The luminescent properties of Eu3+ and Sm3+ doped potassium tungstate phosphor are investigated. The K4–3x (WO4)2 : Eu3+x, Sm3+y phosphor is produced by firing the mixed precursors, followed by re-firing with a flux. The re-firing process results in the defect-free surface and uniform growth of the particles. The strong absorption in the region of ultra violet light is observed due to the 4f-4f electron transitions of the Eu3+ and Sm3+ ions. The doping concentration of europium into potassium tungstate is relatively high, compared to other host materials. It is revealed that the crystal structure is a monoclinic with space group, C2/c. This crystal structure facilitated the Eu3+ ions to be located with the Eu-Eu distance larger than 5 Å so that concentration quenching does not occur even at high doping concentration. The excitation spectrum could be adjusted by the introduction of the samarium. A small amount of the Sm3+ ions that acts as a sensitizer increases the energy absorption peak around 405 nm.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Electrical and Electronic Engineering