Rare earth doped semiconductor nanomaterials have attracted wide interest in recent years. Rare earth ions can improve the electrical and luminescent properties of the matri-materials. For rare earth doped materials

many references reported Er doped systems

but La and Ce doped materials was rarely reported

especially for nanomaterials. This kind study will help to develop new luminescent materials. In this paper

rare earth ions La and Ce doped ZnO nanocrystals were prepared by co-precipitation method. XRD results show that the diffraction peaks of the semiconductor nanocrystals widened and the intensity decreased with the increase of rare earth concentrations in the ZnO nanocrystals which means that the size of the ZnO nanocrystals decreased. The results show the doping of rare earth ions can hold back the growth of ZnO nanocrystals. The La and Ce doped samples have the same results. Strong and narrow blue photoluminescence at 443 nm was observed in 1% Ce doped ZnO nanocrystals excited at 380 nm. It was ascribed to oxide vacancy defect caused by CeO

2

new phase. This blue luminescence is important to the preparation of short wave apparatus. The photoluminescence of La ions doped ZnO nanocrystals was a wide peak from 418 nm to 610 nm.