Low-Temperature Synthesis of Nanosize Zn₂SiO₄:Mn²⁺Phosphor from the Precursor Sol in Supercritical Ethanol and its Photoluminescent Properties

The solvothermal reaction in supercritical ethanol produces nanosize Zn2SiO4:Mn2+ from the precursor sol derived from the mixture of zinc acetate, manganese acetate and TEOS. Spherical primary particles of 10–20 nm were grown to the rod-like particles of 10–30 nm diameter and 200–350 nm length by increasing the aging temperature from 200 to 265°C and by optimizing the water/ethanol ratio of sol. This crystal growth improved the intensity of green emission due to the d-d transition of Mn2+ through energy transfer from Zn2SiO4. We discuss the process of Zn2SiO4:Mn2+ crystal growth during the solvothermal reaction in supercritical ethanol.