Tunable white light in trivalent europium single doped tin fluorophosphates ultra-low melting glass

Abstract

In recent years, low melting temperature glasses have received wide attention as the hosts of phosphor-converted light emitting diodes (pc-WLED). In this work, a series of trivalent europium doped tin fluorophosphates glasses were prepared by conventional melting method. Under ultraviolet excitation, the blue-green broadband emission from Sn 2+ activation centers in the glass matrix and the red emission of Eu 3+ ions together constituted a cool white luminescence. The spectra analysis was used to demonstrate the energy transfer between Sn 2+ centers and Eu 3+ ions. The results showed that Sn 2+ and Eu 3+ possessed independent intrinsic emission and mutual energy transfer simultaneously. The 5 D 4 and 5 G 2 excited states of Eu 3+ ion favored the energy transfer to Sn 2+ center, the 5 L 6 excited state of Eu 3+ ion would absorb more of the energy by the Sn 2+ ground state excitation to contribute on red emission. Therefore, the fluorescent glass can transform cool white light to warm white light by changing the excitation wavelength. The tunable white light is obtained in the WLED devices built with the glass and commercial UV chips.

Luminescent properties of Tb3+ doped sodium silica germanate glasses

“…A diversity of crystalline, non-crystalline, organic, and inorganic materials hosts has been studied, doped with optically active centers, for white or color light-emitting diodes (LEDs). These devices have attracted important interest due to their low energy consumption, brightness, longer life, and environmentally friendly characteristics [1][2][3][4][5].…”

ZnCl2-Enhanced Intrinsic Luminescence of Tin Chlorophosphate Glasses

“…Wang et al [8] reported that Sn-P-O-F (TFP) glasses without rare-earth elements can exhibit an intrinsic broadband visible emission under excitation of a 325 nm wavelength, but these glasses could not be used as the light source for LED excitation because the wavelength was too short. Subsequently, active ions such as Mn 2+ or Eu 3+ were doped into TFP host glasses to achieve a tunable white-light emission [9,10]. Because of the low-melting point of TFP glasses, SrSi 2 O 2 N 2 : Eu 2+ and CaAlSiN 3 : Eu 2+ phosphors were added to achieve the full-spectrum emission of visible light under 370 nm excitation [11].…”

Fluorescence regulation derived from Eu3+ in miscible-order fluoride-phosphate blocky phosphor

“…NaYF 4 , a fluoride crystal, has been widely studied as a satisfactory host due to its low phonon energy, high radiative transition rate and good thermal stability [38][39][40][41][42][43][44][45][46][47][48][49]. Meanwhile, tin-fluorophosphate glass is chosen as the precursor glass, which has low-melting temperature to maintain the optical properties of crystals well [50][51][52][53][54]. And the blue emission band from Sn 2+ in the glass matrix can be adopted to replenish the blue component [55][56][57].…”