Luminescence properties of Tm3+ and Eu3+ co-doped LaPO4 phosphor for white-light emission

For the synthesis of white-light phosphor, red Eu³⁺ with different concentrations was co-doped into the blue LaPO₄:Tm phosphor. It was found that the luminance at wavelength of 454 nm decreased gradually; on the contrary, reddish-orange emission at wavelength 594 nm was strengthened when the Eu³⁺ concentration was increased. The maximum red luminescent intensity was obtained when 7 mol% of Eu³⁺ was doped. Obviously, energy transfer between Tm³⁺ and Eu³⁺ occurred. Consequently, white-light emission was observed.