[19p-235-1~13] 13.8 Optical properties and light-emitting devices

[19p-235-12] Study of Thermal Quenching in Lu₃(Al, Ga)₅O₁₂:Ce by using TRMC Technique (2)

〇Tomotaka Taniguchi¹, Masayoshi Mikami¹, Akinori Saeki² (1.Mitsubishi Chemical, 2.Osaka Univ.)

Keywords:phosphor, thermal quenching, photoconductivity

The thermal quenching in Lu₃Al_5-xGa_xO₁₂:Ce (x = 0-3) has been investigated by using TRMC technique. We examined the temperature dependence of the photoconductivity and obtained the the activation energy(ΔE_dc), which decreased with increasing Ga-content and did not depend on the excitation energies. It is suspected that reduced bandgap energies and shift of Ce 5d levels to higher energies cause the photoionization process and ΔE_dc corresponds to the energy gap between Ce 5d₁ level and the conduction band.