Synthesis of NaYF4 nanocrystals with predictable phase and shape

In this Full Paper, a water/alcohol/oleic acid system was developed to prepare NaYF4 nanocrystals with predictable size, shape and phase. The structural and kinetic factors that govern the phase and shape evolution of NaYF4 nanocrystals have been carefully studied, and the influence of NaF to y(3+) ratio, reaction time and temperature on the phase and shape evolution of the as-prepared NaYF4 samples was systematically investigated and discussed. It was found that the NaF to y(3+) ratio was responsible for the shape evolution while temperature and reaction time was the key for the phase control of the NaYF4 nanocrystals. This study would be suggestive for the precisely controlled growth of inorganic nanocrystals, especially for those usually crystallizing in diverse crystal structures.