Preparation, luminescence and potential application of rare earth Sm3+ -doped fluorphlogopite phosphors

Abstract

The development of new inorganic phosphors for the use of latent fingerprint detection has aroused attention. In this work, a series of rare earth Sm3+ -doped fluorphlogopite phosphors were prepared through the conventional solid state reaction method, which involve the Sm3+ -doped sodium fluorphlogopite and sodium tetrasilica fluorphlogopite by changing the interlayer cations and increasing the Si content. All the as-prepared fluorphlogopite samples were characterized with the X-ray diffraction, scanning electron microscopy, transmission electron microscopy, photoluminescence excitation and emission spectra and fluorescent decay measurement. The X-ray diffraction results indicate that the series of Sm3+ -doped synthetic-micas exhibit lamellar structure, and the introduction of Sm3+ has little influence on the structure of the samples. The photoluminescence measurements suggest that the phosphors can be efficiently excited with 402 nm, and emit the red light at about 600–604 and 647–651 nm corresponding to the 4G5/2 → 6H7/2 and 4G5/2 → 6H9/2 characteristic transitions of Sm3+, respectively. It is worth emphasizing that the luminescence intensity of Sm3+ in sodium tetrasilica fluorphlogopite host is tremendously enhanced and reaches more than 30-fold in comparison with the original fluorphlogopite, which should be due to the obvious increase of the activator Sm3+ quenching concentration. The Sm3+ -doped sodium tetrasilica fluorphlogopite phosphor was applied to detect latent fingerprints on different substrates, showing clear images under the irradiation of near-ultraviolet and violet light. The structurally-modified fluorphlogopite: Sm3+ mica may be a red-light emitting candidate for the latent fingerprint detection as well as other photofunctional fields.