[19p-G204-1~8] 13.8 Optical properties and light-emitting devices

▲ [19p-G204-4] Effect of Mn-doping on the properties of Mn, Mg-codoped γ-AlON green phosphor

〇(P)Yujin Cho¹, Takashi Takeda¹, Kohsei Takahashi¹, Takashi Kimura¹, Rong-jun Xie¹, Naoto Hirosaki¹, Takashi Sekiguchi¹ (1.NIMS)

Keywords:Mn, Mg-doped AlON, Cathodoluminescence

Recently, narrow-band emitting phosphors attract particular attention for the application in white LED backlight in 8K-LCD TV, mobile phone, or tablet PCs. γ-AlON: Mg²⁺, Mn²⁺ is a promising candidate showing high color purity in green, small thermal quenching and high internal quantum efficiency under blue light irradiation [1, 2]. However, γ-AlON:Mg²⁺, Mn²⁺ has a quite low absorption efficiency due to spin-forbidden transition of 3d⁵ electrons in Mn²⁺. It is necessary to improve luminescence property to be used in w-LED application.In this study, we varied Mn concentration in γ-AlON:Mg²⁺, Mn²⁺ phosphors. The influence of Mn was investigated using PL, CS-SEM, CL, EPMA, XRD, ICP. The PL result shows that Mn²⁺ gives emission band centered at 512nm with 33nm FWHM. The intensity is gradually increased until 30 mol% Mn and then decreased due to the secondary phase generation (Fig. 1). Cross-sectional SEM images indicate that many small voids exist inside of the phosphor at 1mol% of Mn, and then their size grows with Mn doping to 30 mol% (Fig. 2). We consider the huge voids are attributed to the evaporation of Mn during sintering at high temperature. It should be noted that the concentration quenching of γ-AlON:Mg²⁺, Mn²⁺ phosphor is weak comparing with other rare-earth doped phosphors.