Intense red-emitting phosphors for LED solid-state lighting

The phosphors Gd2−xEux(MoO4)3 (x = 0.20, 0.40, 0.60, 0.80, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0), Gd0.8−xYxEu1.2(MoO4)3 (x = 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8) and Gd0.2Y0.6−xEu1.2Smx(MoO4)3 (x = 0.02, 0.024, 0.028, 0.032, 0.036, 0.04) were prepared by solid-state reaction technique at 950 °C. The presence of the Y3+ and Sm3+ ions strengthen and broaden the absorption of the phosphors at ∼400 nm. The intense red-emitting phosphor Gd0.2Y0.572Eu1.2Sm0.028(MoO4)3 with orthorhombic structure was obtained. Both Eu3+ and Sm3+ f–f transition absorptions are observed in the excitation spectra, the main emission line is at 616 nm (5D0 → 7F2 transition of Eu3+) and the chromaticity coordinates (x = 0.66, y = 0.33) is very close to the NTSC standard values (x = 0.67, y = 0.33). It is considered to be an efficient red-emitting phosphor for GaN-based light emitting diode (LED).