Preparation and optical properties of Sm₂(WO₄) ₃ powders

Sm₂(WO₄)₃ crystals have been synthesized through liquid-phase reaction. The structure, morphology and optical properties of the products have been investigated by Fourier transform infrared spectroscopy (FTIR), X-ray diffractometer, SEM, and spectrofluorometer, respectively. The compound crystallized in the monoclinic hexagonal system, space group C2/c. Heat treat promoted the crystallization and regulated the micro-structure of Sm₂(WO₄)₃. In the Sm ₂(WO₄)₃ host, the WO₄ ^2- group could transfer the energy of near-UV light to Sm³⁺ ions, emitting blue, green and red light at 429 nm ( ⁶P_5/2→⁶H_5/2), 453 nm ( ⁴G_9/2→⁶H_5/2), 495, 507 nm (⁴G_7/2→⁶H_5/2), 563 nm ( ⁴G_5/2→⁶H_5/2), 601 nm ( ^4G_5/2→⁶H_7/2) and 649 nm ( ^4G_5/2→⁶H_9/2), respectively. The ratio of blue, green and red light was appropriate to achieve white light. The Sm₂(WO₄)₃ powders have potential to act as UV absorber for solar cell and may be helpful to the development of white light LED.