Synthesis and Photoluminescence of Er3+ and Yb3+ Doped ZnS Nanocrystals

Abstract

ZnS:Er/Yb nanocrystals were synthesized by a hydrothermal method using thioglycolic acid as a stabilizer. The crystalline phases, morphology, chemical bond states and photoluminescent properties of the nanoparticles were characterized by X-ray diffraction, transmission electron microscopy, X-ray photoemission spectroscopy and fluorescence photometer. The results show that most prepared nanoparticles are spherical in shape with an average size of 5 nm, and have cubic zinc blende crystal structure. The emission spectrum of ZnS:Er/Yb nanocrystals excited at 270 nm displays three main peaks at 470, 530 and 580 nm, and the intensity of fluorescence peaks is the strongest for nanocrystals prepared at 120 °C. When ZnS: Er/Yb nanocrystals are excited at 980 nm, the emission peaks around 540 and 650 nm appear, associated with the 4F3/2→4I15/2 and 4F9/2→4I15/2 of Er3+ ions transitions, respectively.