Luminescence Behavior of the Ba₂HfF₈:Dy³⁺/Sm³⁺ Nanophosphor for White Light-Emitting Applications

Abstract

Lanthanide (Ln)-doped inorganic materials are widely used in X-ray scintillation, enabling luminescence in the UV to near-infrared region with average lifetime ranging from nanosecond to hours. Fluoride-based inorganic scintillators are favorable due to the low self-absorption. With this motivation, for the first time, this research examines photoluminescence and cathodoluminescence (CL) properties of Dy 3+ -and Sm 3+ -doped Ba 2 HfF 8 (BHF). Singly doped BHF emitted characteristic emission from the doped Ln 3+ ions under UV excitation. The Dy 3+ emission shows only two emission bands, i.e., blue and yellow, ideal for white light emission. Our results clarify the nature of energy transfer between Dy 3+ and Sm 3+ ions in the binary-doped BHF:DySm. No sensitized-type energy transfer was present among the two dopants. However, nonradiative cross-relaxation energy transfer was present between Dy 3+ and Sm 3+ ions, causing the deleterious effect on the overall emission intensity of the Dy 3+ activator ion. The cathode ray-induced CL indicated that all of the samples were extremely sensitive under high-energy irradiation, emitting visible photons. The present material is a promising white-emitting phosphor for white light-emitting diodes and an X-ray scintillator for visible emission.

White-light emitting multi-lanthanide terephthalate thin films by atomic/molecular layer deposition

“…[9][10][11] Blue emitters can also be used in combination with yellow or orange colour emitters such as Ce 3+ or Sm 3+ . 12 A common issue with the lanthanide luminescence is the socalled concentration quenching phenomenon, 13 seen when the emitting Ln 3+ ions are spatially too closely packed. To overcome this issue, the luminescent Ln 3+ ions are typically applied as dopants in relatively small concentrations embedded within a suitable host lattice.…”

“…9–11 Blue emitters can also be used in combination with yellow or orange colour emitters such as Ce 3+ or Sm 3+ . 12…”

Layer-structure-suppressed concentration quenching of Dy3+ luminescence and the realization of a single phase white light-emitting phosphor cooperated with Tm3+

“…In the third type, the co-doped rare earth activated ion is adjusted according to the independent emission intensity of the luminescence centers of each color light to obtain white light, that is, multicenter single-matrix white light. 17,18 This multi-center singlematrix white light has always been concerned, mainly because it seems easier to achieve white light in many substrates. Among all rare earth ions, dysprosium trivalent and thulium seem to be a good choice for achieving white light emission in a single-component host.…”