Abstract:

Ce,Mn: YAG single crystal for white light emitting diode(LED) was grown by Czochralski method. The structure, valence states of doped Mn and optical properties of the samples were characterized by X-ray diffraction(XRD), X-ray absorption fine structure(XAFS), absorption and photoluminescence spectra. The photoelectric parameters of white LED were also measured by changing the thickness of single crystal and the driving current. Ce,Mn: YAG single crystal shows a broad emission band peak around 526 nm and 566 nm under blue light of 460 nm. The XAFS result shows that the valence states of doped Mn are mostly Mn²⁺ in the Ce,Mn: YAG. Due to the effective energy transfer between Ce³⁺ and Mn²⁺ in YAG single crystal, the bright orange luminescence in the bands peaked at 566 nm are caused by the ⁴T₁→⁶A₁ radiative transitions of Mn²⁺.

Key words: White light emitting diode, Yttrium aluminum garnet, Crystal growth, Luminescence property