy transfer; optical data storage; photochromism