LaVO_4:Eu Phosphor films with enhanced Eu solubility

摘要

Eu doped rare-earth orthovanadates are known to be good red phosphor materials. In particular, LaVO_4:Eu is a promising candidate due to the low Eu-site point symmetry, and thus high dipole transition probability within Judd-Ofelt theory. However, the low solubility limit (<3 mol %) of Eu in LaVO_4 prevents its efficient use as a phosphor. We present optical evidence of enhanced Eu solubility as high as 10 mol % in LaVO_4:Eu thin films grown by pulsed laser deposition and postannealing. The photoluminescent intensity exceeded that of YVO_4:Eu thin films when excited below the host bandgap, indicating stronger direct emission of Eu in LaVO_4.