Mn-doped willemite (Zn2SiO4:Mn), which is a zinc silicate green phosphor, is synthesized in an aqueous medium at as low temperature as 250 degreesC. Zn2SiO4:Mn samples showed acicular and spherical shaped particles ranging in size from similar to 50 to 2400 nm: The microstructures of the nanocrystalline products were characterized by XRD, TEM, SEM, and light scattering. The results indicated the formation of solid crystalline structures. The optical emission of 1% and 3% Mn-doped Zn2SiO4 was measured by fluorescence spectroscopy, which give further evidence for the incorporation of Mn within the lattice. This procedure provides an easy and contamination-free method for synthesis of willemite, which commonly is prepared at very high temperatures. (C) 2000 Elsevier Science Ltd. All rights reserved.