Tunable emission, energy transfer, and charge compensation in the CaSb_2O_6:Eu~(3+), Bi~(3+) phosphor

摘要

Novel CaSb_2O_6:Eu~(3+), Bi~(3+) phosphor is synthesized by solid-state reaction method in air. Their crystal structures are investigated. Luminescence properties of CaSb_2O_6:Eu~(3+), CaSb_2O_6:Bi~(3+), and CaSb_2O_6:Eu~(3+), Bi~(3+) phosphors are compared, analyzed and explained, respectively. Tunable emission of CaSb_2O_6:Eu~(3+), Bi~(3+) phosphor with excitation 298 nm can be observed by changing Eu~(3+) or Bi~(3+) concentration. Energy transfer (ET) and charge compensation in CaSb_2O_6:Eu~(3+), Bi~(3+) phosphor are observed and analyzed via its luminescence properties. Lifetimes of CaSb_2O_6:5 %Eu~(3+), yBi~(3+) phosphor (0.5 ≤ y ≤ 5 mol%) are investigated, which further confirm that ET process can be formed between Eu~(3+) ion and Bi~(3+) ion. The luminous mechanism is explained via the energy level diagrams of Bi~(3+) and Eu~(3+) ions. The emission properties indicate that CaSb_2O_6:Eu~(3+), Bi~(3+) phosphor has a potential application for white LEDs based on near UV (～394nm) LED chip.