[13p-PA10-1~21] 13.8 Optical properties and light-emitting devices

[13p-PA10-13] Afterglow characteristics of CaS:Eu²⁺,Tm³⁺ phosphors

〇(M1)Yuki Tamura¹, Tsuyoshi Okuno¹, Yoriko Suda², Yasushi Nanai³ (1.The Univ. of Electro-Communications, 2.Tokyo Univ. of Technology, 3.Aoyama Gakuin Univ.)

Keywords:phosphor, afterglow, europium

It is known that CaS:Eu²⁺,Tm³⁺ is a phosphor that emits red afterglow. However, there is no report on the optimum addition concentration of rare earth ions or the absorption wavelength dependence of red afterglow. Therefore, in this study, samples were prepared by changing the concentration of Eu²⁺, and the luminescence characteristics were evaluated. Normal afterglow phosphors are excited by ultraviolet light, but photon energy from a blue LED is stored in CaS:Eu²⁺,Tm³⁺