Luminescent materials in display and biomedical applications Recently much research attention has been paid to the rare earth ions since they bear unique electronic and optical characteristics arising from their 4f electrons. The luminescence features of rare earth ions include high luminescence quantum yield narrow bandwidth long lived emission large Stokes shifts ligand dependent luminescence sensitization which have received startling interest because of the continuously expanding need for luminescent materials meeting the stringent requirements of telecommunication lighting electroluminescent devices (bio ) analytical sensors bioimaging set ups and solar cells. In particular rare earth orthophosphates (REPO4) have been extensively studied because of their potential applications in color displays field effect transistors optoelectronics solar cells and light sources