In the present study, synthesis, characterization, of dual mode emission (Up and downconversion) in lanthanide-doped NaYF4 nanorods is presented. The unique and rich energy-level structure of these lanthanide ions allows for efficient spectral conversion, including up and downconversion processes mediated by resonant energy transfer between neighboring lanthanide ions. The careful examination of nanorods indicates the perfect uniformity, monodispersity and well defined crystallographic facets. Er 3 + , Yb 3 + doped NCs exhibit green/red dual mode emission with low power density. As solar cells have majority of losses due to spectral mismatch, so with the help of these dual mode emission of nanorods can be utilized as up/down converter to increase the efficiency solar cell.